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Stefan Frässle; Frieder M Paulus; Sören Krach; Stefan Robert Schweinberger; Klaas Enno Stephan; Andreas Jansen Mechanisms of hemispheric lateralization: Asymmetric interhemispheric recruitment in the face perception network Journal Article NeuroImage, 124 , pp. 977–988, 2016. @article{Fraessle2016a, title = {Mechanisms of hemispheric lateralization: Asymmetric interhemispheric recruitment in the face perception network}, author = {Stefan Frässle and Frieder M Paulus and Sören Krach and Stefan Robert Schweinberger and Klaas Enno Stephan and Andreas Jansen}, doi = {10.1016/j.neuroimage.2015.09.055}, year = {2016}, date = {2016-01-01}, journal = {NeuroImage}, volume = {124}, pages = {977--988}, publisher = {Elsevier Inc.}, abstract = {Perceiving human faces constitutes a fundamental ability of the human mind, integrating a wealth of information essential for social interactions in everyday life. Neuroimaging studies have unveiled a distributed neural network consisting of multiple brain regions in both hemispheres. Whereas the individual regions in the face perception network and the right-hemispheric dominance for face processing have been subject to intensive research, the functional integration among these regions and hemispheres has received considerably less attention. Using dynamic causal modeling (DCM) for fMRI, we analyzed the effective connectivity between the core regions in the face perception network of healthy humans to unveil the mechanisms underlying both intra- and interhemispheric integration. Our results suggest that the right-hemispheric lateralization of the network is due to an asymmetric face-specific interhemispheric recruitment at an early processing stage - that is, at the level of the occipital face area (OFA) but not the fusiform face area (FFA). As a structural correlate, we found that OFA gray matter volume was correlated with this asymmetric interhemispheric recruitment. Furthermore, exploratory analyses revealed that interhemispheric connection asymmetries were correlated with the strength of pupil constriction in response to faces, a measure with potential sensitivity to holistic (as opposed to feature-based) processing of faces. Overall, our findings thus provide a mechanistic description for lateralized processes in the core face perception network, point to a decisive role of interhemispheric integration at an early stage of face processing among bilateral OFA, and tentatively indicate a relation to individual variability in processing strategies for faces. These findings provide a promising avenue for systematic investigations of the potential role of interhemispheric integration in future studies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Perceiving human faces constitutes a fundamental ability of the human mind, integrating a wealth of information essential for social interactions in everyday life. Neuroimaging studies have unveiled a distributed neural network consisting of multiple brain regions in both hemispheres. Whereas the individual regions in the face perception network and the right-hemispheric dominance for face processing have been subject to intensive research, the functional integration among these regions and hemispheres has received considerably less attention. Using dynamic causal modeling (DCM) for fMRI, we analyzed the effective connectivity between the core regions in the face perception network of healthy humans to unveil the mechanisms underlying both intra- and interhemispheric integration. Our results suggest that the right-hemispheric lateralization of the network is due to an asymmetric face-specific interhemispheric recruitment at an early processing stage - that is, at the level of the occipital face area (OFA) but not the fusiform face area (FFA). As a structural correlate, we found that OFA gray matter volume was correlated with this asymmetric interhemispheric recruitment. Furthermore, exploratory analyses revealed that interhemispheric connection asymmetries were correlated with the strength of pupil constriction in response to faces, a measure with potential sensitivity to holistic (as opposed to feature-based) processing of faces. Overall, our findings thus provide a mechanistic description for lateralized processes in the core face perception network, point to a decisive role of interhemispheric integration at an early stage of face processing among bilateral OFA, and tentatively indicate a relation to individual variability in processing strategies for faces. These findings provide a promising avenue for systematic investigations of the potential role of interhemispheric integration in future studies. |
Benedetta Franceschiello; Lorenzo Di Sopra; Astrid Minier; Silvio Ionta; David Zeugin; Michael P Notter; Jessica A M Bastiaansen; João Jorge; Jérôme Yerly; Matthias Stuber; Micah M Murray 3-dimensional magnetic resonance imaging of the freely moving human eye Journal Article Progress in Neurobiology, 194 , pp. 1–8, 2020. @article{Franceschiello2020, title = {3-dimensional magnetic resonance imaging of the freely moving human eye}, author = {Benedetta Franceschiello and Lorenzo {Di Sopra} and Astrid Minier and Silvio Ionta and David Zeugin and Michael P Notter and Jessica A M Bastiaansen and Jo{ã}o Jorge and Jér{ô}me Yerly and Matthias Stuber and Micah M Murray}, doi = {10.1016/j.pneurobio.2020.101885}, year = {2020}, date = {2020-01-01}, journal = {Progress in Neurobiology}, volume = {194}, pages = {1--8}, abstract = {Eye motion is a major confound for magnetic resonance imaging (MRI) in neuroscience or ophthalmology. Currently, solutions toward eye stabilisation include participants fixating or administration of paralytics/anaesthetics. We developed a novel MRI protocol for acquiring 3-dimensional images while the eye freely moves. Eye motion serves as the basis for image reconstruction, rather than an impediment. We fully reconstruct videos of the moving eye and head. We quantitatively validate data quality with millimetre resolution in two ways for individual participants. First, eye position based on reconstructed images correlated with simultaneous eye-tracking. Second, the reconstructed images preserve anatomical properties; the eye's axial length measured from MRI images matched that obtained with ocular biometry. The technique operates on a standard clinical setup, without necessitating specialized hardware, facilitating wide deployment. In clinical practice, we anticipate that this may help reduce burdens on both patients and infrastructure, by integrating multiple varieties of assessments into a single comprehensive session. More generally, our protocol is a harbinger for removing the necessity of fixation, thereby opening new opportunities for ethologically-valid, naturalistic paradigms, the inclusion of populations typically unable to stably fixate, and increased translational research such as in awake animals whose eye movements constitute an accessible behavioural readout.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Eye motion is a major confound for magnetic resonance imaging (MRI) in neuroscience or ophthalmology. Currently, solutions toward eye stabilisation include participants fixating or administration of paralytics/anaesthetics. We developed a novel MRI protocol for acquiring 3-dimensional images while the eye freely moves. Eye motion serves as the basis for image reconstruction, rather than an impediment. We fully reconstruct videos of the moving eye and head. We quantitatively validate data quality with millimetre resolution in two ways for individual participants. First, eye position based on reconstructed images correlated with simultaneous eye-tracking. Second, the reconstructed images preserve anatomical properties; the eye's axial length measured from MRI images matched that obtained with ocular biometry. The technique operates on a standard clinical setup, without necessitating specialized hardware, facilitating wide deployment. In clinical practice, we anticipate that this may help reduce burdens on both patients and infrastructure, by integrating multiple varieties of assessments into a single comprehensive session. More generally, our protocol is a harbinger for removing the necessity of fixation, thereby opening new opportunities for ethologically-valid, naturalistic paradigms, the inclusion of populations typically unable to stably fixate, and increased translational research such as in awake animals whose eye movements constitute an accessible behavioural readout. |
Jeremy Freeman; G J Brouwer; David J Heeger; Elisha P Merriam Orientation decoding depends on maps, not columns Journal Article Journal of Neuroscience, 31 (13), pp. 4792–4804, 2011. @article{Freeman2011a, title = {Orientation decoding depends on maps, not columns}, author = {Jeremy Freeman and G J Brouwer and David J Heeger and Elisha P Merriam}, doi = {10.1523/JNEUROSCI.5160-10.2011}, year = {2011}, date = {2011-01-01}, journal = {Journal of Neuroscience}, volume = {31}, number = {13}, pages = {4792--4804}, abstract = {The representation of orientation in primary visual cortex (V1) has been examined at a fine spatial scale corresponding to the columnar architecture. We present functional magnetic resonance imaging (fMRI) measurements providing evidence for a topographic map of orientation preference in human V1 at a much coarser scale, in register with the angular-position component of the retinotopic map of V1. This coarse-scale orientation map provides a parsimonious explanation for why multivariate pattern analysis methods succeed in decoding stimulus orientation from fMRI measurements, challenging the widely held assumption that decoding results reflect sampling of spatial irregularities in the fine-scale columnar architecture. Decoding stimulus attributes and cognitive states from fMRI measurements has proven useful for a number of applications, but our results demonstrate that the interpretation cannot assume decoding reflects or exploits columnar organization.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The representation of orientation in primary visual cortex (V1) has been examined at a fine spatial scale corresponding to the columnar architecture. We present functional magnetic resonance imaging (fMRI) measurements providing evidence for a topographic map of orientation preference in human V1 at a much coarser scale, in register with the angular-position component of the retinotopic map of V1. This coarse-scale orientation map provides a parsimonious explanation for why multivariate pattern analysis methods succeed in decoding stimulus orientation from fMRI measurements, challenging the widely held assumption that decoding results reflect sampling of spatial irregularities in the fine-scale columnar architecture. Decoding stimulus attributes and cognitive states from fMRI measurements has proven useful for a number of applications, but our results demonstrate that the interpretation cannot assume decoding reflects or exploits columnar organization. |
Jeremy Freeman; David J Heeger; Elisha P Merriam Coarse-scale biases for spirals and orientation in human visual cortex Journal Article Journal of Neuroscience, 33 (50), pp. 19695–19703, 2013. @article{Freeman2013, title = {Coarse-scale biases for spirals and orientation in human visual cortex}, author = {Jeremy Freeman and David J Heeger and Elisha P Merriam}, doi = {10.1523/JNEUROSCI.0889-13.2013}, year = {2013}, date = {2013-01-01}, journal = {Journal of Neuroscience}, volume = {33}, number = {50}, pages = {19695--19703}, abstract = {Multivariate decoding analyses are widely applied to functional magnetic resonance imaging (fMRI) data, but there is controversy over their interpretation. Orientation decoding in primary visual cortex (V1) reflects coarse-scale biases, including an over-representation of radial orientations. But fMRI responses to clockwise and counter-clockwise spirals can also be decoded. Because these stimuli are matched for radial orientation, while differing in local orientation, it has been argued that fine-scale columnar selectivity for orientation contributes to orientation decoding. We measured fMRI responses in human V1 to both oriented gratings and spirals. Responses to oriented gratings exhibited a complex topography, including a radial bias that was most pronounced in the peripheral representation, and a near-vertical bias that was most pronounced near the foveal representation. Responses to clockwise and counter-clockwise spirals also exhibited coarse-scale organization, at the scale of entire visual quadrants. The preference of each voxel for clockwise or counter-clockwise spirals was predicted from the preferences of that voxel for orientation and spatial position (i.e., within the retinotopic map). Our results demonstrate a bias for local stimulus orientation that has a coarse spatial scale, is robust across stimulus classes (spirals and gratings), and suffices to explain decoding from fMRI responses in V1.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Multivariate decoding analyses are widely applied to functional magnetic resonance imaging (fMRI) data, but there is controversy over their interpretation. Orientation decoding in primary visual cortex (V1) reflects coarse-scale biases, including an over-representation of radial orientations. But fMRI responses to clockwise and counter-clockwise spirals can also be decoded. Because these stimuli are matched for radial orientation, while differing in local orientation, it has been argued that fine-scale columnar selectivity for orientation contributes to orientation decoding. We measured fMRI responses in human V1 to both oriented gratings and spirals. Responses to oriented gratings exhibited a complex topography, including a radial bias that was most pronounced in the peripheral representation, and a near-vertical bias that was most pronounced near the foveal representation. Responses to clockwise and counter-clockwise spirals also exhibited coarse-scale organization, at the scale of entire visual quadrants. The preference of each voxel for clockwise or counter-clockwise spirals was predicted from the preferences of that voxel for orientation and spatial position (i.e., within the retinotopic map). Our results demonstrate a bias for local stimulus orientation that has a coarse spatial scale, is robust across stimulus classes (spirals and gratings), and suffices to explain decoding from fMRI responses in V1. |
Matthias Fritsche; Samuel J D Lawrence; Floris P de Lange Temporal tuning of repetition suppression across the visual cortex Journal Article Journal of Neurophysiology, 123 (1), pp. 224–233, 2020. @article{Fritsche2020, title = {Temporal tuning of repetition suppression across the visual cortex}, author = {Matthias Fritsche and Samuel J D Lawrence and Floris P de Lange}, doi = {10.1152/jn.00582.2019}, year = {2020}, date = {2020-01-01}, journal = {Journal of Neurophysiology}, volume = {123}, number = {1}, pages = {224--233}, abstract = {The visual system adapts to its recent history. A phenomenon related to this is repetition suppression (RS), a reduction in neural responses to repeated compared with nonrepeated visual input. An intriguing hypothesis is that the timescale over which RS occurs across the visual hierarchy is tuned to the temporal statistics of visual input features, which change rapidly in low-level areas but are more stable in higher level areas. Here, we tested this hypothesis by studying the influence of the temporal lag between successive visual stimuli on RS throughout the visual system using functional (f)MRI. Twelve human volunteers engaged in four fMRI sessions in which we characterized the blood oxygen level-dependent response to pairs of repeated and nonrepeated natural images with interstimulus intervals (ISI) ranging from 50 to 1,000 ms to quantify the temporal tuning of RS along the posterior-anterior axis of the visual system. As expected, RS was maximal for short ISIs and decayed with increasing ISI. Crucially, however, and against our hypothesis, RS decayed at a similar rate in early and late visual areas. This finding challenges the prevailing view that the timescale of RS increases along the posterior-anterior axis of the visual system and suggests that RS is not tuned to temporal input regularities.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The visual system adapts to its recent history. A phenomenon related to this is repetition suppression (RS), a reduction in neural responses to repeated compared with nonrepeated visual input. An intriguing hypothesis is that the timescale over which RS occurs across the visual hierarchy is tuned to the temporal statistics of visual input features, which change rapidly in low-level areas but are more stable in higher level areas. Here, we tested this hypothesis by studying the influence of the temporal lag between successive visual stimuli on RS throughout the visual system using functional (f)MRI. Twelve human volunteers engaged in four fMRI sessions in which we characterized the blood oxygen level-dependent response to pairs of repeated and nonrepeated natural images with interstimulus intervals (ISI) ranging from 50 to 1,000 ms to quantify the temporal tuning of RS along the posterior-anterior axis of the visual system. As expected, RS was maximal for short ISIs and decayed with increasing ISI. Crucially, however, and against our hypothesis, RS decayed at a similar rate in early and late visual areas. This finding challenges the prevailing view that the timescale of RS increases along the posterior-anterior axis of the visual system and suggests that RS is not tuned to temporal input regularities. |
Marc Galanter; Zoran Josipovic; Helen Dermatis; Jochen Weber; Mary Alice Millard An initial fMRI study on neural correlates of prayer in members of Alcoholics Anonymous Journal Article American Journal of Drug and Alcohol Abuse, 43 (1), pp. 44–54, 2017. @article{Galanter2017, title = {An initial fMRI study on neural correlates of prayer in members of Alcoholics Anonymous}, author = {Marc Galanter and Zoran Josipovic and Helen Dermatis and Jochen Weber and Mary Alice Millard}, doi = {10.3109/00952990.2016.1141912}, year = {2017}, date = {2017-01-01}, journal = {American Journal of Drug and Alcohol Abuse}, volume = {43}, number = {1}, pages = {44--54}, publisher = {Informa Healthcare}, abstract = {Background: Many individuals with alcohol-use disorders who had experienced alcohol craving before joining Alcoholics Anonymous (AA) report little or no craving after becoming long-term members. Their use of AA prayers may contribute to this. Neural mechanisms underlying this process have not been delineated. Objective: To define experiential and neural correlates of diminished alcohol craving followingAA prayers amongmembers with long-termabstinence. Methods: Twenty AAmembers with long-term abstinence participated. Self-report measures and functional magnetic resonance imaging of differential neural response to alcohol-craving-inducing images were obtained in three conditions: after reading of AA prayers, after reading irrelevant news, and with passive viewing. Random-effects robust regressions were computed for the main effect (prayer textgreater passive + news) and for estimating the correlations between themain effect and the self-report measures. Results: Compared to the other two conditions, the prayer condition was characterized by: less self-reported craving; increased activation in left-anterior middle frontal gyrus, left superior parietal lobule, bilateral precuneus, and bilateral posterior middle temporal gyrus. Craving following prayer was inversely correlated with activation in brain areas associated with self-referential processing and the default mode network, and with characteristics reflecting AA program involvement. Conclusion:AA members' prayer was asso- ciated with a relative reduction in self-reported craving and with concomitant engagement of neural mechanisms that reflect control of attention and emotion. These findings suggest neural processes underlying the apparent effectiveness of AA prayer.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: Many individuals with alcohol-use disorders who had experienced alcohol craving before joining Alcoholics Anonymous (AA) report little or no craving after becoming long-term members. Their use of AA prayers may contribute to this. Neural mechanisms underlying this process have not been delineated. Objective: To define experiential and neural correlates of diminished alcohol craving followingAA prayers amongmembers with long-termabstinence. Methods: Twenty AAmembers with long-term abstinence participated. Self-report measures and functional magnetic resonance imaging of differential neural response to alcohol-craving-inducing images were obtained in three conditions: after reading of AA prayers, after reading irrelevant news, and with passive viewing. Random-effects robust regressions were computed for the main effect (prayer textgreater passive + news) and for estimating the correlations between themain effect and the self-report measures. Results: Compared to the other two conditions, the prayer condition was characterized by: less self-reported craving; increased activation in left-anterior middle frontal gyrus, left superior parietal lobule, bilateral precuneus, and bilateral posterior middle temporal gyrus. Craving following prayer was inversely correlated with activation in brain areas associated with self-referential processing and the default mode network, and with characteristics reflecting AA program involvement. Conclusion:AA members' prayer was asso- ciated with a relative reduction in self-reported craving and with concomitant engagement of neural mechanisms that reflect control of attention and emotion. These findings suggest neural processes underlying the apparent effectiveness of AA prayer. |
Kathleen A Garrison; Stephanie S O'malley; Ralitza Gueorguieva; Suchitra Krishnan-Sarin A fMRI study on the impact of advertising for flavored e-cigarettes on susceptible young adults Journal Article Drug and Alcohol Dependence, 186 , pp. 233–241, 2018. @article{Garrison2018, title = {A fMRI study on the impact of advertising for flavored e-cigarettes on susceptible young adults}, author = {Kathleen A Garrison and Stephanie S O'malley and Ralitza Gueorguieva and Suchitra Krishnan-Sarin}, doi = {10.1016/j.drugalcdep.2018.01.026}, year = {2018}, date = {2018-01-01}, journal = {Drug and Alcohol Dependence}, volume = {186}, pages = {233--241}, abstract = {Background: E-cigarettes are sold in flavors such as "skittles," "strawberrylicious," and "juicy fruit," and no restrictions are in place on marketing e-cigarettes to youth. Sweets/fruits depicted in e-cigarette advertisements may increase their appeal to youth and interfere with health warnings. This study tested a brain biomarker of product preference for sweet/fruit versus tobacco flavor e-cigarettes, and whether advertising for flavors interfered with warning labels. Methods: Participants (N = 26) were college-age young adults who had tried an e-cigarette and were susceptible to future e-cigarette use. They viewed advertisements in fMRI for sweet/fruit and tobacco flavor e-cigarettes, menthol and regular cigarettes, and control images of sweets/fruits/mints with no tobacco product. Cue-reactivity was measured in the nucleus accumbens, a brain biomarker of product preference. Advertisements randomly contained warning labels, and recognition of health warnings was tested post-scan. Visual attention was measured using eye-tracking. Results: There was a significant effect of e-cigarette condition (sweet/tobacco/control) on nucleus accumbens activity, that was not found for cigarette condition (menthol/regular/control). Nucleus accumbens activity was greater for sweet/fruit versus tobacco flavor e-cigarette advertisements and did not differ compared with control images of sweets and fruits. Greater nucleus accumbens activity was correlated with poorer memory for health warnings. Conclusions: These and exploratory eye-tracking findings suggest that advertising for sweet/fruit flavors may increase positive associations with e-cigarettes and/or override negative associations with tobacco, and interfere with health warnings, suggesting that one way to reduce the appeal of e-cigarettes to youth and educate youth about e-cigarette health risks is to regulate advertising for flavors.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: E-cigarettes are sold in flavors such as "skittles," "strawberrylicious," and "juicy fruit," and no restrictions are in place on marketing e-cigarettes to youth. Sweets/fruits depicted in e-cigarette advertisements may increase their appeal to youth and interfere with health warnings. This study tested a brain biomarker of product preference for sweet/fruit versus tobacco flavor e-cigarettes, and whether advertising for flavors interfered with warning labels. Methods: Participants (N = 26) were college-age young adults who had tried an e-cigarette and were susceptible to future e-cigarette use. They viewed advertisements in fMRI for sweet/fruit and tobacco flavor e-cigarettes, menthol and regular cigarettes, and control images of sweets/fruits/mints with no tobacco product. Cue-reactivity was measured in the nucleus accumbens, a brain biomarker of product preference. Advertisements randomly contained warning labels, and recognition of health warnings was tested post-scan. Visual attention was measured using eye-tracking. Results: There was a significant effect of e-cigarette condition (sweet/tobacco/control) on nucleus accumbens activity, that was not found for cigarette condition (menthol/regular/control). Nucleus accumbens activity was greater for sweet/fruit versus tobacco flavor e-cigarette advertisements and did not differ compared with control images of sweets and fruits. Greater nucleus accumbens activity was correlated with poorer memory for health warnings. Conclusions: These and exploratory eye-tracking findings suggest that advertising for sweet/fruit flavors may increase positive associations with e-cigarettes and/or override negative associations with tobacco, and interfere with health warnings, suggesting that one way to reduce the appeal of e-cigarettes to youth and educate youth about e-cigarette health risks is to regulate advertising for flavors. |
Jan Willem de Gee; Olympia Colizoli; Niels A Kloosterman; Tomas Knapen; Sander Nieuwenhuis; Tobias H Donner Dynamic modulation of decision biases by brainstem arousal systems Journal Article eLife, 6 , pp. 1–36, 2017. @article{Gee2017, title = {Dynamic modulation of decision biases by brainstem arousal systems}, author = {Jan Willem de Gee and Olympia Colizoli and Niels A Kloosterman and Tomas Knapen and Sander Nieuwenhuis and Tobias H Donner}, doi = {10.7554/eLife.23232}, year = {2017}, date = {2017-01-01}, journal = {eLife}, volume = {6}, pages = {1--36}, abstract = {Decision-makers often arrive at different choices when faced with repeated presentations of the same evidence. Variability of behavior is commonly attributed to noise in the brain's decision-making machinery. We hypothesized that phasic responses of brainstem arousal systems are a significant source of this variability. We tracked pupil responses (a proxy of phasic arousal) during sensory-motor decisions in humans, across different sensory modalities and task protocols. Large pupil responses generally predicted a reduction in decision bias. Using fMRI, we showed that the pupil-linked bias reduction was (i) accompanied by a modulation of choice-encoding pattern signals in parietal and prefrontal cortex and (ii) predicted by phasic, pupil-linked responses of a number of neuromodulatory brainstem centers involved in the control of cortical arousal state, including the noradrenergic locus coeruleus. We conclude that phasic arousal suppresses decision bias on a trial-by-trial basis, thus accounting for a significant component of the variability of choice behavior.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Decision-makers often arrive at different choices when faced with repeated presentations of the same evidence. Variability of behavior is commonly attributed to noise in the brain's decision-making machinery. We hypothesized that phasic responses of brainstem arousal systems are a significant source of this variability. We tracked pupil responses (a proxy of phasic arousal) during sensory-motor decisions in humans, across different sensory modalities and task protocols. Large pupil responses generally predicted a reduction in decision bias. Using fMRI, we showed that the pupil-linked bias reduction was (i) accompanied by a modulation of choice-encoding pattern signals in parietal and prefrontal cortex and (ii) predicted by phasic, pupil-linked responses of a number of neuromodulatory brainstem centers involved in the control of cortical arousal state, including the noradrenergic locus coeruleus. We conclude that phasic arousal suppresses decision bias on a trial-by-trial basis, thus accounting for a significant component of the variability of choice behavior. |
Hanna Gertz; Maximilian Hilger; Mathias Hegele; Katja Fiehler Violating instructed human agency: An fMRI study on ocular tracking of biological and nonbiological motion stimuli Journal Article NeuroImage, 138 , pp. 109–122, 2016. @article{Gertz2016, title = {Violating instructed human agency: An fMRI study on ocular tracking of biological and nonbiological motion stimuli}, author = {Hanna Gertz and Maximilian Hilger and Mathias Hegele and Katja Fiehler}, doi = {10.1016/j.neuroimage.2016.05.043}, year = {2016}, date = {2016-01-01}, journal = {NeuroImage}, volume = {138}, pages = {109--122}, publisher = {Elsevier Inc.}, abstract = {Previous studies have shown that beliefs about the human origin of a stimulus are capable of modulating the coupling of perception and action. Such beliefs can be based on top-down recognition of the identity of an actor or bottom-up observation of the behavior of the stimulus. Instructed human agency has been shown to lead to superior tracking performance of a moving dot as compared to instructed computer agency, especially when the dot followed a biological velocity profile and thus matched the predicted movement, whereas a violation of instructed human agency by a nonbiological dot motion impaired oculomotor tracking (Zwickel et al., 2012). This suggests that the instructed agency biases the selection of predictive models on the movement trajectory of the dot motion. The aim of the present fMRI study was to examine the neural correlates of top-down and bottom-up modulations of perception–action couplings by manipulating the instructed agency (human action vs. computer-generated action) and the observable behavior of the stimulus (biological vs. nonbiological velocity profile). To this end, participants performed an oculomotor tracking task in an MRI environment. Oculomotor tracking activated areas of the eye movement network. A right-hemisphere occipito-temporal cluster comprising the motion-sensitive area V5 showed a preference for the biological as compared to the nonbiological velocity profile. Importantly, a mismatch between instructed human agency and a nonbiological velocity profile primarily activated medial–frontal areas comprising the frontal pole, the paracingulate gyrus, and the anterior cingulate gyrus, as well as the cerebellum and the supplementary eye field as part of the eye movement network. This mismatch effect was specific to the instructed human agency and did not occur in conditions with a mismatch between instructed computer agency and a biological velocity profile. Our results support the hypothesis that humans activate a specific predictive model for biological movements based on their own motor expertise. A violation of this predictive model causes costs as the movement needs to be corrected in accordance with incoming (nonbiological) sensory information.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Previous studies have shown that beliefs about the human origin of a stimulus are capable of modulating the coupling of perception and action. Such beliefs can be based on top-down recognition of the identity of an actor or bottom-up observation of the behavior of the stimulus. Instructed human agency has been shown to lead to superior tracking performance of a moving dot as compared to instructed computer agency, especially when the dot followed a biological velocity profile and thus matched the predicted movement, whereas a violation of instructed human agency by a nonbiological dot motion impaired oculomotor tracking (Zwickel et al., 2012). This suggests that the instructed agency biases the selection of predictive models on the movement trajectory of the dot motion. The aim of the present fMRI study was to examine the neural correlates of top-down and bottom-up modulations of perception–action couplings by manipulating the instructed agency (human action vs. computer-generated action) and the observable behavior of the stimulus (biological vs. nonbiological velocity profile). To this end, participants performed an oculomotor tracking task in an MRI environment. Oculomotor tracking activated areas of the eye movement network. A right-hemisphere occipito-temporal cluster comprising the motion-sensitive area V5 showed a preference for the biological as compared to the nonbiological velocity profile. Importantly, a mismatch between instructed human agency and a nonbiological velocity profile primarily activated medial–frontal areas comprising the frontal pole, the paracingulate gyrus, and the anterior cingulate gyrus, as well as the cerebellum and the supplementary eye field as part of the eye movement network. This mismatch effect was specific to the instructed human agency and did not occur in conditions with a mismatch between instructed computer agency and a biological velocity profile. Our results support the hypothesis that humans activate a specific predictive model for biological movements based on their own motor expertise. A violation of this predictive model causes costs as the movement needs to be corrected in accordance with incoming (nonbiological) sensory information. |
Stephan Geuter; Sabrina Boll; Falk Eippert; Christian Büchel Functional dissociation of stimulus intensity encoding and predictive coding of pain in the insula Journal Article eLife, 6 , pp. 1–22, 2017. @article{Geuter2017, title = {Functional dissociation of stimulus intensity encoding and predictive coding of pain in the insula}, author = {Stephan Geuter and Sabrina Boll and Falk Eippert and Christian Büchel}, doi = {10.7554/eLife.24770}, year = {2017}, date = {2017-01-01}, journal = {eLife}, volume = {6}, pages = {1--22}, abstract = {textlessptextgreaterThe computational principles by which the brain creates a painful experience from nociception are still unknown. Classic theories suggest that cortical regions either reflect stimulus intensity or additive effects of intensity and expectations, respectively. By contrast, predictive coding theories provide a unified framework explaining how perception is shaped by the integration of beliefs about the world with mismatches resulting from the comparison of these believes against sensory input. Using functional magnetic resonance imaging during a probabilistic heat pain paradigm, we investigated which computations underlie pain perception. Skin conductance, pupil dilation, and anterior insula responses to cued pain stimuli strictly followed the response patterns hypothesized by the predictive coding model, whereas posterior insula encoded stimulus intensity. This novel functional dissociation of pain processing within the insula together with previously observed alterations in chronic pain offer a novel interpretation of aberrant pain processing as disturbed weighting of predictions and prediction errors.textless/ptextgreater}, keywords = {}, pubstate = {published}, tppubtype = {article} } textlessptextgreaterThe computational principles by which the brain creates a painful experience from nociception are still unknown. Classic theories suggest that cortical regions either reflect stimulus intensity or additive effects of intensity and expectations, respectively. By contrast, predictive coding theories provide a unified framework explaining how perception is shaped by the integration of beliefs about the world with mismatches resulting from the comparison of these believes against sensory input. Using functional magnetic resonance imaging during a probabilistic heat pain paradigm, we investigated which computations underlie pain perception. Skin conductance, pupil dilation, and anterior insula responses to cued pain stimuli strictly followed the response patterns hypothesized by the predictive coding model, whereas posterior insula encoded stimulus intensity. This novel functional dissociation of pain processing within the insula together with previously observed alterations in chronic pain offer a novel interpretation of aberrant pain processing as disturbed weighting of predictions and prediction errors.textless/ptextgreater |
Kyle M Gilbert; Martyn L Klassen; Alexander Mashkovtsev; Peter Zeman; Ravi S Menon; Joseph S Gati Radiofrequency coil for routine ultra-high-field imaging with an unobstructed visual field Journal Article NMR in Biomedicine, pp. 1–16, 2020. @article{Gilbert2020, title = {Radiofrequency coil for routine ultra-high-field imaging with an unobstructed visual field}, author = {Kyle M Gilbert and Martyn L Klassen and Alexander Mashkovtsev and Peter Zeman and Ravi S Menon and Joseph S Gati}, doi = {10.1002/nbm.4457}, year = {2020}, date = {2020-01-01}, journal = {NMR in Biomedicine}, pages = {1--16}, abstract = {Many neuroscience applications have adopted functional MRI as a tool to investigate the healthy and diseased brain during the completion of a task. While ultra-high-field MRI has allowed for improved contrast and signal-to-noise ratios during functional MRI studies, it remains a challenge to create local radiofrequency coils that can accommodate an unobstructed visual field and be suitable for routine use, while at the same time not compromise performance. Performance (both during transmission and reception) can be improved by using close-fitting coils; however, maintaining sensitivity over the whole brain often requires the introduction of coil elements proximal to the eyes, thereby partially occluding the subject's visual field. This study presents a 7 T head coil, with eight transmit dipoles and 32 receive loops, that is designed to remove visual obstructions from the subject's line of sight, allowing for an unencumbered view of visual stimuli, the reduction of anxiety induced from small enclosures, and the potential for eye-tracking measurements. The coil provides a practical solution for routine imaging, including a split design (anterior and posterior halves) that facilitates subject positioning, including those with impaired mobility, and the placement of devices required for patient comfort and motion reduction. The transmit and receive coils displayed no degradation of performance due to adaptions to the design topology (both mechanical and electrical) required to create an unobstructed visual field. All computer-aided design files, electromagnetic simulation models, transmit field maps and local specific absorption rate matrices are provided to promote reproduction.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Many neuroscience applications have adopted functional MRI as a tool to investigate the healthy and diseased brain during the completion of a task. While ultra-high-field MRI has allowed for improved contrast and signal-to-noise ratios during functional MRI studies, it remains a challenge to create local radiofrequency coils that can accommodate an unobstructed visual field and be suitable for routine use, while at the same time not compromise performance. Performance (both during transmission and reception) can be improved by using close-fitting coils; however, maintaining sensitivity over the whole brain often requires the introduction of coil elements proximal to the eyes, thereby partially occluding the subject's visual field. This study presents a 7 T head coil, with eight transmit dipoles and 32 receive loops, that is designed to remove visual obstructions from the subject's line of sight, allowing for an unencumbered view of visual stimuli, the reduction of anxiety induced from small enclosures, and the potential for eye-tracking measurements. The coil provides a practical solution for routine imaging, including a split design (anterior and posterior halves) that facilitates subject positioning, including those with impaired mobility, and the placement of devices required for patient comfort and motion reduction. The transmit and receive coils displayed no degradation of performance due to adaptions to the design topology (both mechanical and electrical) required to create an unobstructed visual field. All computer-aided design files, electromagnetic simulation models, transmit field maps and local specific absorption rate matrices are provided to promote reproduction. |
Lauren R Godier; Jessica C Scaife; Sven Braeutigam; Rebecca J Park Enhanced early neuronal processing of food pictures in Anorexia Nervosa: A magnetoencephalography study Journal Article Psychiatry Journal, 2016 , pp. 1–13, 2016. @article{Godier2016, title = {Enhanced early neuronal processing of food pictures in Anorexia Nervosa: A magnetoencephalography study}, author = {Lauren R Godier and Jessica C Scaife and Sven Braeutigam and Rebecca J Park}, doi = {10.1155/2016/1795901}, year = {2016}, date = {2016-01-01}, journal = {Psychiatry Journal}, volume = {2016}, pages = {1--13}, abstract = {Neuroimaging studies in Anorexia Nervosa (AN) have shown increased activation in reward and cognitive control regions in response to food, and a behavioral attentional bias (AB) towards food stimuli is reported. This study aimed to further investigate the neural processing of food using magnetoencephalography (MEG). Participants were 13 females with restricting-type AN, 14 females recovered from restricting-type AN, and 15 female healthy controls. MEG data was acquired whilst participants viewed high- and low-calorie food pictures. Attention was assessed with a reaction time task and eye tracking. Time-series analysis suggested increased neural activity in response to both calorie conditions in the AN groups, consistent with an early AB. Increased activity was observed at 150 ms in the current AN group. Neuronal activity at this latency was at normal level in the recovered group; however, this group exhibited enhanced activity at 320 ms after stimulus. Consistent with previous studies, analysis in source space and behavioral data suggested enhanced attention and cognitive control processes in response to food stimuli in AN. This may enable avoidance of salient food stimuli and maintenance of dietary restraint in AN. A later latency of increased activity in the recovered group may reflect a reversal of this avoidance, with source space and behavioral data indicating increased visual and cognitive processing of food stimuli.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Neuroimaging studies in Anorexia Nervosa (AN) have shown increased activation in reward and cognitive control regions in response to food, and a behavioral attentional bias (AB) towards food stimuli is reported. This study aimed to further investigate the neural processing of food using magnetoencephalography (MEG). Participants were 13 females with restricting-type AN, 14 females recovered from restricting-type AN, and 15 female healthy controls. MEG data was acquired whilst participants viewed high- and low-calorie food pictures. Attention was assessed with a reaction time task and eye tracking. Time-series analysis suggested increased neural activity in response to both calorie conditions in the AN groups, consistent with an early AB. Increased activity was observed at 150 ms in the current AN group. Neuronal activity at this latency was at normal level in the recovered group; however, this group exhibited enhanced activity at 320 ms after stimulus. Consistent with previous studies, analysis in source space and behavioral data suggested enhanced attention and cognitive control processes in response to food stimuli in AN. This may enable avoidance of salient food stimuli and maintenance of dietary restraint in AN. A later latency of increased activity in the recovered group may reflect a reversal of this avoidance, with source space and behavioral data indicating increased visual and cognitive processing of food stimuli. |
Detre A Godinez; Daniel S Lumian; Tanisha Crosby-Attipoe; Ana M Bedacarratz; Paree Zarolia; Kateri McRae Overlapping and distinct neural correlates of imitating and opposing facial movements Journal Article NeuroImage, 166 , pp. 239–246, 2018. @article{Godinez2018, title = {Overlapping and distinct neural correlates of imitating and opposing facial movements}, author = {Detre A Godinez and Daniel S Lumian and Tanisha Crosby-Attipoe and Ana M Bedacarratz and Paree Zarolia and Kateri McRae}, doi = {10.1016/j.neuroimage.2017.10.023}, year = {2018}, date = {2018-01-01}, journal = {NeuroImage}, volume = {166}, pages = {239--246}, publisher = {Elsevier Ltd}, abstract = {Previous studies have demonstrated that imitating a face can be relatively automatic and reflexive. In contrast, opposing facial expressions may require engaging flexible, cognitive control. However, few studies have examined the degree to which imitation and opposition of facial movements recruit overlapping and distinct neural regions. Furthermore, little work has examined whether opposition and imitation of facial movements differ between emotional and averted eye gaze facial expressions. This study utilized a novel task with 40 participants to compare passive viewing, imitation and opposition of emotional faces looking forward and neutral faces with averted eye gaze [(3: Look, Imitate, Oppose) x (2: Emotion, Averted Eye)]. Imitation and opposition of both types of facial movements elicited overlapping activation in frontal, premotor, superior temporal and anterior intraparietal regions. These regions are recruited during cognitive control, face processing and mirroring tasks. For both emotional and averted eye gaze photos, opposition engaged the superior frontal gyrus, superior temporal sulcus and the anterior intraparietal sulcus to a greater extent compared to imitation. Finally, stimulus type and instruction interacted, such that for the eye gaze condition only, greater activation was observed in the dorsal anterior cingulate (dACC) during opposition compared to imitation, while no significant dACC differences were observed for the emotional expression conditions, which instead showed significantly greater activation in the middle and frontal pole. Overall these results showed significant overlap between imitation and opposition, as well as increased activation of these regions to generate an opposing facial movement relative to imitating.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Previous studies have demonstrated that imitating a face can be relatively automatic and reflexive. In contrast, opposing facial expressions may require engaging flexible, cognitive control. However, few studies have examined the degree to which imitation and opposition of facial movements recruit overlapping and distinct neural regions. Furthermore, little work has examined whether opposition and imitation of facial movements differ between emotional and averted eye gaze facial expressions. This study utilized a novel task with 40 participants to compare passive viewing, imitation and opposition of emotional faces looking forward and neutral faces with averted eye gaze [(3: Look, Imitate, Oppose) x (2: Emotion, Averted Eye)]. Imitation and opposition of both types of facial movements elicited overlapping activation in frontal, premotor, superior temporal and anterior intraparietal regions. These regions are recruited during cognitive control, face processing and mirroring tasks. For both emotional and averted eye gaze photos, opposition engaged the superior frontal gyrus, superior temporal sulcus and the anterior intraparietal sulcus to a greater extent compared to imitation. Finally, stimulus type and instruction interacted, such that for the eye gaze condition only, greater activation was observed in the dorsal anterior cingulate (dACC) during opposition compared to imitation, while no significant dACC differences were observed for the emotional expression conditions, which instead showed significantly greater activation in the middle and frontal pole. Overall these results showed significant overlap between imitation and opposition, as well as increased activation of these regions to generate an opposing facial movement relative to imitating. |
Jesse Gomez; Alexis Drain; Brianna Jeska; Vaidehi S Natu; Michael Barnett; Kalanit Grill-Spector Development of population receptive fields in the lateral visual stream improves spatial coding amid stable structural-functional coupling Journal Article NeuroImage, 188 , pp. 59–69, 2019. @article{Gomez2019, title = {Development of population receptive fields in the lateral visual stream improves spatial coding amid stable structural-functional coupling}, author = {Jesse Gomez and Alexis Drain and Brianna Jeska and Vaidehi S Natu and Michael Barnett and Kalanit Grill-Spector}, doi = {10.1016/j.neuroimage.2018.11.056}, year = {2019}, date = {2019-01-01}, journal = {NeuroImage}, volume = {188}, pages = {59--69}, publisher = {Elsevier Inc.}, abstract = {Human visual cortex encompasses more than a dozen visual field maps across three major processing streams. One of these streams is the lateral visual stream, which extends from V1 to lateral-occipital (LO) and temporal-occipital (TO) visual field maps and plays a prominent role in shape as well as motion perception. However, it is unknown if and how population receptive fields (pRFs) in the lateral visual stream develop from childhood to adulthood, and what impact this development may have on spatial coding. Here, we used functional magnetic resonance imaging and pRF modeling in school-age children and adults to investigate the development of the lateral visual stream. Our data reveal four main findings: 1) The topographic organization of eccentricity and polar angle maps of the lateral stream is stable after age five. 2) In both age groups there is a reliable relationship between eccentricity map transitions and cortical folding: the middle occipital gyrus predicts the transition between the peripheral representation of LO and TO maps. 3) pRFs in LO and TO maps undergo differential development from childhood to adulthood, resulting in increasing coverage of the central visual field in LO and of the peripheral visual field in TO. 4) Model-based decoding shows that the consequence of pRF and visual field coverage development is improved spatial decoding from LO and TO distributed responses in adults vs. children. Together, these results explicate both the development and topography of the lateral visual stream. Our data show that the general structural-functional organization is laid out early in development, but fine-scale properties, such as pRF distribution across the visual field and consequently, spatial precision, become fine-tuned across childhood development. These findings advance understanding of the development of the human visual system from childhood to adulthood and provide an essential foundation for understanding developmental deficits.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Human visual cortex encompasses more than a dozen visual field maps across three major processing streams. One of these streams is the lateral visual stream, which extends from V1 to lateral-occipital (LO) and temporal-occipital (TO) visual field maps and plays a prominent role in shape as well as motion perception. However, it is unknown if and how population receptive fields (pRFs) in the lateral visual stream develop from childhood to adulthood, and what impact this development may have on spatial coding. Here, we used functional magnetic resonance imaging and pRF modeling in school-age children and adults to investigate the development of the lateral visual stream. Our data reveal four main findings: 1) The topographic organization of eccentricity and polar angle maps of the lateral stream is stable after age five. 2) In both age groups there is a reliable relationship between eccentricity map transitions and cortical folding: the middle occipital gyrus predicts the transition between the peripheral representation of LO and TO maps. 3) pRFs in LO and TO maps undergo differential development from childhood to adulthood, resulting in increasing coverage of the central visual field in LO and of the peripheral visual field in TO. 4) Model-based decoding shows that the consequence of pRF and visual field coverage development is improved spatial decoding from LO and TO distributed responses in adults vs. children. Together, these results explicate both the development and topography of the lateral visual stream. Our data show that the general structural-functional organization is laid out early in development, but fine-scale properties, such as pRF distribution across the visual field and consequently, spatial precision, become fine-tuned across childhood development. These findings advance understanding of the development of the human visual system from childhood to adulthood and provide an essential foundation for understanding developmental deficits. |
Mengyuan Gong; Taosheng Liu Continuous and discrete representations of feature-based attentional priority in human frontoparietal network Journal Article Cognitive Neuroscience, 11 (1-2), pp. 47–59, 2020. @article{Gong2020, title = {Continuous and discrete representations of feature-based attentional priority in human frontoparietal network}, author = {Mengyuan Gong and Taosheng Liu}, doi = {10.1080/17588928.2019.1601074}, year = {2020}, date = {2020-01-01}, journal = {Cognitive Neuroscience}, volume = {11}, number = {1-2}, pages = {47--59}, publisher = {Routledge}, abstract = {Previous studies suggest that human frontoparietal network represents feature-based attentional priority, yet the precise nature of the priority signals remains unclear. Here, we examined whether priority signals vary continuously or discretely as a function of feature similarity. In an fMRI experiment, we presented two superimposed dot fields moving along two linear directions (leftward and rightward) while varying the angular separation between the two directions. Subjects were cued to attend to one of the two dot fields and respond to a possible speed-up in the cued direction. We used multivariate analysis to evaluate how priority representation of the attended direction changes with feature similarity. We found that in early visual areas as well as posterior intraparietal sulcus and inferior frontal junction, the patterns of neural activity became more different as the feature similarity decreased, indicating a continuous representation of the attended feature. In contrast, patterns of neural activity in anterior intraparietal sulcus and frontal eye field remained invariant to changes in feature similarity, indicating a discrete representation of the attended feature. Such distinct neural coding of attentional priority across the frontoparietal network may make complementary contributions to enable flexible attentional control.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Previous studies suggest that human frontoparietal network represents feature-based attentional priority, yet the precise nature of the priority signals remains unclear. Here, we examined whether priority signals vary continuously or discretely as a function of feature similarity. In an fMRI experiment, we presented two superimposed dot fields moving along two linear directions (leftward and rightward) while varying the angular separation between the two directions. Subjects were cued to attend to one of the two dot fields and respond to a possible speed-up in the cued direction. We used multivariate analysis to evaluate how priority representation of the attended direction changes with feature similarity. We found that in early visual areas as well as posterior intraparietal sulcus and inferior frontal junction, the patterns of neural activity became more different as the feature similarity decreased, indicating a continuous representation of the attended feature. In contrast, patterns of neural activity in anterior intraparietal sulcus and frontal eye field remained invariant to changes in feature similarity, indicating a discrete representation of the attended feature. Such distinct neural coding of attentional priority across the frontoparietal network may make complementary contributions to enable flexible attentional control. |
Claudia C Gonzalez; Jac Billington; Melanie R Burke The involvement of the fronto-parietal brain network in oculomotor sequence learning using fMRI Journal Article Neuropsychologia, 87 , pp. 1–11, 2016. @article{Gonzalez2016a, title = {The involvement of the fronto-parietal brain network in oculomotor sequence learning using fMRI}, author = {Claudia C Gonzalez and Jac Billington and Melanie R Burke}, doi = {10.1016/j.neuropsychologia.2016.04.021}, year = {2016}, date = {2016-01-01}, journal = {Neuropsychologia}, volume = {87}, pages = {1--11}, publisher = {Elsevier}, abstract = {The basis of motor learning involves decomposing complete actions into a series of predictive individual components that form the whole. The present fMRI study investigated the areas of the human brain important for oculomotor short-term learning, by using a novel sequence learning paradigm that is equivalent in visual and temporal properties for both saccades and pursuit, enabling more direct comparisons between the oculomotor subsystems. In contrast with previous studies that have implemented a series of discrete ramps to observe predictive behaviour as evidence for learning, we presented a continuous sequence of interlinked components that better represents sequences of actions. We implemented both a classic univariate fMRI analysis, followed by a further multivariate pattern analysis (MVPA) within a priori regions of interest, to investigate oculomotor sequence learning in the brain and to determine whether these mechanisms overlap in pursuit and saccades as part of a higher order learning network. This study has uniquely identified an equivalent frontal-parietal network (dorsolateral prefrontal cortex, frontal eye fields and posterior parietal cortex) in both saccades and pursuit sequence learning. In addition, this is the first study to investigate oculomotor sequence learning during fMRI brain imaging, and makes significant contributions to understanding the role of the dorsal networks in motor learning.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The basis of motor learning involves decomposing complete actions into a series of predictive individual components that form the whole. The present fMRI study investigated the areas of the human brain important for oculomotor short-term learning, by using a novel sequence learning paradigm that is equivalent in visual and temporal properties for both saccades and pursuit, enabling more direct comparisons between the oculomotor subsystems. In contrast with previous studies that have implemented a series of discrete ramps to observe predictive behaviour as evidence for learning, we presented a continuous sequence of interlinked components that better represents sequences of actions. We implemented both a classic univariate fMRI analysis, followed by a further multivariate pattern analysis (MVPA) within a priori regions of interest, to investigate oculomotor sequence learning in the brain and to determine whether these mechanisms overlap in pursuit and saccades as part of a higher order learning network. This study has uniquely identified an equivalent frontal-parietal network (dorsolateral prefrontal cortex, frontal eye fields and posterior parietal cortex) in both saccades and pursuit sequence learning. In addition, this is the first study to investigate oculomotor sequence learning during fMRI brain imaging, and makes significant contributions to understanding the role of the dorsal networks in motor learning. |
Jessica E Goold; Wonil Choi; John M Henderson Cortical control of eye movements in natural reading: Evidence from MVPA Journal Article Experimental Brain Research, 237 (12), pp. 3099–3107, 2019. @article{Goold2019, title = {Cortical control of eye movements in natural reading: Evidence from MVPA}, author = {Jessica E Goold and Wonil Choi and John M Henderson}, doi = {10.1007/s00221-019-05655-3}, year = {2019}, date = {2019-09-01}, journal = {Experimental Brain Research}, volume = {237}, number = {12}, pages = {3099--3107}, abstract = {Language comprehension during reading requires fine-grained management of saccadic eye movements. A critical question, therefore, is how the brain controls eye movements in reading. Neural correlates of simple eye movements have been found in multiple cortical regions, but little is known about how this network operates in reading. To investigate this question in the present study, participants were presented with normal text, pseudo-word text, and consonant string text in a magnetic resonance imaging (MRI) scanner with eyetracking. Participants read naturally in the normal text condition and moved their eyes “as if they were reading” in the other conditions. Multi-voxel pattern analysis was used to analyze the fMRI signal in the oculomotor network. We found that activation patterns in a subset of network regions differentiated between stimulus types. These results suggest that the oculomotor network reflects more than simple saccade generation and are consistent with the hypothesis that specific network areas interface with cognitive systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Language comprehension during reading requires fine-grained management of saccadic eye movements. A critical question, therefore, is how the brain controls eye movements in reading. Neural correlates of simple eye movements have been found in multiple cortical regions, but little is known about how this network operates in reading. To investigate this question in the present study, participants were presented with normal text, pseudo-word text, and consonant string text in a magnetic resonance imaging (MRI) scanner with eyetracking. Participants read naturally in the normal text condition and moved their eyes “as if they were reading” in the other conditions. Multi-voxel pattern analysis was used to analyze the fMRI signal in the oculomotor network. We found that activation patterns in a subset of network regions differentiated between stimulus types. These results suggest that the oculomotor network reflects more than simple saccade generation and are consistent with the hypothesis that specific network areas interface with cognitive systems. |
Evan M Gordon; Timothy O Laumann; Adrian W Gilmore; Dillan J Newbold; Deanna J Greene; Jeffrey J Berg; Mario Ortega; Catherine Hoyt-Drazen; Caterina Gratton; Haoxin Sun; Jacqueline M Hampton; Rebecca S Coalson; Annie L Nguyen; Kathleen B McDermott; Joshua S Shimony; Abraham Z Snyder; Bradley L Schlaggar; Steven E Petersen; Steven M Nelson; Nico U F Dosenbach Precision functional mapping of individual human brains Journal Article Neuron, 95 (4), pp. 791–807, 2017. @article{Gordon2017, title = {Precision functional mapping of individual human brains}, author = {Evan M Gordon and Timothy O Laumann and Adrian W Gilmore and Dillan J Newbold and Deanna J Greene and Jeffrey J Berg and Mario Ortega and Catherine Hoyt-Drazen and Caterina Gratton and Haoxin Sun and Jacqueline M Hampton and Rebecca S Coalson and Annie L Nguyen and Kathleen B McDermott and Joshua S Shimony and Abraham Z Snyder and Bradley L Schlaggar and Steven E Petersen and Steven M Nelson and Nico U F Dosenbach}, doi = {10.1016/j.neuron.2017.07.011}, year = {2017}, date = {2017-01-01}, journal = {Neuron}, volume = {95}, number = {4}, pages = {791--807}, publisher = {Elsevier Inc.}, abstract = {Human functional MRI (fMRI) research primarily focuses on analyzing data averaged across groups, which limits the detail, specificity, and clinical utility of fMRI resting-state functional connectivity (RSFC) and task-activation maps. To push our understanding of functional brain organization to the level of individual humans, we assembled a novel MRI dataset containing 5 hr of RSFC data, 6 hr of task fMRI, multiple structural MRIs, and neuro- psychological tests from each of ten adults. Using these data, we generated ten high-fidelity, individual-specific functional connectomes. This individual-connectome approach revealed several new types of spatial and organizational variability in brain networks, including unique network features and topologies that corresponded with structural and task-derived brain features. We are releasing this highly sampled, individual-focused dataset as a resource for neuroscientists, and we propose precision individual connectomics as a model for future work examining the organization of healthy and diseased individual human brains.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Human functional MRI (fMRI) research primarily focuses on analyzing data averaged across groups, which limits the detail, specificity, and clinical utility of fMRI resting-state functional connectivity (RSFC) and task-activation maps. To push our understanding of functional brain organization to the level of individual humans, we assembled a novel MRI dataset containing 5 hr of RSFC data, 6 hr of task fMRI, multiple structural MRIs, and neuro- psychological tests from each of ten adults. Using these data, we generated ten high-fidelity, individual-specific functional connectomes. This individual-connectome approach revealed several new types of spatial and organizational variability in brain networks, including unique network features and topologies that corresponded with structural and task-derived brain features. We are releasing this highly sampled, individual-focused dataset as a resource for neuroscientists, and we propose precision individual connectomics as a model for future work examining the organization of healthy and diseased individual human brains. |
Andrea Grant; Gregory J Metzger; Pierre François Van de Moortele; Gregor Adriany; Cheryl Olman; Lin Zhang; Joseph Koopermeiners; Yiğitcan Eryaman; Margaret Koeritzer; Meredith E Adams; Thomas R Henry; Kamil Uğurbil 10.5 T MRI static field effects on human cognitive, vestibular, and physiological function Journal Article Magnetic Resonance Imaging, 73 , pp. 163–176, 2020. @article{Grant2020, title = {10.5 T MRI static field effects on human cognitive, vestibular, and physiological function}, author = {Andrea Grant and Gregory J Metzger and Pierre Fran{ç}ois {Van de Moortele} and Gregor Adriany and Cheryl Olman and Lin Zhang and Joseph Koopermeiners and Yiğitcan Eryaman and Margaret Koeritzer and Meredith E Adams and Thomas R Henry and Kamil Uğurbil}, doi = {10.1016/j.mri.2020.08.004}, year = {2020}, date = {2020-01-01}, journal = {Magnetic Resonance Imaging}, volume = {73}, pages = {163--176}, publisher = {Elsevier}, abstract = {Purpose: To perform a pilot study to quantitatively assess cognitive, vestibular, and physiological function during and after exposure to a magnetic resonance imaging (MRI) system with a static field strength of 10.5 Tesla at multiple time scales. Methods: A total of 29 subjects were exposed to a 10.5 T MRI field and underwent vestibular, cognitive, and physiological testing before, during, and after exposure; for 26 subjects, testing and exposure were repeated within 2–4 weeks of the first visit. Subjects also reported sensory perceptions after each exposure. Comparisons were made between short and long term time points in the study with respect to the parameters measured in the study; short term comparison included pre-vs-isocenter and pre-vs-post (1–24 h), while long term compared pre-exposures 2–4 weeks apart. Results: Of the 79 comparisons, 73 parameters were unchanged or had small improvements after magnet exposure. The exceptions to this included lower scores on short term (i.e. same day) executive function testing, greater isocenter spontaneous eye movement during visit 1 (relative to pre-exposure), increased number of abnormalities on videonystagmography visit 2 versus visit 1 and a mix of small increases (short term visit 2) and decreases (short term visit 1) in blood pressure. In addition, more subjects reported metallic taste at 10.5 T in comparison to similar data obtained in previous studies at 7 T and 9.4 T. Conclusion: Initial results of 10.5 T static field exposure indicate that 1) cognitive performance is not compromised at isocenter, 2) subjects experience increased eye movement at isocenter, and 3) subjects experience small changes in vital signs but no field-induced increase in blood pressure. While small but significant differences were found in some comparisons, none were identified as compromising subject safety. A modified testing protocol informed by these results was devised with the goal of permitting increased enrollment while providing continued monitoring to evaluate field effects.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Purpose: To perform a pilot study to quantitatively assess cognitive, vestibular, and physiological function during and after exposure to a magnetic resonance imaging (MRI) system with a static field strength of 10.5 Tesla at multiple time scales. Methods: A total of 29 subjects were exposed to a 10.5 T MRI field and underwent vestibular, cognitive, and physiological testing before, during, and after exposure; for 26 subjects, testing and exposure were repeated within 2–4 weeks of the first visit. Subjects also reported sensory perceptions after each exposure. Comparisons were made between short and long term time points in the study with respect to the parameters measured in the study; short term comparison included pre-vs-isocenter and pre-vs-post (1–24 h), while long term compared pre-exposures 2–4 weeks apart. Results: Of the 79 comparisons, 73 parameters were unchanged or had small improvements after magnet exposure. The exceptions to this included lower scores on short term (i.e. same day) executive function testing, greater isocenter spontaneous eye movement during visit 1 (relative to pre-exposure), increased number of abnormalities on videonystagmography visit 2 versus visit 1 and a mix of small increases (short term visit 2) and decreases (short term visit 1) in blood pressure. In addition, more subjects reported metallic taste at 10.5 T in comparison to similar data obtained in previous studies at 7 T and 9.4 T. Conclusion: Initial results of 10.5 T static field exposure indicate that 1) cognitive performance is not compromised at isocenter, 2) subjects experience increased eye movement at isocenter, and 3) subjects experience small changes in vital signs but no field-induced increase in blood pressure. While small but significant differences were found in some comparisons, none were identified as compromising subject safety. A modified testing protocol informed by these results was devised with the goal of permitting increased enrollment while providing continued monitoring to evaluate field effects. |
Tsafrir Greenberg; Joshua M Carlson; Jiook Cha; Greg Hajcak; Lilianne R Mujica-Parodi Neural reactivity tracks fear generalization gradients Journal Article Biological Psychology, 92 (1), pp. 2–8, 2013. @article{Greenberg2013, title = {Neural reactivity tracks fear generalization gradients}, author = {Tsafrir Greenberg and Joshua M Carlson and Jiook Cha and Greg Hajcak and Lilianne R Mujica-Parodi}, doi = {10.1016/j.biopsycho.2011.12.007}, year = {2013}, date = {2013-01-01}, journal = {Biological Psychology}, volume = {92}, number = {1}, pages = {2--8}, publisher = {Elsevier B.V.}, abstract = {Recent studies on fear generalization have demonstrated that fear-potentiated startle and skin conductance responses to a conditioned stimulus (CS) generalize to similar stimuli, with the strength of the fear response linked to perceptual similarity to the CS. The aim of the present study was to extend this work by examining neural correlates of fear generalization. An initial experiment (N= 8) revealed that insula reactivity tracks the conditioned fear gradient. We then replicated this effect in a larger independent sample (N= 25). Activation in the insula, anterior cingulate, right supplementary motor cortex and caudate increased reactivity as generalization stimuli (GS) were more similar to the CS, consistent with participants' overall ratings of perceived shock likelihood and pupillary response to each stimulus.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Recent studies on fear generalization have demonstrated that fear-potentiated startle and skin conductance responses to a conditioned stimulus (CS) generalize to similar stimuli, with the strength of the fear response linked to perceptual similarity to the CS. The aim of the present study was to extend this work by examining neural correlates of fear generalization. An initial experiment (N= 8) revealed that insula reactivity tracks the conditioned fear gradient. We then replicated this effect in a larger independent sample (N= 25). Activation in the insula, anterior cingulate, right supplementary motor cortex and caudate increased reactivity as generalization stimuli (GS) were more similar to the CS, consistent with participants' overall ratings of perceived shock likelihood and pupillary response to each stimulus. |
Tsafrir Greenberg; Joshua M Carlson; Jiook Cha; Greg Hajcak; Lilianne R Mujica-Parodi Ventromedial prefrontal cortex reactivity is altered in generalized anxiety disorder during fear generalization Journal Article Depression and Anxiety, 30 (3), pp. 242–250, 2013. @article{Greenberg2013a, title = {Ventromedial prefrontal cortex reactivity is altered in generalized anxiety disorder during fear generalization}, author = {Tsafrir Greenberg and Joshua M Carlson and Jiook Cha and Greg Hajcak and Lilianne R Mujica-Parodi}, doi = {10.1002/da.22016}, year = {2013}, date = {2013-01-01}, journal = {Depression and Anxiety}, volume = {30}, number = {3}, pages = {242--250}, abstract = {BACKGROUND: Fear generalization is thought to contribute to the development and maintenance of anxiety symptoms and accordingly has been the focus of recent research. Previously, we reported that in healthy individuals (N = 25) neural reactivity in the insula, anterior cingulate cortex (ACC), supplementary motor area (SMA), and caudate follow a generalization gradient with a peak response to a conditioned stimulus (CS) that declines with greater perceptual dissimilarity of generalization stimuli (GS) to the CS. In contrast, reactivity in the ventromedial prefrontal cortex (vmPFC), a region linked to fear inhibition, showed an opposite response pattern. The aim of the current study was to examine whether neural responses to fear generalization differ in generalized anxiety disorder (GAD). A second aim was to examine connectivity of primary regions engaged by the generalization task in the GAD group versus healthy group, using psychophysiological interaction analysis. METHODS: Thirty-two women diagnosed with GAD were scanned using the same generalization task as our healthy group. RESULTS: Individuals with GAD exhibited a less discriminant vmPFC response pattern suggestive of deficient recruitment of vmPFC during fear inhibition. Across participants, there was enhanced anterior insula (aINS) coupling with the posterior insula, ACC, SMA, and amygdala during presentation of the CS, consistent with a modulatory role for the aINS in the execution of fear responses. CONCLUSIONS: These findings suggest that deficits in fear regulation, rather than in the excitatory response itself, are more critical to the pathophysiology of GAD in the context of fear generalization.}, keywords = {}, pubstate = {published}, tppubtype = {article} } BACKGROUND: Fear generalization is thought to contribute to the development and maintenance of anxiety symptoms and accordingly has been the focus of recent research. Previously, we reported that in healthy individuals (N = 25) neural reactivity in the insula, anterior cingulate cortex (ACC), supplementary motor area (SMA), and caudate follow a generalization gradient with a peak response to a conditioned stimulus (CS) that declines with greater perceptual dissimilarity of generalization stimuli (GS) to the CS. In contrast, reactivity in the ventromedial prefrontal cortex (vmPFC), a region linked to fear inhibition, showed an opposite response pattern. The aim of the current study was to examine whether neural responses to fear generalization differ in generalized anxiety disorder (GAD). A second aim was to examine connectivity of primary regions engaged by the generalization task in the GAD group versus healthy group, using psychophysiological interaction analysis. METHODS: Thirty-two women diagnosed with GAD were scanned using the same generalization task as our healthy group. RESULTS: Individuals with GAD exhibited a less discriminant vmPFC response pattern suggestive of deficient recruitment of vmPFC during fear inhibition. Across participants, there was enhanced anterior insula (aINS) coupling with the posterior insula, ACC, SMA, and amygdala during presentation of the CS, consistent with a modulatory role for the aINS in the execution of fear responses. CONCLUSIONS: These findings suggest that deficits in fear regulation, rather than in the excitatory response itself, are more critical to the pathophysiology of GAD in the context of fear generalization. |
Sarah Gregory; Marco Fusca; Geraint Rees; Samuel D Schwarzkopf; Gareth Barnes Gamma frequency and the spatial tuning of primary visual cortex Journal Article PLoS ONE, 11 (6), pp. 1–12, 2016. @article{Gregory2016a, title = {Gamma frequency and the spatial tuning of primary visual cortex}, author = {Sarah Gregory and Marco Fusca and Geraint Rees and Samuel D Schwarzkopf and Gareth Barnes}, doi = {10.1371/journal.pone.0157374}, year = {2016}, date = {2016-01-01}, journal = {PLoS ONE}, volume = {11}, number = {6}, pages = {1--12}, abstract = {Visual stimulation produces oscillatory gamma responses in human primary visual cortex (V1) that also relate to visual perception. We have shown previously that peak gamma frequency positively correlates with central V1 cortical surface area. We hypothesized that people with larger V1 would have smaller receptive fields and that receptive field size, not V1 are, might explain this relationship. Here we set out to test this hypothesis directly by investigating the relationship between fMRI estimated population receptive field (pRF) size and gamma frequency in V1. We stimulated both the near-centre and periphery of the visual field using both large and small stimuli in each location and replicated our previous finding of a positive correlation between V1 surface area and peak gamma frequency. Counter to our expectation, we found that between participants V1 size (and not pRF size) accounted for most of the variability in gamma frequency. Within-participants we found that gamma frequency increased, rather than decreased, with stimulus eccentricity directly contradicting our initial hypothesis.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Visual stimulation produces oscillatory gamma responses in human primary visual cortex (V1) that also relate to visual perception. We have shown previously that peak gamma frequency positively correlates with central V1 cortical surface area. We hypothesized that people with larger V1 would have smaller receptive fields and that receptive field size, not V1 are, might explain this relationship. Here we set out to test this hypothesis directly by investigating the relationship between fMRI estimated population receptive field (pRF) size and gamma frequency in V1. We stimulated both the near-centre and periphery of the visual field using both large and small stimuli in each location and replicated our previous finding of a positive correlation between V1 surface area and peak gamma frequency. Counter to our expectation, we found that between participants V1 size (and not pRF size) accounted for most of the variability in gamma frequency. Within-participants we found that gamma frequency increased, rather than decreased, with stimulus eccentricity directly contradicting our initial hypothesis. |
Joseph C Griffis; Abdurahman S Elkhetali; Ryan J Vaden; Kristina M Visscher Distinct effects of trial-driven and task set-related control in primary visual cortex Journal Article NeuroImage, 120 , pp. 285–297, 2015. @article{Griffis2015, title = {Distinct effects of trial-driven and task set-related control in primary visual cortex}, author = {Joseph C Griffis and Abdurahman S Elkhetali and Ryan J Vaden and Kristina M Visscher}, doi = {10.1007/s10995-015-1800-4.Alcohol}, year = {2015}, date = {2015-01-01}, journal = {NeuroImage}, volume = {120}, pages = {285--297}, abstract = {Task sets are task-specific configurations of cognitive processes that facilitate task-appropriate reactions to stimuli. While it is established that the trial-by-trial deployment of visual attention to expected stimuli influences neural responses in primary visual cortex (V1) in a retinotopically specific manner, it is not clear whether the mechanisms that help maintain a task set over many trials also operate with similar retinotopic specificity. Here, we address this question by using BOLD fMRI to characterize how portions of V1 that are specialized for different eccentricities respond during distinct components of an attention-demanding discrimination task: cue-driven preparation for a trial, trial-driven processing, task-initiation at the beginning of a block of trials, and task-maintenance throughout a block of trials. Tasks required either unimodal attention to an auditory or a visual stimulus or selective intermodal attention to the visual or auditory component of simultaneously presented visual and auditory stimuli. We found that while the retinotopic patterns of trial-driven and cue-driven activity depended on the attended stimulus, the retinotopic patterns of task-initiation and task-maintenance activity did not. Further, only the retinotopic patterns of trial-driven activity were found to depend on the presence of inter-modal distraction. Participants who performed well on the intermodal selective attention tasks showed strong task-specific modulations of both trial-driven and task-maintenance activity. Importantly, task-related modulations of trial-driven and task-maintenance activity were in opposite directions. Together, these results confirm that there are (at least) two different processes for top-down control of V1: One, working trial-by-trial, differently modulates activity across different eccentricity sectors - portions of V1 corresponding to different visual eccentricities. The second process works across longer epochs of task performance, and does not differ among eccentricity sectors. These results are discussed in the context of previous literature examining top-down control of visual cortical areas.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Task sets are task-specific configurations of cognitive processes that facilitate task-appropriate reactions to stimuli. While it is established that the trial-by-trial deployment of visual attention to expected stimuli influences neural responses in primary visual cortex (V1) in a retinotopically specific manner, it is not clear whether the mechanisms that help maintain a task set over many trials also operate with similar retinotopic specificity. Here, we address this question by using BOLD fMRI to characterize how portions of V1 that are specialized for different eccentricities respond during distinct components of an attention-demanding discrimination task: cue-driven preparation for a trial, trial-driven processing, task-initiation at the beginning of a block of trials, and task-maintenance throughout a block of trials. Tasks required either unimodal attention to an auditory or a visual stimulus or selective intermodal attention to the visual or auditory component of simultaneously presented visual and auditory stimuli. We found that while the retinotopic patterns of trial-driven and cue-driven activity depended on the attended stimulus, the retinotopic patterns of task-initiation and task-maintenance activity did not. Further, only the retinotopic patterns of trial-driven activity were found to depend on the presence of inter-modal distraction. Participants who performed well on the intermodal selective attention tasks showed strong task-specific modulations of both trial-driven and task-maintenance activity. Importantly, task-related modulations of trial-driven and task-maintenance activity were in opposite directions. Together, these results confirm that there are (at least) two different processes for top-down control of V1: One, working trial-by-trial, differently modulates activity across different eccentricity sectors - portions of V1 corresponding to different visual eccentricities. The second process works across longer epochs of task performance, and does not differ among eccentricity sectors. These results are discussed in the context of previous literature examining top-down control of visual cortical areas. |
Joseph C Griffis; Abdurahman S Elkhetali; Wesley K Burge; Richard H Chen; Anthony D Bowman; Jerzy P Szaflarski; Kristina M Visscher Retinotopic patterns of functional connectivity between V1 and large-scale brain networks during resting fixation Journal Article NeuroImage, 146 , pp. 1071–1083, 2017. @article{Griffis2017, title = {Retinotopic patterns of functional connectivity between V1 and large-scale brain networks during resting fixation}, author = {Joseph C Griffis and Abdurahman S Elkhetali and Wesley K Burge and Richard H Chen and Anthony D Bowman and Jerzy P Szaflarski and Kristina M Visscher}, doi = {10.1016/j.neuroimage.2016.08.035}, year = {2017}, date = {2017-01-01}, journal = {NeuroImage}, volume = {146}, pages = {1071--1083}, abstract = {Psychophysical and neurobiological evidence suggests that central and peripheral vision are specialized for different functions. This specialization of function might be expected to lead to differences in the large-scale functional interactions of early cortical areas that represent central and peripheral visual space. Here, we characterize differences in whole-brain functional connectivity among sectors in primary visual cortex (V1) corresponding to central, near-peripheral, and far-peripheral vision during resting fixation. Importantly, our analyses reveal that eccentricity sectors in V1 have different functional connectivity with non-visual areas associated with large-scale brain networks. Regions associated with the fronto-parietal control network are most strongly connected with central sectors of V1, regions associated with the cingulo-opercular control network are most strongly connected with near-peripheral sectors of V1, and regions associated with the default mode and auditory networks are most strongly connected with far-peripheral sectors of V1. Additional analyses suggest that similar patterns are present during eyes-closed rest. These results suggest that different types of visual information may be prioritized by large-scale brain networks with distinct functional profiles, and provide insights into how the small-scale functional specialization within early visual regions such as V1 relates to the large-scale organization of functionally distinct whole-brain networks.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Psychophysical and neurobiological evidence suggests that central and peripheral vision are specialized for different functions. This specialization of function might be expected to lead to differences in the large-scale functional interactions of early cortical areas that represent central and peripheral visual space. Here, we characterize differences in whole-brain functional connectivity among sectors in primary visual cortex (V1) corresponding to central, near-peripheral, and far-peripheral vision during resting fixation. Importantly, our analyses reveal that eccentricity sectors in V1 have different functional connectivity with non-visual areas associated with large-scale brain networks. Regions associated with the fronto-parietal control network are most strongly connected with central sectors of V1, regions associated with the cingulo-opercular control network are most strongly connected with near-peripheral sectors of V1, and regions associated with the default mode and auditory networks are most strongly connected with far-peripheral sectors of V1. Additional analyses suggest that similar patterns are present during eyes-closed rest. These results suggest that different types of visual information may be prioritized by large-scale brain networks with distinct functional profiles, and provide insights into how the small-scale functional specialization within early visual regions such as V1 relates to the large-scale organization of functionally distinct whole-brain networks. |
Joseph C Griffis; Nicholas V Metcalf; Maurizio Corbetta; Gordon L Shulman NeuroImage, 210 , pp. 1–12, 2020. @article{Griffis2020, title = {Damage to the shortest structural paths between brain regions is associated with disruptions of resting-state functional connectivity after stroke}, author = {Joseph C Griffis and Nicholas V Metcalf and Maurizio Corbetta and Gordon L Shulman}, doi = {10.1016/j.neuroimage.2020.116589}, year = {2020}, date = {2020-01-01}, journal = {NeuroImage}, volume = {210}, pages = {1--12}, abstract = {Focal brain lesions disrupt resting-state functional connectivity, but the underlying structural mechanisms are unclear. Here, we examined the direct and indirect effects of structural disconnections on resting-state functional connectivity in a large sample of sub-acute stroke patients with heterogeneous brain lesions. We estimated the impact of each patient's lesion on the structural connectome by embedding the lesion in a diffusion MRI streamline tractography atlas constructed using data from healthy individuals. We defined direct disconnections as the loss of direct structural connections between two regions, and indirect disconnections as increases in the shortest structural path length between two regions that lack direct structural connections. We then tested the hypothesis that functional connectivity disruptions would be more severe for disconnected regions than for regions with spared connections. On average, nearly 20% of all region pairs were estimated to be either directly or indirectly disconnected by the lesions in our sample, and extensive disconnections were associated primarily with damage to deep white matter locations. Importantly, both directly and indirectly disconnected region pairs showed more severe functional connectivity disruptions than region pairs with spared direct and indirect connections, respectively, although functional connectivity disruptions tended to be most severe between region pairs that sustained direct structural disconnections. Together, these results emphasize the widespread impacts of focal brain lesions on the structural connectome and show that these impacts are reflected by disruptions of the functional connectome. Further, they indicate that in addition to direct structural disconnections, lesion-induced increases in the structural shortest path lengths between indirectly structurally connected region pairs provide information about the remote functional disruptions caused by focal brain lesions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Focal brain lesions disrupt resting-state functional connectivity, but the underlying structural mechanisms are unclear. Here, we examined the direct and indirect effects of structural disconnections on resting-state functional connectivity in a large sample of sub-acute stroke patients with heterogeneous brain lesions. We estimated the impact of each patient's lesion on the structural connectome by embedding the lesion in a diffusion MRI streamline tractography atlas constructed using data from healthy individuals. We defined direct disconnections as the loss of direct structural connections between two regions, and indirect disconnections as increases in the shortest structural path length between two regions that lack direct structural connections. We then tested the hypothesis that functional connectivity disruptions would be more severe for disconnected regions than for regions with spared connections. On average, nearly 20% of all region pairs were estimated to be either directly or indirectly disconnected by the lesions in our sample, and extensive disconnections were associated primarily with damage to deep white matter locations. Importantly, both directly and indirectly disconnected region pairs showed more severe functional connectivity disruptions than region pairs with spared direct and indirect connections, respectively, although functional connectivity disruptions tended to be most severe between region pairs that sustained direct structural disconnections. Together, these results emphasize the widespread impacts of focal brain lesions on the structural connectome and show that these impacts are reflected by disruptions of the functional connectome. Further, they indicate that in addition to direct structural disconnections, lesion-induced increases in the structural shortest path lengths between indirectly structurally connected region pairs provide information about the remote functional disruptions caused by focal brain lesions. |
Josephine M Groot; Nya M Boayue; Gábor Csifcsák; Wouter Boekel; René Huster; Birte U Forstmann; Matthias Mittner Probing the neural signature of mind wandering with simultaneous fMRI-EEG and pupillometry Journal Article NeuroImage, 224 , pp. 1–10, 2021. @article{Groot2021, title = {Probing the neural signature of mind wandering with simultaneous fMRI-EEG and pupillometry}, author = {Josephine M Groot and Nya M Boayue and Gábor Csifcsák and Wouter Boekel and René Huster and Birte U Forstmann and Matthias Mittner}, doi = {10.1016/j.neuroimage.2020.117412}, year = {2021}, date = {2021-01-01}, journal = {NeuroImage}, volume = {224}, pages = {1--10}, publisher = {Elsevier Inc.}, abstract = {Mind wandering reflects the shift in attentional focus from task-related cognition driven by external stimuli toward self-generated and internally-oriented thought processes. Although such task-unrelated thoughts (TUTs) are pervasive and detrimental to task performance, their underlying neural mechanisms are only modestly understood. To investigate TUTs with high spatial and temporal precision, we simultaneously measured fMRI, EEG, and pupillometry in healthy adults while they performed a sustained attention task with experience sampling probes. Features of interest were extracted from each modality at the single-trial level and fed to a support vector machine that was trained on the probe responses. Compared to task-focused attention, the neural signature of TUTs was characterized by weaker activity in the default mode network but elevated activity in its anticorrelated network, stronger functional coupling between these networks, widespread increase in alpha, theta, delta, but not beta, frequency power, predominantly reduced amplitudes of late, but not early, event-related potentials, and larger baseline pupil size. Particularly, information contained in dynamic interactions between large-scale cortical networks was predictive of transient changes in attentional focus above other modalities. Together, our results provide insight into the spatiotemporal dynamics of TUTs and the neural markers that may facilitate their detection.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Mind wandering reflects the shift in attentional focus from task-related cognition driven by external stimuli toward self-generated and internally-oriented thought processes. Although such task-unrelated thoughts (TUTs) are pervasive and detrimental to task performance, their underlying neural mechanisms are only modestly understood. To investigate TUTs with high spatial and temporal precision, we simultaneously measured fMRI, EEG, and pupillometry in healthy adults while they performed a sustained attention task with experience sampling probes. Features of interest were extracted from each modality at the single-trial level and fed to a support vector machine that was trained on the probe responses. Compared to task-focused attention, the neural signature of TUTs was characterized by weaker activity in the default mode network but elevated activity in its anticorrelated network, stronger functional coupling between these networks, widespread increase in alpha, theta, delta, but not beta, frequency power, predominantly reduced amplitudes of late, but not early, event-related potentials, and larger baseline pupil size. Particularly, information contained in dynamic interactions between large-scale cortical networks was predictive of transient changes in attentional focus above other modalities. Together, our results provide insight into the spatiotemporal dynamics of TUTs and the neural markers that may facilitate their detection. |
Marcus Grueschow; Birgit Kleim; Christian C Ruff Role of the locus coeruleus arousal system in cognitive control Journal Article Journal of Neuroendocrinology, 32 , pp. 1–11, 2020. @article{Grueschow2020, title = {Role of the locus coeruleus arousal system in cognitive control}, author = {Marcus Grueschow and Birgit Kleim and Christian C Ruff}, doi = {10.1111/jne.12890}, year = {2020}, date = {2020-01-01}, journal = {Journal of Neuroendocrinology}, volume = {32}, pages = {1--11}, abstract = {Cognitive control lies at the core of human adaptive behaviour. Humans vary substantially in their ability to execute cognitive control with respect to optimally facing environmental challenges, although the neural origins of this heterogeneity are currently not well understood. Recent theoretical frameworks implicate the locus coeruleus noradrenergic arousal system (LC-NE) in that process. Invasive neurophysiological work in rodents has shown that the LC-NE is an important homeostatic control centre of the body. LC-NE innervates the entire neocortex and has particularly strong connections with the cingulate gyrus. In the present study, using a response conflict task, functional magnetic resonance imaging and concurrent pupil dilation measures (a proxy for LC-NE firing), we provide empirical evidence for a decisive role of the LC-NE in cognitive control in humans. We show that the level of individual behavioural adjustment in cognitive control relates to the level of functional coupling between LC-NE and the dorsomedial prefrontal cortex, as well as dorsolateral prefrontal cortex. Moreover, we show that the pupil is substantially more dilated during conflict trials requiring behavioural adjustment than during no conflict trials. In addition, we explore a potential relationship between pupil dilation and neural activity during choice conflict adjustments. Our data provide novel insight into arousal-related influences on cognitive control and suggest pupil dilation as a potential external marker for endogenous neural processes involved in optimising behavioural control. Our results may also be clinically relevant for a variety of pathologies where cognitive control is compromised, such as anxiety, depression, addiction and post-traumatic stress disorder.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Cognitive control lies at the core of human adaptive behaviour. Humans vary substantially in their ability to execute cognitive control with respect to optimally facing environmental challenges, although the neural origins of this heterogeneity are currently not well understood. Recent theoretical frameworks implicate the locus coeruleus noradrenergic arousal system (LC-NE) in that process. Invasive neurophysiological work in rodents has shown that the LC-NE is an important homeostatic control centre of the body. LC-NE innervates the entire neocortex and has particularly strong connections with the cingulate gyrus. In the present study, using a response conflict task, functional magnetic resonance imaging and concurrent pupil dilation measures (a proxy for LC-NE firing), we provide empirical evidence for a decisive role of the LC-NE in cognitive control in humans. We show that the level of individual behavioural adjustment in cognitive control relates to the level of functional coupling between LC-NE and the dorsomedial prefrontal cortex, as well as dorsolateral prefrontal cortex. Moreover, we show that the pupil is substantially more dilated during conflict trials requiring behavioural adjustment than during no conflict trials. In addition, we explore a potential relationship between pupil dilation and neural activity during choice conflict adjustments. Our data provide novel insight into arousal-related influences on cognitive control and suggest pupil dilation as a potential external marker for endogenous neural processes involved in optimising behavioural control. Our results may also be clinically relevant for a variety of pathologies where cognitive control is compromised, such as anxiety, depression, addiction and post-traumatic stress disorder. |
Scott A Guerin; Clifford A Robbins; Adrian W Gilmore; Daniel L Schacter Retrieval failure contributes to gist-based false recognition Journal Article Journal of Memory and Language, 66 (1), pp. 68–78, 2012. @article{Guerin2012, title = {Retrieval failure contributes to gist-based false recognition}, author = {Scott A Guerin and Clifford A Robbins and Adrian W Gilmore and Daniel L Schacter}, doi = {10.1016/j.jml.2011.07.002}, year = {2012}, date = {2012-01-01}, journal = {Journal of Memory and Language}, volume = {66}, number = {1}, pages = {68--78}, publisher = {Elsevier Inc.}, abstract = {People often falsely recognize items that are similar to previously encountered items. This robust memory error is referred to as gist-based false recognition. A widely held view is that this error occurs because the details fade rapidly from our memory. Contrary to this view, an initial experiment revealed that, following the same encoding conditions that produce high rates of gist-based false recognition, participants overwhelmingly chose the correct target rather than its related foil when given the option to do so. A second experiment showed that this result is due to increased access to stored details provided by reinstatement of the originally encoded photograph, rather than to increased attention to the details. Collectively, these results suggest that details needed for accurate recognition are, to a large extent, still stored in memory and that a critical factor determining whether false recognition will occur is whether these details can be accessed during retrieval.}, keywords = {}, pubstate = {published}, tppubtype = {article} } People often falsely recognize items that are similar to previously encountered items. This robust memory error is referred to as gist-based false recognition. A widely held view is that this error occurs because the details fade rapidly from our memory. Contrary to this view, an initial experiment revealed that, following the same encoding conditions that produce high rates of gist-based false recognition, participants overwhelmingly chose the correct target rather than its related foil when given the option to do so. A second experiment showed that this result is due to increased access to stored details provided by reinstatement of the originally encoded photograph, rather than to increased attention to the details. Collectively, these results suggest that details needed for accurate recognition are, to a large extent, still stored in memory and that a critical factor determining whether false recognition will occur is whether these details can be accessed during retrieval. |
Alain Guillaume; Jason R Fuller; Riju Srimal; Clayton E Curtis Cortico-cerebellar network involved in saccade adaptation Journal Article Journal of Neurophysiology, 120 (5), pp. 2583–2594, 2018. @article{Guillaume2018, title = {Cortico-cerebellar network involved in saccade adaptation}, author = {Alain Guillaume and Jason R Fuller and Riju Srimal and Clayton E Curtis}, doi = {10.1152/jn.00392.2018}, year = {2018}, date = {2018-01-01}, journal = {Journal of Neurophysiology}, volume = {120}, number = {5}, pages = {2583--2594}, abstract = {Saccade adaptation is the learning process that en- sures that vision and saccades remain calibrated. The central nervous system network involved in these adaptive processes remains unclear because of difficulties in isolating the learning process from the correlated visual and motor processes. Here we imaged the human brain during a novel saccade adaptation paradigm that allowed us to isolate neural signals involved in learning independent of the changes in the amplitude of corrective saccades usually correlated with adap- tation. We show that the changes in activation in the ipsiversive cerebellar vermis that track adaptation are not driven by the changes in corrective saccades and thus provide critical supporting evidence for previous findings. Similarly, we find that activation in the dorso- medial wall of the contraversive precuneus mirrors the pattern found in the cerebellum. Finally, we identify dorsolateral and dorsomedial cortical areas in the frontal and parietal lobes that encode the retinal errors following inaccurate saccades used to drive recalibration. To- gether, these data identify a distributed network of cerebellar and cortical areas and their specific roles in oculomotor learning.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Saccade adaptation is the learning process that en- sures that vision and saccades remain calibrated. The central nervous system network involved in these adaptive processes remains unclear because of difficulties in isolating the learning process from the correlated visual and motor processes. Here we imaged the human brain during a novel saccade adaptation paradigm that allowed us to isolate neural signals involved in learning independent of the changes in the amplitude of corrective saccades usually correlated with adap- tation. We show that the changes in activation in the ipsiversive cerebellar vermis that track adaptation are not driven by the changes in corrective saccades and thus provide critical supporting evidence for previous findings. Similarly, we find that activation in the dorso- medial wall of the contraversive precuneus mirrors the pattern found in the cerebellum. Finally, we identify dorsolateral and dorsomedial cortical areas in the frontal and parietal lobes that encode the retinal errors following inaccurate saccades used to drive recalibration. To- gether, these data identify a distributed network of cerebellar and cortical areas and their specific roles in oculomotor learning. |
M Guitart-Masip; G R Barnes; A Horner; Markus Bauer; Raymond J Dolan; E Duzel Synchronization of medial temporal lobe and prefrontal rhythms in human decision making Journal Article Journal of Neuroscience, 33 (2), pp. 442–451, 2013. @article{GuitartMasip2013, title = {Synchronization of medial temporal lobe and prefrontal rhythms in human decision making}, author = {M Guitart-Masip and G R Barnes and A Horner and Markus Bauer and Raymond J Dolan and E Duzel}, doi = {10.1523/JNEUROSCI.2573-12.2013}, year = {2013}, date = {2013-01-01}, journal = {Journal of Neuroscience}, volume = {33}, number = {2}, pages = {442--451}, abstract = {Optimal decision making requires that we integrate mnemonic information regarding previous decisions with value signals that entail likely rewards and punishments. The fact that memory and value signals appear to be coded by segregated brain regions, the hippocampus in the case of memory and sectors of prefrontal cortex in the case of value, raises the question as to how they are integrated during human decision making. Using magnetoencephalography to study healthy human participants, we show increased theta oscillations over frontal and temporal sensors during nonspatial decisions based on memories from previous trials. Using source reconstruction we found that the medial temporal lobe (MTL), in a location compatible with the anterior hippocampus, and the anterior cingulate cortex in the medial wall of the frontal lobe are the source of this increased theta power. Moreover, we observed a correlation between theta power in the MTL source and behavioral performance in decision making, supporting a role for MTL theta oscillations in decision-making performance. These MTL theta oscillations were synchronized with several prefrontal sources, including lateral superior frontal gyrus, dorsal anterior cingulate gyrus, and medial frontopolar cortex. There was no relationship between the strength of synchronization and the expected value of choices. Our results indicate a mnemonic guidance of human decision making, beyond anticipation of expected reward, is supported by hippocampal-prefrontal theta synchronization.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Optimal decision making requires that we integrate mnemonic information regarding previous decisions with value signals that entail likely rewards and punishments. The fact that memory and value signals appear to be coded by segregated brain regions, the hippocampus in the case of memory and sectors of prefrontal cortex in the case of value, raises the question as to how they are integrated during human decision making. Using magnetoencephalography to study healthy human participants, we show increased theta oscillations over frontal and temporal sensors during nonspatial decisions based on memories from previous trials. Using source reconstruction we found that the medial temporal lobe (MTL), in a location compatible with the anterior hippocampus, and the anterior cingulate cortex in the medial wall of the frontal lobe are the source of this increased theta power. Moreover, we observed a correlation between theta power in the MTL source and behavioral performance in decision making, supporting a role for MTL theta oscillations in decision-making performance. These MTL theta oscillations were synchronized with several prefrontal sources, including lateral superior frontal gyrus, dorsal anterior cingulate gyrus, and medial frontopolar cortex. There was no relationship between the strength of synchronization and the expected value of choices. Our results indicate a mnemonic guidance of human decision making, beyond anticipation of expected reward, is supported by hippocampal-prefrontal theta synchronization. |
Fei Guo; Tim J Preston; Koel Das; Barry Giesbrecht; Miguel P Eckstein Feature-independent neural coding of target detection during search of natural scenes Journal Article Journal of Neuroscience, 32 (28), pp. 9499–9510, 2012. @article{Guo2012, title = {Feature-independent neural coding of target detection during search of natural scenes}, author = {Fei Guo and Tim J Preston and Koel Das and Barry Giesbrecht and Miguel P Eckstein}, doi = {10.1523/JNEUROSCI.5876-11.2012}, year = {2012}, date = {2012-01-01}, journal = {Journal of Neuroscience}, volume = {32}, number = {28}, pages = {9499--9510}, abstract = {Visual search requires humans to detect a great variety of target objects in scenes cluttered by other objects or the natural environment. It is unknown whether there is a general purpose neural detection mechanism in the brain that codes the presence of a wide variety of categories of objects embedded in natural scenes. We provide evidence for a feature-independent coding mechanism for detecting behaviorally relevant targets in natural scenes in the dorsal frontoparietal network. Pattern classifiers using single-trial fMRI responses in the dorsal frontoparietal network reliably predicted the presence of 368 different target objects and also the observer's choices. Other vision-related areas such as the primary visual cortex, lateral occipital complex, the parahippocampal, and the fusiform gyri did not predict target presence, while high-level association areas related to general purpose decision making, including the dorsolateral prefrontal cortex and anterior cingulate, did. Activity in the intraparietal sulcus, a main area in the dorsal frontoparietal network, correlated with observers' decision confidence and with the task difficulty of individual images. These results cannot be explained by physical differences across images or eye movements. Thus, the dorsal frontoparietal network detects behaviorally relevant targets in natural scenes independent of their defining visual features and may be the human analog of the priority map in monkey lateral intraparietal cortex.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Visual search requires humans to detect a great variety of target objects in scenes cluttered by other objects or the natural environment. It is unknown whether there is a general purpose neural detection mechanism in the brain that codes the presence of a wide variety of categories of objects embedded in natural scenes. We provide evidence for a feature-independent coding mechanism for detecting behaviorally relevant targets in natural scenes in the dorsal frontoparietal network. Pattern classifiers using single-trial fMRI responses in the dorsal frontoparietal network reliably predicted the presence of 368 different target objects and also the observer's choices. Other vision-related areas such as the primary visual cortex, lateral occipital complex, the parahippocampal, and the fusiform gyri did not predict target presence, while high-level association areas related to general purpose decision making, including the dorsolateral prefrontal cortex and anterior cingulate, did. Activity in the intraparietal sulcus, a main area in the dorsal frontoparietal network, correlated with observers' decision confidence and with the task difficulty of individual images. These results cannot be explained by physical differences across images or eye movements. Thus, the dorsal frontoparietal network detects behaviorally relevant targets in natural scenes independent of their defining visual features and may be the human analog of the priority map in monkey lateral intraparietal cortex. |
Arvid Guterstam; Andrew I Wilterson; Davis Wachtell; Michael S A Graziano Other people's gaze encoded as implied motion in the human brain Journal Article Proceedings of the National Academy of Sciences, 117 (23), pp. 13162–13167, 2020. @article{Guterstam2020a, title = {Other people's gaze encoded as implied motion in the human brain}, author = {Arvid Guterstam and Andrew I Wilterson and Davis Wachtell and Michael S A Graziano}, doi = {10.1073/pnas.2003110117}, year = {2020}, date = {2020-01-01}, journal = {Proceedings of the National Academy of Sciences}, volume = {117}, number = {23}, pages = {13162--13167}, abstract = {Keeping track of other people's gaze is an essential task in social cognition and key for successfully reading other people's intentions and beliefs (theory of mind). Recent behavioral evidence suggests that we construct an implicit model of other people's gaze, which may incorporate physically incoherent attributes such as a construct of force-carrying beams that emanate from the eyes. Here, we used functional magnetic resonance imaging and multivoxel pattern analysis to test the prediction that the brain encodes gaze as implied motion streaming from an agent toward a gazed-upon object. We found that a classifier, trained to discriminate the direction of visual motion, significantly decoded the gaze direction in static images depicting a sighted face, but not a blindfolded one, from brain activity patterns in the human motion-sensitive middle temporal complex (MT+) and temporo-parietal junction (TPJ). Our results demonstrate a link between the visual motion system and social brain mechanisms, in which the TPJ, a key node in theory of mind, works in concert with MT+ to encode gaze as implied motion. This model may be a fundamental aspect of social cognition that allows us to efficiently connect agents with the objects of their attention. It is as if the brain draws a quick visual sketch with moving arrows to help keep track of who is attending to what. This implicit, fluid-flow model of other people's gaze may help explain culturally universal myths about the mind as an energy-like, flowing essence.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Keeping track of other people's gaze is an essential task in social cognition and key for successfully reading other people's intentions and beliefs (theory of mind). Recent behavioral evidence suggests that we construct an implicit model of other people's gaze, which may incorporate physically incoherent attributes such as a construct of force-carrying beams that emanate from the eyes. Here, we used functional magnetic resonance imaging and multivoxel pattern analysis to test the prediction that the brain encodes gaze as implied motion streaming from an agent toward a gazed-upon object. We found that a classifier, trained to discriminate the direction of visual motion, significantly decoded the gaze direction in static images depicting a sighted face, but not a blindfolded one, from brain activity patterns in the human motion-sensitive middle temporal complex (MT+) and temporo-parietal junction (TPJ). Our results demonstrate a link between the visual motion system and social brain mechanisms, in which the TPJ, a key node in theory of mind, works in concert with MT+ to encode gaze as implied motion. This model may be a fundamental aspect of social cognition that allows us to efficiently connect agents with the objects of their attention. It is as if the brain draws a quick visual sketch with moving arrows to help keep track of who is attending to what. This implicit, fluid-flow model of other people's gaze may help explain culturally universal myths about the mind as an energy-like, flowing essence. |
Michelle I C de Haan; Sonja van Wel; Renée M Visser; Steven H Scholte; Guido A van Wingen; Merel Kind The influence of acoustic startle probes on fear learning in humans Journal Article Scientific Reports, 8 , pp. 14552, 2018. @article{Haan2018, title = {The influence of acoustic startle probes on fear learning in humans}, author = {Michelle I C de Haan and Sonja van Wel and Renée M Visser and Steven H Scholte and Guido A van Wingen and Merel Kind}, doi = {10.1038/s41598-018-32646-1}, year = {2018}, date = {2018-01-01}, journal = {Scientific Reports}, volume = {8}, pages = {14552}, abstract = {Even though human fear-conditioning involves affective learning as well as expectancy learning, most studies assess only one of the two distinct processes. Commonly used read-outs of associative fear learning are the fear-potentiated startle reflex (FPS), pupil dilation and US-expectancy ratings. FPS is thought to reflect the affective aspect of fear learning, while pupil dilation reflects a general arousal response. However, in order to measure FPS, aversively loud acoustic probes are presented during conditioning, which might in itself exert an effect on fear learning. Here we tested the effect of startle probes on fear learning by comparing brain activation (fMRI), pupil dilation and US-expectancy ratings with and without acoustic startle probes within subjects. Regardless of startle probes, fear conditioning resulted in enhanced dACC, insula and ventral striatum activation. Interaction analyses showed that startle probes diminished differential pupil dilation between CS+ and CS− due to increased pupil responses to CS−. A trend significant interaction effect was observed for US-expectancy and amygdala activation. Startle probes affect differential fear learning by impeding safety learning, as measured with pupil dilation, a read-out of the cognitive component of fear learning. However, we observed no significant effect of acoustic startle probes on other measures of fear learning.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Even though human fear-conditioning involves affective learning as well as expectancy learning, most studies assess only one of the two distinct processes. Commonly used read-outs of associative fear learning are the fear-potentiated startle reflex (FPS), pupil dilation and US-expectancy ratings. FPS is thought to reflect the affective aspect of fear learning, while pupil dilation reflects a general arousal response. However, in order to measure FPS, aversively loud acoustic probes are presented during conditioning, which might in itself exert an effect on fear learning. Here we tested the effect of startle probes on fear learning by comparing brain activation (fMRI), pupil dilation and US-expectancy ratings with and without acoustic startle probes within subjects. Regardless of startle probes, fear conditioning resulted in enhanced dACC, insula and ventral striatum activation. Interaction analyses showed that startle probes diminished differential pupil dilation between CS+ and CS− due to increased pupil responses to CS−. A trend significant interaction effect was observed for US-expectancy and amygdala activation. Startle probes affect differential fear learning by impeding safety learning, as measured with pupil dilation, a read-out of the cognitive component of fear learning. However, we observed no significant effect of acoustic startle probes on other measures of fear learning. |
Michelle G Hall; Claire K Naughtin; Jason B Mattingley; Paul E Dux Distributed and opposing effects of incidental learning in the human brain Journal Article NeuroImage, 173 , pp. 351–360, 2018. @article{Hall2018b, title = {Distributed and opposing effects of incidental learning in the human brain}, author = {Michelle G Hall and Claire K Naughtin and Jason B Mattingley and Paul E Dux}, doi = {10.1016/j.neuroimage.2018.02.068}, year = {2018}, date = {2018-01-01}, journal = {NeuroImage}, volume = {173}, pages = {351--360}, publisher = {Elsevier Ltd}, abstract = {Incidental learning affords a behavioural advantage when sensory information matches regularities that have previously been encountered. Previous studies have taken a focused approach by probing the involvement of specific candidate brain regions underlying incidentally acquired memory representations, as well as expectation effects on early sensory representations. Here, we investigated the broader extent of the brain's sensitivity to violations and fulfilments of expectations, using an incidental learning paradigm in which the contingencies between target locations and target identities were manipulated without participants' overt knowledge. Multivariate analysis of functional magnetic resonance imaging data was applied to compare the consistency of neural activity for visual events that the contingency manipulation rendered likely versus unlikely. We observed widespread sensitivity to expectations across frontal, temporal, occipital, and sub-cortical areas. These activation clusters showed distinct response profiles, such that some regions displayed more reliable activation patterns under fulfilled expectations, whereas others showed more reliable patterns when expectations were violated. These findings reveal that expectations affect multiple stages of information processing during visual decision making, rather than early sensory processing stages alone.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Incidental learning affords a behavioural advantage when sensory information matches regularities that have previously been encountered. Previous studies have taken a focused approach by probing the involvement of specific candidate brain regions underlying incidentally acquired memory representations, as well as expectation effects on early sensory representations. Here, we investigated the broader extent of the brain's sensitivity to violations and fulfilments of expectations, using an incidental learning paradigm in which the contingencies between target locations and target identities were manipulated without participants' overt knowledge. Multivariate analysis of functional magnetic resonance imaging data was applied to compare the consistency of neural activity for visual events that the contingency manipulation rendered likely versus unlikely. We observed widespread sensitivity to expectations across frontal, temporal, occipital, and sub-cortical areas. These activation clusters showed distinct response profiles, such that some regions displayed more reliable activation patterns under fulfilled expectations, whereas others showed more reliable patterns when expectations were violated. These findings reveal that expectations affect multiple stages of information processing during visual decision making, rather than early sensory processing stages alone. |
Kristen R Hamilton; Jason F Smith; Stefanie F Gonçalves; Jazlyn A Nketia; Olivia N Tasheuras; Mark Yoon; Katya Rubia; Theresa J Chirles; Carl W Lejuez; Alexander J Shackman Striatal bases of temporal discounting in early adolescents Journal Article Neuropsychologia, 144 , pp. 1–11, 2020. @article{Hamilton2020, title = {Striatal bases of temporal discounting in early adolescents}, author = {Kristen R Hamilton and Jason F Smith and Stefanie F Gon{ç}alves and Jazlyn A Nketia and Olivia N Tasheuras and Mark Yoon and Katya Rubia and Theresa J Chirles and Carl W Lejuez and Alexander J Shackman}, doi = {10.1016/j.neuropsychologia.2020.107492}, year = {2020}, date = {2020-01-01}, journal = {Neuropsychologia}, volume = {144}, pages = {1--11}, abstract = {Steeper rates of temporal discounting—the degree to which smaller-sooner (SS) rewards are preferred over larger-later (LL) ones—have been associated with impulsive and ill-advised behaviors in adolescence. Yet, the underlying neural systems remain poorly understood. Here we used a well-established temporal discounting paradigm and functional MRI (fMRI) to examine engagement of the striatum—including the caudate, putamen, and ventral striatum (VS)—in early adolescence (13–15 years; N = 27). Analyses provided evidence of enhanced activity in the caudate and VS during impulsive choice. Exploratory analyses revealed that trait impulsivity was associated with heightened putamen activity during impulsive choices. A more nuanced pattern was evident in the cortex, with the dorsolateral prefrontal cortex mirroring the putamen and posterior parietal cortex showing the reverse association. Taken together, these observations provide an important first glimpse at the distributed neural systems underlying economic choice and trait-like individual differences in impulsivity in the early years of adolescence, setting the stage for prospective-longitudinal and intervention research.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Steeper rates of temporal discounting—the degree to which smaller-sooner (SS) rewards are preferred over larger-later (LL) ones—have been associated with impulsive and ill-advised behaviors in adolescence. Yet, the underlying neural systems remain poorly understood. Here we used a well-established temporal discounting paradigm and functional MRI (fMRI) to examine engagement of the striatum—including the caudate, putamen, and ventral striatum (VS)—in early adolescence (13–15 years; N = 27). Analyses provided evidence of enhanced activity in the caudate and VS during impulsive choice. Exploratory analyses revealed that trait impulsivity was associated with heightened putamen activity during impulsive choices. A more nuanced pattern was evident in the cortex, with the dorsolateral prefrontal cortex mirroring the putamen and posterior parietal cortex showing the reverse association. Taken together, these observations provide an important first glimpse at the distributed neural systems underlying economic choice and trait-like individual differences in impulsivity in the early years of adolescence, setting the stage for prospective-longitudinal and intervention research. |
Michael Hanke; Nico Adelhöfer; Daniel Kottke; Vittorio Iacovella; Ayan Sengupta; Falko R Kaule; Roland Nigbur; Alexander Q Waite; Florian Baumgartner; Jörg Stadler A studyforrest extension, simultaneous fMRI and eye gaze recordings during prolonged natural stimulation Journal Article Scientific Data, 3 , pp. 1–15, 2016. @article{Hanke2016, title = {A studyforrest extension, simultaneous fMRI and eye gaze recordings during prolonged natural stimulation}, author = {Michael Hanke and Nico Adelhöfer and Daniel Kottke and Vittorio Iacovella and Ayan Sengupta and Falko R Kaule and Roland Nigbur and Alexander Q Waite and Florian Baumgartner and Jörg Stadler}, doi = {10.1038/sdata.2016.92}, year = {2016}, date = {2016-01-01}, journal = {Scientific Data}, volume = {3}, pages = {1--15}, abstract = {Here we present an update of the studyforrest (http://studyforrest.org) dataset that complements the previously released functional magnetic resonance imaging (fMRI) data for natural language processing with a new two-hour 3 Tesla fMRI acquisition while 15 of the original participants were shown an audio-visual version of the stimulus motion picture. We demonstrate with two validation analyses that these new data support modeling specific properties of the complex natural stimulus, as well as a substantial within-subject BOLD response congruency in brain areas related to the processing of auditory inputs, speech, and narrative when compared to the existing fMRI data for audio-only stimulation. In addition, we provide participants' eye gaze location as recorded simultaneously with fMRI, and an additional sample of 15 control participants whose eye gaze trajectories for the entire movie were recorded in a lab setting-to enable studies on attentional processes and comparative investigations on the potential impact of the stimulation setting on these processes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Here we present an update of the studyforrest (http://studyforrest.org) dataset that complements the previously released functional magnetic resonance imaging (fMRI) data for natural language processing with a new two-hour 3 Tesla fMRI acquisition while 15 of the original participants were shown an audio-visual version of the stimulus motion picture. We demonstrate with two validation analyses that these new data support modeling specific properties of the complex natural stimulus, as well as a substantial within-subject BOLD response congruency in brain areas related to the processing of auditory inputs, speech, and narrative when compared to the existing fMRI data for audio-only stimulation. In addition, we provide participants' eye gaze location as recorded simultaneously with fMRI, and an additional sample of 15 control participants whose eye gaze trajectories for the entire movie were recorded in a lab setting-to enable studies on attentional processes and comparative investigations on the potential impact of the stimulation setting on these processes. |
Michael P Harms; Leah H Somerville; Beau M Ances; Jesper Andersson; Deanna M Barch; Matteo Bastiani; Susan Y Bookheimer; Timothy B Brown; Randy L Buckner; Gregory C Burgess; Timothy S Coalson; Michael A Chappell; Mirella Dapretto; Gwenaëlle Douaud; Bruce Fischl; Matthew F Glasser; Douglas N Greve; Cynthia Hodge; Keith W Jamison; Saad Jbabdi; Sridhar Kandala; Xiufeng Li; Ross W Mair; Silvia Mangia; Daniel Marcus; Daniele Mascali; Steen Moeller; Thomas E Nichols; Emma C Robinson; David H Salat; Stephen M Smith; Stamatios N Sotiropoulos; Melissa Terpstra; Kathleen M Thomas; Dylan M Tisdall; Kamil Ugurbil; Andre van der Kouwe; Roger P Woods; Lilla Zöllei; David C Van Essen; Essa Yacoub Extending the Human Connectome Project across ages: Imaging protocols for the Lifespan Development and Aging projects Journal Article NeuroImage, 183 , pp. 972–984, 2018. @article{Harms2018, title = {Extending the Human Connectome Project across ages: Imaging protocols for the Lifespan Development and Aging projects}, author = {Michael P Harms and Leah H Somerville and Beau M Ances and Jesper Andersson and Deanna M Barch and Matteo Bastiani and Susan Y Bookheimer and Timothy B Brown and Randy L Buckner and Gregory C Burgess and Timothy S Coalson and Michael A Chappell and Mirella Dapretto and Gwena{ë}lle Douaud and Bruce Fischl and Matthew F Glasser and Douglas N Greve and Cynthia Hodge and Keith W Jamison and Saad Jbabdi and Sridhar Kandala and Xiufeng Li and Ross W Mair and Silvia Mangia and Daniel Marcus and Daniele Mascali and Steen Moeller and Thomas E Nichols and Emma C Robinson and David H Salat and Stephen M Smith and Stamatios N Sotiropoulos and Melissa Terpstra and Kathleen M Thomas and Dylan M Tisdall and Kamil Ugurbil and Andre van der Kouwe and Roger P Woods and Lilla Zöllei and David C {Van Essen} and Essa Yacoub}, doi = {10.1016/j.neuroimage.2018.09.060}, year = {2018}, date = {2018-01-01}, journal = {NeuroImage}, volume = {183}, pages = {972--984}, abstract = {The Human Connectome Projects in Development (HCP-D) and Aging (HCP-A) are two large-scale brain imaging studies that will extend the recently completed HCP Young-Adult (HCP-YA) project to nearly the full lifespan, collecting structural, resting-state fMRI, task-fMRI, diffusion, and perfusion MRI in participants from 5 to 100+ years of age. HCP-D is enrolling 1300+ healthy children, adolescents, and young adults (ages 5–21), and HCP-A is enrolling 1200+ healthy adults (ages 36–100+), with each study collecting longitudinal data in a subset of individuals at particular age ranges. The imaging protocols of the HCP-D and HCP-A studies are very similar, differing primarily in the selection of different task-fMRI paradigms. We strove to harmonize the imaging protocol to the greatest extent feasible with the completed HCP-YA (1200+ participants, aged 22–35), but some imaging-related changes were motivated or necessitated by hardware changes, the need to reduce the total amount of scanning per participant, and/or the additional challenges of working with young and elderly populations. Here, we provide an overview of the common HCP-D/A imaging protocol including data and rationales for protocol decisions and changes relative to HCP-YA. The result will be a large, rich, multi-modal, and freely available set of consistently acquired data for use by the scientific community to investigate and define normative developmental and aging related changes in the healthy human brain.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The Human Connectome Projects in Development (HCP-D) and Aging (HCP-A) are two large-scale brain imaging studies that will extend the recently completed HCP Young-Adult (HCP-YA) project to nearly the full lifespan, collecting structural, resting-state fMRI, task-fMRI, diffusion, and perfusion MRI in participants from 5 to 100+ years of age. HCP-D is enrolling 1300+ healthy children, adolescents, and young adults (ages 5–21), and HCP-A is enrolling 1200+ healthy adults (ages 36–100+), with each study collecting longitudinal data in a subset of individuals at particular age ranges. The imaging protocols of the HCP-D and HCP-A studies are very similar, differing primarily in the selection of different task-fMRI paradigms. We strove to harmonize the imaging protocol to the greatest extent feasible with the completed HCP-YA (1200+ participants, aged 22–35), but some imaging-related changes were motivated or necessitated by hardware changes, the need to reduce the total amount of scanning per participant, and/or the additional challenges of working with young and elderly populations. Here, we provide an overview of the common HCP-D/A imaging protocol including data and rationales for protocol decisions and changes relative to HCP-YA. The result will be a large, rich, multi-modal, and freely available set of consistently acquired data for use by the scientific community to investigate and define normative developmental and aging related changes in the healthy human brain. |
Wei He; Jon Brock; Blake W Johnson Face-sensitive brain responses measured from a four-year-old child with a custom-sized child MEG system Journal Article Journal of Neuroscience Methods, 222 , pp. 213–217, 2014. @article{He2014c, title = {Face-sensitive brain responses measured from a four-year-old child with a custom-sized child MEG system}, author = {Wei He and Jon Brock and Blake W Johnson}, doi = {10.1016/j.jneumeth.2013.11.020}, year = {2014}, date = {2014-01-01}, journal = {Journal of Neuroscience Methods}, volume = {222}, pages = {213--217}, publisher = {222}, abstract = {Background: Previous magnetoencephalography (MEG) studies have failed to find a facesensitive, brain response-M170 in children. If this is the case, this suggests that the developmental trajectory of the M170 is different from that of its electrical equivalent, the N170. We investigated the alternative possibility that the child M170 may not be detectable in conventional adult-sized MEG systems. New method: Brain responses to pictures of faces and well controlled stimuli were measured from the same four-year-old child with a custom child MEG system and an adult-sized MEG system. Results: The goodness of fit of the child's head was about the same over the occipital head surface in both systems, but was much worse over all other parts of the head surface in the adult MEG system compared to the child MEG system. The face-sensitive M170 was measured from the child in both MEG systems, but was larger in amplitude, clearer in morphology, and had a more accurate source localization when measured in the child MEG system. Comparison with existing method: The custom-sized child MEG system is superior for measuring the face-sensitive M170 brain response in children than the conventional adult MEG system. Conclusions: The present results show that the face-sensitive M170 brain response can be elicited in a four-year-old child. This provides new evidence for early maturation of face processing brain mechanisms in humans, and offers new opportunities for the study of neurodevelopmental disorders that show atypical face processing capabilities, such as autism spectrum disorder.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: Previous magnetoencephalography (MEG) studies have failed to find a facesensitive, brain response-M170 in children. If this is the case, this suggests that the developmental trajectory of the M170 is different from that of its electrical equivalent, the N170. We investigated the alternative possibility that the child M170 may not be detectable in conventional adult-sized MEG systems. New method: Brain responses to pictures of faces and well controlled stimuli were measured from the same four-year-old child with a custom child MEG system and an adult-sized MEG system. Results: The goodness of fit of the child's head was about the same over the occipital head surface in both systems, but was much worse over all other parts of the head surface in the adult MEG system compared to the child MEG system. The face-sensitive M170 was measured from the child in both MEG systems, but was larger in amplitude, clearer in morphology, and had a more accurate source localization when measured in the child MEG system. Comparison with existing method: The custom-sized child MEG system is superior for measuring the face-sensitive M170 brain response in children than the conventional adult MEG system. Conclusions: The present results show that the face-sensitive M170 brain response can be elicited in a four-year-old child. This provides new evidence for early maturation of face processing brain mechanisms in humans, and offers new opportunities for the study of neurodevelopmental disorders that show atypical face processing capabilities, such as autism spectrum disorder. |
Wei He; Jon Brock; Blake W Johnson Face processing in the brains of pre-school aged children measured with MEG Journal Article NeuroImage, 106 , pp. 317–327, 2015. @article{He2015a, title = {Face processing in the brains of pre-school aged children measured with MEG}, author = {Wei He and Jon Brock and Blake W Johnson}, doi = {10.1016/j.neuroimage.2014.11.029}, year = {2015}, date = {2015-01-01}, journal = {NeuroImage}, volume = {106}, pages = {317--327}, publisher = {Elsevier Inc.}, abstract = {There are two competing theories concerning the development of face perception: a late maturation account and an early maturation account. Magnetoencephalography (MEG) neuroimaging holds promise for adjudicating between the two opposing accounts by providing objective neurophysiological measures of face processing, with sufficient temporal resolution to isolate face-specific brain responses from those associated with other sensory, cognitive and motor processes. The current study used a customized child MEG system to measure M100 and M170 brain responses in 15 children aged three to six years while they viewed faces, cars and their phase-scrambled counterparts. Compared to adults tested using the same stimuli in a conventional MEG system, children showed significantly larger and later M100 responses. Children's M170 responses, derived by subtracting the responses to phase-scrambled images from the corresponding images (faces or cars) were delayed in latency but otherwise resembled the adult M170. This component has not been obtained in previous studies of young children tested using conventional adult MEG systems. However children did show a markedly reduced M170 response to cars in comparison to adults. This may reflect children's lack of expertise with cars relative to faces. Taken together, these data are in accord with recent behavioural and neuroimaging data that support early maturation of the basic face processing functions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } There are two competing theories concerning the development of face perception: a late maturation account and an early maturation account. Magnetoencephalography (MEG) neuroimaging holds promise for adjudicating between the two opposing accounts by providing objective neurophysiological measures of face processing, with sufficient temporal resolution to isolate face-specific brain responses from those associated with other sensory, cognitive and motor processes. The current study used a customized child MEG system to measure M100 and M170 brain responses in 15 children aged three to six years while they viewed faces, cars and their phase-scrambled counterparts. Compared to adults tested using the same stimuli in a conventional MEG system, children showed significantly larger and later M100 responses. Children's M170 responses, derived by subtracting the responses to phase-scrambled images from the corresponding images (faces or cars) were delayed in latency but otherwise resembled the adult M170. This component has not been obtained in previous studies of young children tested using conventional adult MEG systems. However children did show a markedly reduced M170 response to cars in comparison to adults. This may reflect children's lack of expertise with cars relative to faces. Taken together, these data are in accord with recent behavioural and neuroimaging data that support early maturation of the basic face processing functions. |
Wei He; Marta I Garrido; Paul F Sowman; Jon Brock; Blake W Johnson Development of effective connectivity in the core network for face perception Journal Article Human Brain Mapping, 36 (6), pp. 2161–2173, 2015. @article{He2015b, title = {Development of effective connectivity in the core network for face perception}, author = {Wei He and Marta I Garrido and Paul F Sowman and Jon Brock and Blake W Johnson}, doi = {10.1002/hbm.22762}, year = {2015}, date = {2015-01-01}, journal = {Human Brain Mapping}, volume = {36}, number = {6}, pages = {2161--2173}, abstract = {This study measured effective connectivity within the core face network in young children using a paediatric magnetoencephalograph (MEG). Dynamic casual modeling (DCM) of brain responses was performed in a group of adults (N = 14) and a group of young children aged from 3 to 6 years (N = 15). Three candidate DCM models were tested, and the fits of the MEG data to the three models were compared at both individual and group levels. The results show that the connectivity structure of the core face network differs significantly between adults and children. Further, the relative strengths of face network connections were differentially modulated by experimental conditions in the two groups. These results support the interpretation that the core face network undergoes significant structural configuration and functional specialization between four years of age and adulthood.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This study measured effective connectivity within the core face network in young children using a paediatric magnetoencephalograph (MEG). Dynamic casual modeling (DCM) of brain responses was performed in a group of adults (N = 14) and a group of young children aged from 3 to 6 years (N = 15). Three candidate DCM models were tested, and the fits of the MEG data to the three models were compared at both individual and group levels. The results show that the connectivity structure of the core face network differs significantly between adults and children. Further, the relative strengths of face network connections were differentially modulated by experimental conditions in the two groups. These results support the interpretation that the core face network undergoes significant structural configuration and functional specialization between four years of age and adulthood. |
Wei He; Blake W Johnson Development of face recognition: Dynamic causal modelling of MEG data Journal Article Developmental Cognitive Neuroscience, 30 , pp. 13–22, 2018. @article{He2018f, title = {Development of face recognition: Dynamic causal modelling of MEG data}, author = {Wei He and Blake W Johnson}, doi = {10.1016/j.dcn.2017.11.010}, year = {2018}, date = {2018-01-01}, journal = {Developmental Cognitive Neuroscience}, volume = {30}, pages = {13--22}, publisher = {Elsevier}, abstract = {Electrophysiological studies of adults indicate that brain activity is enhanced during viewing of repeated faces, at a latency of about 250 ms after the onset of the face (M250/N250). The present study aimed to determine if this effect was also present in preschool-aged children, whose brain activity was measured in a custom-sized pediatric MEG system. The results showed that, unlike adults, face repetition did not show any significant modulation of M250 amplitude in children; however children's M250 latencies were significantly faster for repeated than non-repeated faces. Dynamic causal modelling (DCM) of the M250 in both age groups tested the effects of face repetition within the core face network including the occipital face area (OFA), the fusiform face area (FFA), and the superior temporal sulcus (STS). DCM revealed that repetition of identical faces altered both forward and backward connections in children and adults; however the modulations involved inputs to both FFA and OFA in adults but only to OFA in children. These findings suggest that the amplitude-insensitivity of the immature M250 may be due to a weaker connection between the FFA and lower visual areas.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Electrophysiological studies of adults indicate that brain activity is enhanced during viewing of repeated faces, at a latency of about 250 ms after the onset of the face (M250/N250). The present study aimed to determine if this effect was also present in preschool-aged children, whose brain activity was measured in a custom-sized pediatric MEG system. The results showed that, unlike adults, face repetition did not show any significant modulation of M250 amplitude in children; however children's M250 latencies were significantly faster for repeated than non-repeated faces. Dynamic causal modelling (DCM) of the M250 in both age groups tested the effects of face repetition within the core face network including the occipital face area (OFA), the fusiform face area (FFA), and the superior temporal sulcus (STS). DCM revealed that repetition of identical faces altered both forward and backward connections in children and adults; however the modulations involved inputs to both FFA and OFA in adults but only to OFA in children. These findings suggest that the amplitude-insensitivity of the immature M250 may be due to a weaker connection between the FFA and lower visual areas. |
Simone G Heideman; Gustavo Rohenkohl; Joshua J Chauvin; Clare E Palmer; Freek van Ede; Anna C Nobre Anticipatory neural dynamics of spatial-temporal orienting of attention in younger and older adults Journal Article NeuroImage, 178 , pp. 46–56, 2018. @article{Heideman2018a, title = {Anticipatory neural dynamics of spatial-temporal orienting of attention in younger and older adults}, author = {Simone G Heideman and Gustavo Rohenkohl and Joshua J Chauvin and Clare E Palmer and Freek van Ede and Anna C Nobre}, doi = {10.1016/j.neuroimage.2018.05.002}, year = {2018}, date = {2018-01-01}, journal = {NeuroImage}, volume = {178}, pages = {46--56}, publisher = {Elsevier Ltd}, abstract = {Spatial and temporal expectations act synergistically to facilitate visual perception. In the current study, we sought to investigate the anticipatory oscillatory markers of combined spatial-temporal orienting and to test whether these decline with ageing. We examined anticipatory neural dynamics associated with joint spatial-temporal orienting of attention using magnetoencephalography (MEG) in both younger and older adults. Participants performed a cued covert spatial-temporal orienting task requiring the discrimination of a visual target. Cues indicated both where and when targets would appear. In both age groups, valid spatial-temporal cues significantly enhanced perceptual sensitivity and reduced reaction times. In the MEG data, the main effect of spatial orienting was the lateralised anticipatory modulation of posterior alpha and beta oscillations. In contrast to previous reports, this modulation was not attenuated in older adults; instead it was even more pronounced. The main effect of temporal orienting was a bilateral suppression of posterior alpha and beta oscillations. This effect was restricted to younger adults. Our results also revealed a striking interaction between anticipatory spatial and temporal orienting in the gamma-band (60–75 Hz). When considering both age groups separately, this effect was only clearly evident and only survived statistical evaluation in the older adults. Together, these observations provide several new insights into the neural dynamics supporting separate as well as combined effects of spatial and temporal orienting of attention, and suggest that different neural dynamics associated with attentional orienting appear differentially sensitive to ageing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Spatial and temporal expectations act synergistically to facilitate visual perception. In the current study, we sought to investigate the anticipatory oscillatory markers of combined spatial-temporal orienting and to test whether these decline with ageing. We examined anticipatory neural dynamics associated with joint spatial-temporal orienting of attention using magnetoencephalography (MEG) in both younger and older adults. Participants performed a cued covert spatial-temporal orienting task requiring the discrimination of a visual target. Cues indicated both where and when targets would appear. In both age groups, valid spatial-temporal cues significantly enhanced perceptual sensitivity and reduced reaction times. In the MEG data, the main effect of spatial orienting was the lateralised anticipatory modulation of posterior alpha and beta oscillations. In contrast to previous reports, this modulation was not attenuated in older adults; instead it was even more pronounced. The main effect of temporal orienting was a bilateral suppression of posterior alpha and beta oscillations. This effect was restricted to younger adults. Our results also revealed a striking interaction between anticipatory spatial and temporal orienting in the gamma-band (60–75 Hz). When considering both age groups separately, this effect was only clearly evident and only survived statistical evaluation in the older adults. Together, these observations provide several new insights into the neural dynamics supporting separate as well as combined effects of spatial and temporal orienting of attention, and suggest that different neural dynamics associated with attentional orienting appear differentially sensitive to ageing. |
Simone G Heideman; Freek van Ede; Anna C Nobre Temporal alignment of anticipatory motor cortical beta lateralisation in hidden visual-motor sequences Journal Article European Journal of Neuroscience, 48 (8), pp. 2684–2695, 2018. @article{Heideman2018b, title = {Temporal alignment of anticipatory motor cortical beta lateralisation in hidden visual-motor sequences}, author = {Simone G Heideman and Freek van Ede and Anna C Nobre}, doi = {10.1111/ejn.13700}, year = {2018}, date = {2018-01-01}, journal = {European Journal of Neuroscience}, volume = {48}, number = {8}, pages = {2684--2695}, abstract = {Performance improves when participants respond to events that are structured in repeating sequences, suggesting that learning can lead to proactive anticipatory preparation. Whereas most sequence-learning studies have emphasised spatial structure, most sequences also contain a prominent temporal structure. We used MEG to investigate spatial and temporal anticipatory neural dynamics in a modified serial reaction time (SRT) task. Performance and brain activity were compared between blocks with learned spatial-temporal sequences and blocks with new sequences. After confirming a strong behavioural benefit of spatial-temporal predictability, we show lateralisation of beta oscillations in anticipation of the response associated with the upcoming target location and show that this also aligns to the expected timing of these forthcoming events. This effect was found both when comparing between repeated (learned) and new (unlearned) sequences, as well as when comparing targets that were expected after short vs. long intervals within the repeated (learned) sequence. Our findings suggest that learning of spatial-temporal structure leads to proactive and dynamic modulation of motor cortical excitability in anticipation of both the location and timing of events that are relevant to guide action.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Performance improves when participants respond to events that are structured in repeating sequences, suggesting that learning can lead to proactive anticipatory preparation. Whereas most sequence-learning studies have emphasised spatial structure, most sequences also contain a prominent temporal structure. We used MEG to investigate spatial and temporal anticipatory neural dynamics in a modified serial reaction time (SRT) task. Performance and brain activity were compared between blocks with learned spatial-temporal sequences and blocks with new sequences. After confirming a strong behavioural benefit of spatial-temporal predictability, we show lateralisation of beta oscillations in anticipation of the response associated with the upcoming target location and show that this also aligns to the expected timing of these forthcoming events. This effect was found both when comparing between repeated (learned) and new (unlearned) sequences, as well as when comparing targets that were expected after short vs. long intervals within the repeated (learned) sequence. Our findings suggest that learning of spatial-temporal structure leads to proactive and dynamic modulation of motor cortical excitability in anticipation of both the location and timing of events that are relevant to guide action. |
Hanna Heikkinen; Fariba Sharifian; Ricardo Vigario; Simo Vanni Feedback to distal dendrites links fMRI signals to neural receptive fields in a spiking network model of the visual cortex Journal Article Journal of Neurophysiology, 114 (1), pp. 57–69, 2015. @article{Heikkinen2015, title = {Feedback to distal dendrites links fMRI signals to neural receptive fields in a spiking network model of the visual cortex}, author = {Hanna Heikkinen and Fariba Sharifian and Ricardo Vigario and Simo Vanni}, doi = {10.1152/jn.00169.2015}, year = {2015}, date = {2015-01-01}, journal = {Journal of Neurophysiology}, volume = {114}, number = {1}, pages = {57--69}, abstract = {The blood oxygenation level-dependent (BOLD) response has been strongly associated with neuronal activity in the brain. However, some neuronal tuning properties are consistently different from the BOLD response. We studied the spatial extent of neural and hemodynamic responses in the primary visual cortex, where the BOLD responses spread and interact over much longer distances than the small receptive fields of individual neurons would predict. Our model shows that a feedforward-feedback loop between V1 and a higher visual area can account for the observed spread of the BOLD response. In particular, anisotropic landing of inputs to compartmental neurons were necessary to account for the BOLD signal spread, while retaining realistic spiking responses. Our work shows that simple dendrites can separate tuning at the synapses and at the action potential output, thus bridging the BOLD signal to the neural receptive fields with high fidelity.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The blood oxygenation level-dependent (BOLD) response has been strongly associated with neuronal activity in the brain. However, some neuronal tuning properties are consistently different from the BOLD response. We studied the spatial extent of neural and hemodynamic responses in the primary visual cortex, where the BOLD responses spread and interact over much longer distances than the small receptive fields of individual neurons would predict. Our model shows that a feedforward-feedback loop between V1 and a higher visual area can account for the observed spread of the BOLD response. In particular, anisotropic landing of inputs to compartmental neurons were necessary to account for the BOLD signal spread, while retaining realistic spiking responses. Our work shows that simple dendrites can separate tuning at the synapses and at the action potential output, thus bridging the BOLD signal to the neural receptive fields with high fidelity. |
Christoph Helmchen; Matthias Rother; Andreas Sprenger Increased brain responsivity to galvanic vestibular stimulation in bilateral vestibular failure Journal Article NeuroImage: Clinical, 24 , pp. 1–12, 2019. @article{Helmchen2019, title = {Increased brain responsivity to galvanic vestibular stimulation in bilateral vestibular failure}, author = {Christoph Helmchen and Matthias Rother and Andreas Sprenger}, doi = {10.1016/j.nicl.2019.101942}, year = {2019}, date = {2019-01-01}, journal = {NeuroImage: Clinical}, volume = {24}, pages = {1--12}, abstract = {In this event-related functional magnetic resonance imaging (fMRI) study we investigated how the brain of patients with bilateral vestibular failure (BVF) responds to vestibular stimuli. We used imperceptible noisy galvanic vestibular stimulation (GVS) and perceptible bi-mastoidal GVS intensities and related the corresponding brain activity to the evoked motion perception. In contrast to caloric irrigation, GVS stimulates the vestibular organ at its potentially intact afferent nerve site. Motion perception thresholds and cortical responses were compared between 26 BVF patients to 27 age-matched healthy control participants. To identify the specificity of vestibular cortical responses we used a parametric design with different stimulus intensities (noisy imperceptible, low perceptible, high perceptible) allowing region-specific stimulus response functions. In a 2 × 3 flexible factorial design all GVS-related brain activities were contrasted with a sham condition that did not evoke perceived motion. Patients had a higher motion perception threshold and rated the vestibular stimuli higher than the healthy participants. There was a stimulus intensity related and region-specific increase of activity with steep stimulus response functions in parietal operculum (e.g. OP2), insula, superior temporal gyrus, early visual cortices (V3) and cerebellum while activity in the hippocampus and intraparietal sulcus did not correlate with vestibular stimulus intensity. Using whole brain analysis, group comparisons revealed increased brain activity in early visual cortices (V3) and superior temporal gyrus of patients but there was no significant interaction, i.e. stimulus response function in these regions were still similar in both groups. Brain activity in these regions during (high)GVS increased with higher dizziness-related handicap scores but was not related to the degree of vestibular impairment or disease duration. nGVS did not evoke cortical responses in any group. Our data indicate that perceptible GVS-related cortical responsivity is not diminished but increased in mul-tisensory (visual-vestibular) cortical regions despite bilateral failure of the peripheral vestibular organ. The increased activity in early visual cortices (V3) and superior temporal gyrus of BVF patients has several potential implications: (i) their cortical reciprocal inhibitory visuo-vestibular interaction is dysfunctional, (ii) it may contribute to the visual dependency of BVF patients, and (iii) it needs to be considered when BVF patients receive peripheral vestibular stimulation devices, e.g. vestibular implants or portable GVS devices. Imperceptible nGVS did not elicit cortical brain responses making it unlikely that the reported balance improvement of BVF by nGVS is mediated by cortical mechanisms.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this event-related functional magnetic resonance imaging (fMRI) study we investigated how the brain of patients with bilateral vestibular failure (BVF) responds to vestibular stimuli. We used imperceptible noisy galvanic vestibular stimulation (GVS) and perceptible bi-mastoidal GVS intensities and related the corresponding brain activity to the evoked motion perception. In contrast to caloric irrigation, GVS stimulates the vestibular organ at its potentially intact afferent nerve site. Motion perception thresholds and cortical responses were compared between 26 BVF patients to 27 age-matched healthy control participants. To identify the specificity of vestibular cortical responses we used a parametric design with different stimulus intensities (noisy imperceptible, low perceptible, high perceptible) allowing region-specific stimulus response functions. In a 2 × 3 flexible factorial design all GVS-related brain activities were contrasted with a sham condition that did not evoke perceived motion. Patients had a higher motion perception threshold and rated the vestibular stimuli higher than the healthy participants. There was a stimulus intensity related and region-specific increase of activity with steep stimulus response functions in parietal operculum (e.g. OP2), insula, superior temporal gyrus, early visual cortices (V3) and cerebellum while activity in the hippocampus and intraparietal sulcus did not correlate with vestibular stimulus intensity. Using whole brain analysis, group comparisons revealed increased brain activity in early visual cortices (V3) and superior temporal gyrus of patients but there was no significant interaction, i.e. stimulus response function in these regions were still similar in both groups. Brain activity in these regions during (high)GVS increased with higher dizziness-related handicap scores but was not related to the degree of vestibular impairment or disease duration. nGVS did not evoke cortical responses in any group. Our data indicate that perceptible GVS-related cortical responsivity is not diminished but increased in mul-tisensory (visual-vestibular) cortical regions despite bilateral failure of the peripheral vestibular organ. The increased activity in early visual cortices (V3) and superior temporal gyrus of BVF patients has several potential implications: (i) their cortical reciprocal inhibitory visuo-vestibular interaction is dysfunctional, (ii) it may contribute to the visual dependency of BVF patients, and (iii) it needs to be considered when BVF patients receive peripheral vestibular stimulation devices, e.g. vestibular implants or portable GVS devices. Imperceptible nGVS did not elicit cortical brain responses making it unlikely that the reported balance improvement of BVF by nGVS is mediated by cortical mechanisms. |
Christoph Helmchen; Björn Machner; Matthias Rother; Peer Spliethoff; Martin Göttlich; Andreas Sprenger Effects of galvanic vestibular stimulation on resting state brain activity in patients with bilateral vestibulopathy Journal Article Human Brain Mapping, 41 (9), pp. 2527–2547, 2020. @article{Helmchen2020, title = {Effects of galvanic vestibular stimulation on resting state brain activity in patients with bilateral vestibulopathy}, author = {Christoph Helmchen and Björn Machner and Matthias Rother and Peer Spliethoff and Martin Göttlich and Andreas Sprenger}, doi = {10.1002/hbm.24963}, year = {2020}, date = {2020-01-01}, journal = {Human Brain Mapping}, volume = {41}, number = {9}, pages = {2527--2547}, abstract = {We examined the effect of galvanic vestibular stimulation (GVS) on resting state brain activity using fMRI (rs-fMRI) in patients with bilateral vestibulopathy. Based on our previous findings, we hypothesized that GVS, which excites the vestibular nerve fibers, (a) increases functional connectivity in temporoparietal regions processing vestibular signals, and (b) alleviates abnormal visual–vestibular interaction. Rs-fMRI of 26 patients and 26 age-matched healthy control subjects was compared before and after GVS. The stimulation elicited a motion percept in all participants. Using different analyses (degree centrality, DC; fractional amplitude of low frequency fluctuations [fALFF] and seed-based functional connectivity, FC), group comparisons revealed smaller rs-fMRI in the right Rolandic operculum of patients. After GVS, rs-fMRI increased in the right Rolandic operculum in both groups and in the patients' cerebellar Crus 1 which was related to vestibular hypofunction. GVS elicited a fALFF increase in the visual cortex of patients that was inversely correlated with the patients' rating of perceived dizziness. After GVS, FC between parietoinsular cortex and higher visual areas increased in healthy controls but not in patients. In conclusion, short-term GVS is able to modulate rs-fMRI in healthy controls and BV patients. GVS elicits an increase of the reduced rs-fMRI in the patients' right Rolandic operculum, which may be an important contribution to restore the disturbed visual–vestibular interaction. The GVS-induced changes in the cerebellum and the visual cortex were associated with lower dizziness-related handicaps in patients, possibly reflecting beneficial neural plasticity that might subserve visual–vestibular compensation of deficient self-motion perception.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We examined the effect of galvanic vestibular stimulation (GVS) on resting state brain activity using fMRI (rs-fMRI) in patients with bilateral vestibulopathy. Based on our previous findings, we hypothesized that GVS, which excites the vestibular nerve fibers, (a) increases functional connectivity in temporoparietal regions processing vestibular signals, and (b) alleviates abnormal visual–vestibular interaction. Rs-fMRI of 26 patients and 26 age-matched healthy control subjects was compared before and after GVS. The stimulation elicited a motion percept in all participants. Using different analyses (degree centrality, DC; fractional amplitude of low frequency fluctuations [fALFF] and seed-based functional connectivity, FC), group comparisons revealed smaller rs-fMRI in the right Rolandic operculum of patients. After GVS, rs-fMRI increased in the right Rolandic operculum in both groups and in the patients' cerebellar Crus 1 which was related to vestibular hypofunction. GVS elicited a fALFF increase in the visual cortex of patients that was inversely correlated with the patients' rating of perceived dizziness. After GVS, FC between parietoinsular cortex and higher visual areas increased in healthy controls but not in patients. In conclusion, short-term GVS is able to modulate rs-fMRI in healthy controls and BV patients. GVS elicits an increase of the reduced rs-fMRI in the patients' right Rolandic operculum, which may be an important contribution to restore the disturbed visual–vestibular interaction. The GVS-induced changes in the cerebellum and the visual cortex were associated with lower dizziness-related handicaps in patients, possibly reflecting beneficial neural plasticity that might subserve visual–vestibular compensation of deficient self-motion perception. |
Lara Henco; Marie Luise Brandi; Juha M Lahnakoski; Andreea O Diaconescu; Christoph Mathys; Leonhard Schilbach Bayesian modelling captures inter-individual differences in social belief computations in the putamen and insula Journal Article Cortex, 131 , pp. 221–236, 2020. @article{Henco2020, title = {Bayesian modelling captures inter-individual differences in social belief computations in the putamen and insula}, author = {Lara Henco and Marie Luise Brandi and Juha M Lahnakoski and Andreea O Diaconescu and Christoph Mathys and Leonhard Schilbach}, doi = {10.1016/j.cortex.2020.02.024}, year = {2020}, date = {2020-01-01}, journal = {Cortex}, volume = {131}, pages = {221--236}, publisher = {Elsevier Ltd}, abstract = {Computational models of social learning and decision-making provide mechanistic tools to investigate the neural mechanisms that are involved in understanding other people. While most studies employ explicit instructions to learn from social cues, everyday life is characterized by the spontaneous use of such signals (e.g., the gaze of others) to infer on internal states such as intentions. To investigate the neural mechanisms of the impact of gaze cues on learning and decision-making, we acquired behavioural and fMRI data from 50 participants performing a probabilistic task, in which cards with varying winning probabilities had to be chosen. In addition, the task included a computer-generated face that gazed towards one of these cards providing implicit advice. Participants' individual belief trajectories were inferred using a hierarchical Gaussian filter (HGF) and used as predictors in a linear model of neuronal activation. During learning, social prediction errors were correlated with activity in inferior frontal gyrus and insula. During decision-making, the belief about the accuracy of the social cue was correlated with activity in inferior temporal gyrus, putamen and pallidum while the putamen and insula showed activity as a function of individual differences in weighting the social cue during decision-making. Our findings demonstrate that model-based fMRI can give insight into the behavioural and neural aspects of spontaneous social cue integration in learning and decision-making. They provide evidence for a mechanistic involvement of specific components of the basal ganglia in subserving these processes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Computational models of social learning and decision-making provide mechanistic tools to investigate the neural mechanisms that are involved in understanding other people. While most studies employ explicit instructions to learn from social cues, everyday life is characterized by the spontaneous use of such signals (e.g., the gaze of others) to infer on internal states such as intentions. To investigate the neural mechanisms of the impact of gaze cues on learning and decision-making, we acquired behavioural and fMRI data from 50 participants performing a probabilistic task, in which cards with varying winning probabilities had to be chosen. In addition, the task included a computer-generated face that gazed towards one of these cards providing implicit advice. Participants' individual belief trajectories were inferred using a hierarchical Gaussian filter (HGF) and used as predictors in a linear model of neuronal activation. During learning, social prediction errors were correlated with activity in inferior frontal gyrus and insula. During decision-making, the belief about the accuracy of the social cue was correlated with activity in inferior temporal gyrus, putamen and pallidum while the putamen and insula showed activity as a function of individual differences in weighting the social cue during decision-making. Our findings demonstrate that model-based fMRI can give insight into the behavioural and neural aspects of spontaneous social cue integration in learning and decision-making. They provide evidence for a mechanistic involvement of specific components of the basal ganglia in subserving these processes. |
John M Henderson; Wonil Choi; Steven G Luke Morphology of primary visual cortex predicts individual differences in fixation duration during text reading Journal Article Journal of Cognitive Neuroscience, 26 (12), pp. 2880–2888, 2014. @article{Henderson2014a, title = {Morphology of primary visual cortex predicts individual differences in fixation duration during text reading}, author = {John M Henderson and Wonil Choi and Steven G Luke}, doi = {10.1162/jocn_a_00668}, year = {2014}, date = {2014-01-01}, journal = {Journal of Cognitive Neuroscience}, volume = {26}, number = {12}, pages = {2880--2888}, abstract = {In skilled reading, fixations are brief periods of time in which the eyes settle on words. E-Z Reader, a computational model of dynamic reading, posits that fixation durations are under realtime control of lexical processing. Lexical processing, in turn, requires efficient visual encoding. Here we tested the hypothesis that individual differences in fixation durations are related to individual differences in the efficiency of early visual encoding. To test this hypothesis, we recorded participantsʼ eye movements during reading. We then examined individual differences in fixation duration distributions as a function of individual differences in the morphology of primary visual cortex measured from MRI scans. The results showed that greater gray matter surface area and volume in visual cortex predicted shorter and less variable fixation durations in reading. These results suggest that individual differences in eye movements during skilled reading are related to initial visual encoding, consistent with models such as E-Z Reader that emphasize lexical control over fixation time.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In skilled reading, fixations are brief periods of time in which the eyes settle on words. E-Z Reader, a computational model of dynamic reading, posits that fixation durations are under realtime control of lexical processing. Lexical processing, in turn, requires efficient visual encoding. Here we tested the hypothesis that individual differences in fixation durations are related to individual differences in the efficiency of early visual encoding. To test this hypothesis, we recorded participantsʼ eye movements during reading. We then examined individual differences in fixation duration distributions as a function of individual differences in the morphology of primary visual cortex measured from MRI scans. The results showed that greater gray matter surface area and volume in visual cortex predicted shorter and less variable fixation durations in reading. These results suggest that individual differences in eye movements during skilled reading are related to initial visual encoding, consistent with models such as E-Z Reader that emphasize lexical control over fixation time. |
John M Henderson; Wonil Choi Neural correlates of fixation duration during real-world scene viewing: Evidence from fixation-related (FIRE) fMRI Journal Article Journal of Cognitive Neuroscience, 27 (6), pp. 1137–1145, 2015. @article{Henderson2015, title = {Neural correlates of fixation duration during real-world scene viewing: Evidence from fixation-related (FIRE) fMRI}, author = {John M Henderson and Wonil Choi}, doi = {10.1162/jocn}, year = {2015}, date = {2015-01-01}, journal = {Journal of Cognitive Neuroscience}, volume = {27}, number = {6}, pages = {1137--1145}, abstract = {During active scene perception, our eyes move from one location to another via saccadic eye movements, with the eyes fixating objects and scene elements for varying amounts of time. Much of the variability in fixation duration is accounted for by attentional, perceptual, and cognitive processes associated with scene analysis and comprehension. For this reason, current theories of active scene viewing attempt to account for the influence of attention and cognition on fixation duration. Yet almost nothing is known about the neurocognitive systems associated with variation in fixation duration during scene viewing. We addressed this topic using fixation-related fMRI, which involves coregistering high-resolution eye tracking and magnetic resonance scanning to conduct event-related fMRI analysis based on characteristics of eye movements. We observed that activation in visual and prefrontal executive control areas was positively correlated with fixation duration, whereas activation in ventral areas associated with scene en- coding and medial superior frontal and paracentral regions associated with changing action plans was negatively correlated with fixation duration. The results suggest that fixation duration in scene viewing is controlled by cognitive processes associated with real-time scene analysis interacting with motor planning, consistent with current computational models of active vision for scene perception.}, keywords = {}, pubstate = {published}, tppubtype = {article} } During active scene perception, our eyes move from one location to another via saccadic eye movements, with the eyes fixating objects and scene elements for varying amounts of time. Much of the variability in fixation duration is accounted for by attentional, perceptual, and cognitive processes associated with scene analysis and comprehension. For this reason, current theories of active scene viewing attempt to account for the influence of attention and cognition on fixation duration. Yet almost nothing is known about the neurocognitive systems associated with variation in fixation duration during scene viewing. We addressed this topic using fixation-related fMRI, which involves coregistering high-resolution eye tracking and magnetic resonance scanning to conduct event-related fMRI analysis based on characteristics of eye movements. We observed that activation in visual and prefrontal executive control areas was positively correlated with fixation duration, whereas activation in ventral areas associated with scene en- coding and medial superior frontal and paracentral regions associated with changing action plans was negatively correlated with fixation duration. The results suggest that fixation duration in scene viewing is controlled by cognitive processes associated with real-time scene analysis interacting with motor planning, consistent with current computational models of active vision for scene perception. |
John M Henderson; Wonil Choi; Steven G Luke; Rutvik H Desai Neural correlates of fixation duration in natural reading: Evidence from fixation-related fMRI Journal Article NeuroImage, 119 , pp. 390–397, 2015. @article{Henderson2015a, title = {Neural correlates of fixation duration in natural reading: Evidence from fixation-related fMRI}, author = {John M Henderson and Wonil Choi and Steven G Luke and Rutvik H Desai}, doi = {10.1016/j.neuroimage.2015.06.072}, year = {2015}, date = {2015-01-01}, journal = {NeuroImage}, volume = {119}, pages = {390--397}, publisher = {Elsevier Inc.}, abstract = {A key assumption of current theories of natural reading is that fixation duration reflects underlying attentional, language, and cognitive processes associated with text comprehension. The neurocognitive correlates of this relationship are currently unknown. To investigate this relationship, we compared neural activation associated with fixation duration in passage reading and a pseudo-reading control condition. The results showed that fixation duration was associated with activation in oculomotor and language areas during text reading. Fixation duration during pseudo-reading, on the other hand, showed greater involvement of frontal control regions, suggesting flexibility and task dependency of the eye movement network. Consistent with current models, these results provide support for the hypothesis that fixation duration in reading reflects attentional engagement and language processing. The results also demonstrate that fixation-related fMRI provides a method for investigating the neurocognitive bases of natural reading.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A key assumption of current theories of natural reading is that fixation duration reflects underlying attentional, language, and cognitive processes associated with text comprehension. The neurocognitive correlates of this relationship are currently unknown. To investigate this relationship, we compared neural activation associated with fixation duration in passage reading and a pseudo-reading control condition. The results showed that fixation duration was associated with activation in oculomotor and language areas during text reading. Fixation duration during pseudo-reading, on the other hand, showed greater involvement of frontal control regions, suggesting flexibility and task dependency of the eye movement network. Consistent with current models, these results provide support for the hypothesis that fixation duration in reading reflects attentional engagement and language processing. The results also demonstrate that fixation-related fMRI provides a method for investigating the neurocognitive bases of natural reading. |
John M Henderson; Wonil Choi; Matthew W Lowder; Fernanda Ferreira Language structure in the brain: A fixation-related fMRI study of syntactic surprisal in reading Journal Article NeuroImage, 132 , pp. 293–300, 2016. @article{Henderson2016, title = {Language structure in the brain: A fixation-related fMRI study of syntactic surprisal in reading}, author = {John M Henderson and Wonil Choi and Matthew W Lowder and Fernanda Ferreira}, doi = {10.1016/j.neuroimage.2016.02.050}, year = {2016}, date = {2016-01-01}, journal = {NeuroImage}, volume = {132}, pages = {293--300}, publisher = {Elsevier Inc.}, abstract = {How is syntactic analysis implemented by the human brain during language comprehension? The current study combined methods from computational linguistics, eyetracking, and fMRI to address this question. Subjects read passages of text presented as paragraphs while their eye movements were recorded in an MRI scanner. We parsed the text using a probabilistic context-free grammar to isolate syntactic difficulty. Syntactic difficulty was quantified as syntactic surprisal, which is related to the expectedness of a given word's syntactic category given its preceding context. We compared words with high and low syntactic surprisal values that were equated for length, frequency, and lexical surprisal, and used fixation-related (FIRE) fMRI to measure neural activity associated with syntactic surprisal for each fixated word. We observed greater neural activity for high than low syntactic surprisal in two predicted cortical regions previously identified with syntax: left inferior frontal gyrus (IFG) and less robustly, left anterior superior temporal lobe (ATL). These results support the hypothesis that left IFG and ATL play a central role in syntactic analysis during language comprehension. More generally, the results suggest a broader cortical network associated with syntactic prediction that includes increased activity in bilateral IFG and insula, as well as fusiform and right lingual gyri.}, keywords = {}, pubstate = {published}, tppubtype = {article} } How is syntactic analysis implemented by the human brain during language comprehension? The current study combined methods from computational linguistics, eyetracking, and fMRI to address this question. Subjects read passages of text presented as paragraphs while their eye movements were recorded in an MRI scanner. We parsed the text using a probabilistic context-free grammar to isolate syntactic difficulty. Syntactic difficulty was quantified as syntactic surprisal, which is related to the expectedness of a given word's syntactic category given its preceding context. We compared words with high and low syntactic surprisal values that were equated for length, frequency, and lexical surprisal, and used fixation-related (FIRE) fMRI to measure neural activity associated with syntactic surprisal for each fixated word. We observed greater neural activity for high than low syntactic surprisal in two predicted cortical regions previously identified with syntax: left inferior frontal gyrus (IFG) and less robustly, left anterior superior temporal lobe (ATL). These results support the hypothesis that left IFG and ATL play a central role in syntactic analysis during language comprehension. More generally, the results suggest a broader cortical network associated with syntactic prediction that includes increased activity in bilateral IFG and insula, as well as fusiform and right lingual gyri. |
John M Henderson; Wonil Choi; Steven G Luke; Joseph Schmidt Neural correlates of individual differences in fixation duration during natural reading Journal Article Quarterly Journal of Experimental Psychology, 71 (1), pp. 314–323, 2018. @article{Henderson2018, title = {Neural correlates of individual differences in fixation duration during natural reading}, author = {John M Henderson and Wonil Choi and Steven G Luke and Joseph Schmidt}, doi = {10.1080/17470218.2017.1329322}, year = {2018}, date = {2018-01-01}, journal = {Quarterly Journal of Experimental Psychology}, volume = {71}, number = {1}, pages = {314--323}, abstract = {Reading requires integration of language and cognitive processes with attention and eye movement control. Individuals differ in their reading ability, but little is known about the neurocognitive processes associated with these individual differences. To investigate this issue, we combined eyetracking and functional magnetic resonance imaging (fMRI), simultaneously recording eye movements and blood oxygen level dependent (BOLD) activity while subjects read text passages. We found that the variability and skew of fixation duration distributions across individuals, as assessed by ex-Gaussian analyses, decreased with increasing neural activity in regions associated with the cortical eye movement control network (left frontal eye fields [FEF], left intraparietal sulcus [IPS] , left inferior frontal gyrus [IFG] and right IFG). The results suggest that individual differences in fixation duration during reading are related to underlying neurocognitive processes associated with the eye movement control system and its relationship to language processing. The results also show that eye movements and fMRI can be combined to investigate the neural correlates of individual differences in natural reading.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Reading requires integration of language and cognitive processes with attention and eye movement control. Individuals differ in their reading ability, but little is known about the neurocognitive processes associated with these individual differences. To investigate this issue, we combined eyetracking and functional magnetic resonance imaging (fMRI), simultaneously recording eye movements and blood oxygen level dependent (BOLD) activity while subjects read text passages. We found that the variability and skew of fixation duration distributions across individuals, as assessed by ex-Gaussian analyses, decreased with increasing neural activity in regions associated with the cortical eye movement control network (left frontal eye fields [FEF], left intraparietal sulcus [IPS] , left inferior frontal gyrus [IFG] and right IFG). The results suggest that individual differences in fixation duration during reading are related to underlying neurocognitive processes associated with the eye movement control system and its relationship to language processing. The results also show that eye movements and fMRI can be combined to investigate the neural correlates of individual differences in natural reading. |
John M Henderson; Jessica E Goold; Wonil Choi; Taylor R Hayes Neural correlates of fixated low-and high-level scene properties during active scene viewing Journal Article Journal of Cognitive Neuroscience, 32 (10), pp. 2013–2023, 2020. @article{Henderson2020, title = {Neural correlates of fixated low-and high-level scene properties during active scene viewing}, author = {John M Henderson and Jessica E Goold and Wonil Choi and Taylor R Hayes}, doi = {10.1162/jocn_a_01599}, year = {2020}, date = {2020-01-01}, journal = {Journal of Cognitive Neuroscience}, volume = {32}, number = {10}, pages = {2013--2023}, abstract = {During real-world scene perception, viewers actively direct their attention through a scene in a controlled sequence of eye fixations. During each fixation, local scene properties are attended, analyzed, and interpreted. What is the relationship between fixated scene properties and neural activity in the visual cortex? Participants inspected photographs of real-world scenes in an MRI scanner while their eye movements were recorded. Fixation-related fMRI was used tomeasure activation as a function of lower- and higher-level scene properties at fixation, operationalized as edge density and meaning maps, respectively. We found that edge density at fixation was most associated with activation in early visual areas, whereas semantic content at fixation was most associated with activation along the ventral visual streamincluding core object and scene-selective areas (lateral occipital complex, parahippocampal place area, occipital place area, and retrosplenial cortex). The observed activation from semantic content was not accounted for by differences in edge density. The results are consistent with active vision models in which fixation gates detailed visual analysis for fixated scene regions, and this gating influences both lower and higher levels of scene analysis.}, keywords = {}, pubstate = {published}, tppubtype = {article} } During real-world scene perception, viewers actively direct their attention through a scene in a controlled sequence of eye fixations. During each fixation, local scene properties are attended, analyzed, and interpreted. What is the relationship between fixated scene properties and neural activity in the visual cortex? Participants inspected photographs of real-world scenes in an MRI scanner while their eye movements were recorded. Fixation-related fMRI was used tomeasure activation as a function of lower- and higher-level scene properties at fixation, operationalized as edge density and meaning maps, respectively. We found that edge density at fixation was most associated with activation in early visual areas, whereas semantic content at fixation was most associated with activation along the ventral visual streamincluding core object and scene-selective areas (lateral occipital complex, parahippocampal place area, occipital place area, and retrosplenial cortex). The observed activation from semantic content was not accounted for by differences in edge density. The results are consistent with active vision models in which fixation gates detailed visual analysis for fixated scene regions, and this gating influences both lower and higher levels of scene analysis. |
Linda Henriksson; Marieke Mur; Nikolaus Kriegeskorte Rapid invariant encoding of scene layout in human OPA Journal Article Neuron, 103 , pp. 161–171, 2019. @article{Henriksson2019, title = {Rapid invariant encoding of scene layout in human OPA}, author = {Linda Henriksson and Marieke Mur and Nikolaus Kriegeskorte}, doi = {10.1016/j.neuron.2019.04.014}, year = {2019}, date = {2019-01-01}, journal = {Neuron}, volume = {103}, pages = {161--171}, publisher = {Elsevier Inc.}, abstract = {Successful visual navigation requires a sense of the geometry of the local environment. How do our brains extract this information from retinal images? Here we visually presented scenes with all possible combinations of five scene-bounding elements (left, right, and back walls; ceiling; floor) to human subjects during functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG). The fMRI response patterns in the scene-responsive occipital place area (OPA) reflected scene layout with invariance to changes in surface texture. This result contrasted sharply with the primary visual cortex (V1), which reflected low-level image features of the stimuli, and the parahippocampal place area (PPA), which showed better texture than layout decoding. MEG indicated that the texture-invariant scene layout representation is computed from visual input within ∼100 ms, suggesting a rapid computational mechanism. Taken together, these results suggest that the cortical representation underlying our instant sense of the environmental geometry is located in the OPA.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Successful visual navigation requires a sense of the geometry of the local environment. How do our brains extract this information from retinal images? Here we visually presented scenes with all possible combinations of five scene-bounding elements (left, right, and back walls; ceiling; floor) to human subjects during functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG). The fMRI response patterns in the scene-responsive occipital place area (OPA) reflected scene layout with invariance to changes in surface texture. This result contrasted sharply with the primary visual cortex (V1), which reflected low-level image features of the stimuli, and the parahippocampal place area (PPA), which showed better texture than layout decoding. MEG indicated that the texture-invariant scene layout representation is computed from visual input within ∼100 ms, suggesting a rapid computational mechanism. Taken together, these results suggest that the cortical representation underlying our instant sense of the environmental geometry is located in the OPA. |
Erno J Hermans; Jonathan W Kanen; Arielle Tambini; Guillén Fernández; Lila Davachi; Elizabeth A Phelps Cerebral Cortex, 27 (5), pp. 3028–3041, 2017. @article{Hermans2017, title = {Persistence of amygdala-hippocampal connectivity and multi-voxel correlation structures during awake rest after fear learning predicts long-term expression of fear}, author = {Erno J Hermans and Jonathan W Kanen and Arielle Tambini and Guillén Fernández and Lila Davachi and Elizabeth A Phelps}, doi = {10.1093/cercor/bhw145}, year = {2017}, date = {2017-01-01}, journal = {Cerebral Cortex}, volume = {27}, number = {5}, pages = {3028--3041}, abstract = {After encoding, memories undergo a process of consolidation that determines long-term retention. For conditioned fear, animal models postulate that consolidation involves reactivations of neuronal assemblies supporting fear learning during postlearning " offline " periods. However, no human studies to date have investigated such processes, particularly in relation to long-term expression of fear. We tested 24 participants using functional MRI on 2 consecutive days in a fear conditioning paradigm involving 1 habituation block, 2 acquisition blocks, and 2 extinction blocks on day 1, and 2 re-extinction blocks on day 2. Conditioning blocks were preceded and followed by 4.5-min rest blocks. Strength of spontaneous recovery of fear on day 2 served as a measure of long-term expression of fear. Amygdala connectivity primarily with hippocampus increased progressively during postacquisition and postextinction rest on day 1. Intraregional multi-voxel correlation structures within amygdala and hippocampus sampled during a block of differential fear conditioning furthermore persisted after fear learning. Critically, both these main findings were stronger in participants who exhibited spontaneous recovery 24 h later. Our findings indicate that neural circuits activated during fear conditioning exhibit persistent postlearning activity that may be functionally relevant in promoting consolidation of the fear memory.}, keywords = {}, pubstate = {published}, tppubtype = {article} } After encoding, memories undergo a process of consolidation that determines long-term retention. For conditioned fear, animal models postulate that consolidation involves reactivations of neuronal assemblies supporting fear learning during postlearning " offline " periods. However, no human studies to date have investigated such processes, particularly in relation to long-term expression of fear. We tested 24 participants using functional MRI on 2 consecutive days in a fear conditioning paradigm involving 1 habituation block, 2 acquisition blocks, and 2 extinction blocks on day 1, and 2 re-extinction blocks on day 2. Conditioning blocks were preceded and followed by 4.5-min rest blocks. Strength of spontaneous recovery of fear on day 2 served as a measure of long-term expression of fear. Amygdala connectivity primarily with hippocampus increased progressively during postacquisition and postextinction rest on day 1. Intraregional multi-voxel correlation structures within amygdala and hippocampus sampled during a block of differential fear conditioning furthermore persisted after fear learning. Critically, both these main findings were stronger in participants who exhibited spontaneous recovery 24 h later. Our findings indicate that neural circuits activated during fear conditioning exhibit persistent postlearning activity that may be functionally relevant in promoting consolidation of the fear memory. |
Jim D Herring; Sophie Esterer; Tom R Marshall; Ole Jensen; Til O Bergmann Low-frequency alternating current stimulation rhythmically suppresses gamma-band oscillations and impairs perceptual performance Journal Article NeuroImage, 184 , pp. 440–449, 2019. @article{Herring2019, title = {Low-frequency alternating current stimulation rhythmically suppresses gamma-band oscillations and impairs perceptual performance}, author = {Jim D Herring and Sophie Esterer and Tom R Marshall and Ole Jensen and Til O Bergmann}, doi = {10.1016/j.neuroimage.2018.09.047}, year = {2019}, date = {2019-01-01}, journal = {NeuroImage}, volume = {184}, pages = {440--449}, publisher = {Elsevier Ltd}, abstract = {Low frequency oscillations such as alpha (8–12 Hz) are hypothesized to rhythmically gate sensory processing, reflected by 40–100 Hz gamma band activity, via the mechanism of pulsed inhibition. We applied transcranial alternating current stimulation (TACS) at individual alpha frequency (IAF) and flanking frequencies (IAF-4 Hz, IAF+4 Hz) to the occipital cortex of healthy human volunteers during concurrent magnetoencephalography (MEG), while participants performed a visual detection task inducing strong gamma-band responses. Occipital (but not retinal) TACS phasically suppressed stimulus-induced gamma oscillations in the visual cortex and impaired target detection, with stronger phase-to-amplitude coupling predicting behavioral impairments. Retinal control TACS ruled out retino-thalamo-cortical entrainment resulting from (subthreshold) retinal stimulation. All TACS frequencies tested were effective, suggesting that visual gamma-band responses can be modulated by a range of low frequency oscillations. We propose that TACS-induced membrane potential modulations mimic the rhythmic change in cortical excitability by which spontaneous low frequency oscillations may eventually exert their impact when gating sensory processing via pulsed inhibition.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Low frequency oscillations such as alpha (8–12 Hz) are hypothesized to rhythmically gate sensory processing, reflected by 40–100 Hz gamma band activity, via the mechanism of pulsed inhibition. We applied transcranial alternating current stimulation (TACS) at individual alpha frequency (IAF) and flanking frequencies (IAF-4 Hz, IAF+4 Hz) to the occipital cortex of healthy human volunteers during concurrent magnetoencephalography (MEG), while participants performed a visual detection task inducing strong gamma-band responses. Occipital (but not retinal) TACS phasically suppressed stimulus-induced gamma oscillations in the visual cortex and impaired target detection, with stronger phase-to-amplitude coupling predicting behavioral impairments. Retinal control TACS ruled out retino-thalamo-cortical entrainment resulting from (subthreshold) retinal stimulation. All TACS frequencies tested were effective, suggesting that visual gamma-band responses can be modulated by a range of low frequency oscillations. We propose that TACS-induced membrane potential modulations mimic the rhythmic change in cortical excitability by which spontaneous low frequency oscillations may eventually exert their impact when gating sensory processing via pulsed inhibition. |
Katrin Herrmann; Leila Montaser-Kouhsari; Marisa Carrasco; David J Heeger When size matters: Attention affects performance by contrast or response gain Journal Article Nature Neuroscience, 13 (12), pp. 1554–1561, 2010. @article{Herrmann2010, title = {When size matters: Attention affects performance by contrast or response gain}, author = {Katrin Herrmann and Leila Montaser-Kouhsari and Marisa Carrasco and David J Heeger}, doi = {10.1038/nn.2669}, year = {2010}, date = {2010-01-01}, journal = {Nature Neuroscience}, volume = {13}, number = {12}, pages = {1554--1561}, publisher = {Nature Publishing Group}, abstract = {Covert attention, the selective processing of visual information in the absence of eye movements, improves behavioral performance. Here, we show that attention, both exogenous (involuntary) and endogenous (voluntary), can affect performance by contrast or response gain changes, depending on the stimulus size and the relative size of the attention field. These two variables were manipulated in a cueing task while varying stimulus contrast. We observed a change in behavioral performance consonant with a change in contrast gain for small stimuli paired with spatial uncertainty, but a change in response gain for large stimuli presented at one location (no uncertainty) and surrounded by irrelevant flanking distracters. A complementary neuroimaging experiment revealed that observers' attention field was wider with than without spatial uncertainty. Our results support key predictions of the normalization model of attention, and reconcile previous, seemingly contradictory, findings on the effects of visual attention. Introduction}, keywords = {}, pubstate = {published}, tppubtype = {article} } Covert attention, the selective processing of visual information in the absence of eye movements, improves behavioral performance. Here, we show that attention, both exogenous (involuntary) and endogenous (voluntary), can affect performance by contrast or response gain changes, depending on the stimulus size and the relative size of the attention field. These two variables were manipulated in a cueing task while varying stimulus contrast. We observed a change in behavioral performance consonant with a change in contrast gain for small stimuli paired with spatial uncertainty, but a change in response gain for large stimuli presented at one location (no uncertainty) and surrounded by irrelevant flanking distracters. A complementary neuroimaging experiment revealed that observers' attention field was wider with than without spatial uncertainty. Our results support key predictions of the normalization model of attention, and reconcile previous, seemingly contradictory, findings on the effects of visual attention. Introduction |
Nora A Herweg; Bernd Weber; Anna-Maria Kasparbauer; Inga Meyhöfer; Maria Steffens; Nikolaos Smyrnis; Ulrich Ettinger Functional magnetic resonance imaging of sensorimotor transformations in saccades and antisaccades Journal Article NeuroImage, 102 , pp. 848–860, 2014. @article{Herweg2014, title = {Functional magnetic resonance imaging of sensorimotor transformations in saccades and antisaccades}, author = {Nora A Herweg and Bernd Weber and Anna-Maria Kasparbauer and Inga Meyhöfer and Maria Steffens and Nikolaos Smyrnis and Ulrich Ettinger}, doi = {10.1016/j.neuroimage.2014.08.033}, year = {2014}, date = {2014-01-01}, journal = {NeuroImage}, volume = {102}, pages = {848--860}, abstract = {Saccades to peripheral targets require a direct visuomotor transformation. In contrast, antisaccades, saccades in opposite direction of a peripheral target, require more complex transformation processes due to the inversion of the spatial vector. Here, the differential neural mechanisms underlying sensorimotor control in saccades and antisaccades were investigated using functional magnetic resonance imaging (fMRI) at 3. T field strength in 22 human volunteers. We combined a task factor (prosaccades: look towards target; antisaccades: look away from target) with a parametric factor of transformation demand (single vs. multiple peripheral targets) in a two-factorial block design. Behaviorally, a greater number of peripheral targets resulted in decreased spatial accuracy and increased reaction times in antisaccades. No effects were seen on the percentage of antisaccade direction errors or on any prosaccade measures. Neurally, a greater number of targets led to increased BOLD signal in the posterior parietal cortex (PPC) bilaterally. This effect was partially qualified by an interaction that extended into somatosensory cortex, indicating greater increases during antisaccades than prosaccades. The results implicate the PPC as a sensorimotor interface that is especially important in nonstandard mapping for antisaccades and point to a supportive role of somatosensory areas in antisaccade sensorimotor control, possibly by means of proprioceptive processes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Saccades to peripheral targets require a direct visuomotor transformation. In contrast, antisaccades, saccades in opposite direction of a peripheral target, require more complex transformation processes due to the inversion of the spatial vector. Here, the differential neural mechanisms underlying sensorimotor control in saccades and antisaccades were investigated using functional magnetic resonance imaging (fMRI) at 3. T field strength in 22 human volunteers. We combined a task factor (prosaccades: look towards target; antisaccades: look away from target) with a parametric factor of transformation demand (single vs. multiple peripheral targets) in a two-factorial block design. Behaviorally, a greater number of peripheral targets resulted in decreased spatial accuracy and increased reaction times in antisaccades. No effects were seen on the percentage of antisaccade direction errors or on any prosaccade measures. Neurally, a greater number of targets led to increased BOLD signal in the posterior parietal cortex (PPC) bilaterally. This effect was partially qualified by an interaction that extended into somatosensory cortex, indicating greater increases during antisaccades than prosaccades. The results implicate the PPC as a sensorimotor interface that is especially important in nonstandard mapping for antisaccades and point to a supportive role of somatosensory areas in antisaccade sensorimotor control, possibly by means of proprioceptive processes. |
Nora A Herweg; Tobias Sommer; Nico Bunzeck Retrieval demands adaptively change striatal old/new signals and boost subsequent long-term memory Journal Article Journal of Neuroscience, 38 (3), pp. 745–754, 2018. @article{Herweg2018, title = {Retrieval demands adaptively change striatal old/new signals and boost subsequent long-term memory}, author = {Nora A Herweg and Tobias Sommer and Nico Bunzeck}, doi = {10.1523/jneurosci.1315-17.2017}, year = {2018}, date = {2018-01-01}, journal = {Journal of Neuroscience}, volume = {38}, number = {3}, pages = {745--754}, abstract = {The striatum is a central part of the dopaminergic mesolimbic system and contributes both to the encoding and retrieval of long-term memories. In this regard, the co-occurrence of striatal novelty and retrieval success effects in independent studies underlines the structure's double duty and suggests dynamic contextual adaptation. To test this hypothesis and further investigate the underlying mechanisms ofencoding and retrieval dynamics, human subjects viewed pre-familiarized scene images intermixed with new scenes and classified them as indoor versus outdoor (encoding task) or old versus new (retrieval task), while fMRI and eye tracking data were recorded. Subsequently, subjects performed a final recognition task. As hypothesized, striatal activity and pupil size reflected task- conditional salience ofold and new stimuli, but, unexpectedly, this effect was not reflected in the substantia nigra and ventral tegmental area (SN/VTA), medial temporal lobe, or subsequent memory performance. Instead, subsequent memory generally benefitted from retrieval, an effect possibly driven by task difficulty and activity in a network including different parts ofthe striatum and SN/VTA. Our findings extend memory models of encoding and retrieval dynamics by pinpointing a specific contextual factor that differentially modulates the functional properties ofthe mesolimbic system.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The striatum is a central part of the dopaminergic mesolimbic system and contributes both to the encoding and retrieval of long-term memories. In this regard, the co-occurrence of striatal novelty and retrieval success effects in independent studies underlines the structure's double duty and suggests dynamic contextual adaptation. To test this hypothesis and further investigate the underlying mechanisms ofencoding and retrieval dynamics, human subjects viewed pre-familiarized scene images intermixed with new scenes and classified them as indoor versus outdoor (encoding task) or old versus new (retrieval task), while fMRI and eye tracking data were recorded. Subsequently, subjects performed a final recognition task. As hypothesized, striatal activity and pupil size reflected task- conditional salience ofold and new stimuli, but, unexpectedly, this effect was not reflected in the substantia nigra and ventral tegmental area (SN/VTA), medial temporal lobe, or subsequent memory performance. Instead, subsequent memory generally benefitted from retrieval, an effect possibly driven by task difficulty and activity in a network including different parts ofthe striatum and SN/VTA. Our findings extend memory models of encoding and retrieval dynamics by pinpointing a specific contextual factor that differentially modulates the functional properties ofthe mesolimbic system. |
Jörn M Horschig; Ole Jensen; Martine R van Schouwenburg; Roshan Cools; Mathilde Bonnefond Alpha activity reflects individual abilities to adapt to the environment Journal Article NeuroImage, 89 , pp. 235–243, 2014. @article{Horschig2014, title = {Alpha activity reflects individual abilities to adapt to the environment}, author = {Jörn M Horschig and Ole Jensen and Martine R van Schouwenburg and Roshan Cools and Mathilde Bonnefond}, doi = {10.1016/j.neuroimage.2013.12.018}, year = {2014}, date = {2014-01-01}, journal = {NeuroImage}, volume = {89}, pages = {235--243}, publisher = {Elsevier Inc.}, abstract = {Recent findings suggest that oscillatory alpha activity (7-13. Hz) is associated with functional inhibition of sensory regions by filtering incoming information. Accordingly the alpha power in visual regions varies in anticipation of upcoming, predictable stimuli which has consequences for visual processing and subsequent behavior. In covert spatial attention studies it has been demonstrated that performance correlates with the adaptation of alpha power in response to explicit spatial cueing. However it remains unknown whether such an adaptation also occurs in response to implicit statistical properties of a task. In a covert attention switching paradigm, we here show evidence that individuals differ on how they adapt to implicit statistical properties of the task. Subjects whose behavioral performance reflects the implicit change in switch trial likelihood show strong adjustment of anticipatory alpha power lateralization. Most importantly, the stronger the behavioral adjustment to the switch trial likelihood was, the stronger the adjustment of anticipatory posterior alpha lateralization. We conclude that anticipatory spatial attention is reflected in the distribution of posterior alpha band power which is predictive of individual detection performance in response to the implicit statistical properties of the task.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Recent findings suggest that oscillatory alpha activity (7-13. Hz) is associated with functional inhibition of sensory regions by filtering incoming information. Accordingly the alpha power in visual regions varies in anticipation of upcoming, predictable stimuli which has consequences for visual processing and subsequent behavior. In covert spatial attention studies it has been demonstrated that performance correlates with the adaptation of alpha power in response to explicit spatial cueing. However it remains unknown whether such an adaptation also occurs in response to implicit statistical properties of a task. In a covert attention switching paradigm, we here show evidence that individuals differ on how they adapt to implicit statistical properties of the task. Subjects whose behavioral performance reflects the implicit change in switch trial likelihood show strong adjustment of anticipatory alpha power lateralization. Most importantly, the stronger the behavioral adjustment to the switch trial likelihood was, the stronger the adjustment of anticipatory posterior alpha lateralization. We conclude that anticipatory spatial attention is reflected in the distribution of posterior alpha band power which is predictive of individual detection performance in response to the implicit statistical properties of the task. |
Jörn M Horschig; Wouter Oosterheert; Robert Oostenveld; Ole Jensen Modulation of posterior alpha activity by spatial attention allows for controlling a continuous brain–computer interface Journal Article Brain Topography, 28 (6), pp. 852–864, 2015. @article{Horschig2015, title = {Modulation of posterior alpha activity by spatial attention allows for controlling a continuous brain–computer interface}, author = {Jörn M Horschig and Wouter Oosterheert and Robert Oostenveld and Ole Jensen}, doi = {10.1007/s10548-014-0401-7}, year = {2015}, date = {2015-01-01}, journal = {Brain Topography}, volume = {28}, number = {6}, pages = {852--864}, abstract = {Here we report that the modulation of alpha activity by covert attention can be used as a control signal in an online brain-computer interface, that it is reliable, and that it is robust. Subjects were instructed to orient covert visual attention to the left or right hemifield. We decoded the direction of attention from the magnetoencephalogram by a template matching classifier and provided the classification outcome to the subject in real-time using a novel graphical user interface. Training data for the templates were obtained from a Posner-cueing task conducted just before the BCI task. Eleven subjects participated in four sessions each. Eight of the subjects achieved classification rates significantly above chance level. Subjects were able to significantly increase their performance from the first to the second session. Individual patterns of posterior alpha power remained stable throughout the four sessions and did not change with increased performance. We conclude that posterior alpha power can successfully be used as a control signal in brain-computer interfaces. We also discuss several ideas for further improving the setup and propose future research based on solid hypotheses about behavioral consequences of modulating neuronal oscillations by brain computer interfacing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Here we report that the modulation of alpha activity by covert attention can be used as a control signal in an online brain-computer interface, that it is reliable, and that it is robust. Subjects were instructed to orient covert visual attention to the left or right hemifield. We decoded the direction of attention from the magnetoencephalogram by a template matching classifier and provided the classification outcome to the subject in real-time using a novel graphical user interface. Training data for the templates were obtained from a Posner-cueing task conducted just before the BCI task. Eleven subjects participated in four sessions each. Eight of the subjects achieved classification rates significantly above chance level. Subjects were able to significantly increase their performance from the first to the second session. Individual patterns of posterior alpha power remained stable throughout the four sessions and did not change with increased performance. We conclude that posterior alpha power can successfully be used as a control signal in brain-computer interfaces. We also discuss several ideas for further improving the setup and propose future research based on solid hypotheses about behavioral consequences of modulating neuronal oscillations by brain computer interfacing. |
Jaakko Hotta; Jukka Saari; Miika Koskinen; Yevhen Hlushchuk; Nina Forss; Riitta Hari Abnormal brain responses to action observation in complex regional pain syndrome Journal Article Journal of Pain, 18 (3), pp. 255–265, 2017. @article{Hotta2017, title = {Abnormal brain responses to action observation in complex regional pain syndrome}, author = {Jaakko Hotta and Jukka Saari and Miika Koskinen and Yevhen Hlushchuk and Nina Forss and Riitta Hari}, doi = {10.1016/j.jpain.2016.10.017}, year = {2017}, date = {2017-01-01}, journal = {Journal of Pain}, volume = {18}, number = {3}, pages = {255--265}, publisher = {Elsevier Inc}, abstract = {Patients with complex regional pain syndrome (CRPS) display various abnormalities in central motor function, and their pain is intensified when they perform or just observe motor actions. In this study, we examined the abnormalities of brain responses to action observation in CRPS. We analyzed 3-T functional magnetic resonance images from 13 upper limb CRPS patients (all female, ages 31–58 years) and 13 healthy, age- and sex-matched control subjects. The functional magnetic resonance imaging data were acquired while the subjects viewed brief videos of hand actions shown in the first-person perspective. A pattern-classification analysis was applied to characterize brain areas where the activation pattern differed between CRPS patients and healthy subjects. Brain areas with statistically significant group differences (q textless .05, false discovery rate-corrected) included the hand representation area in the sensorimotor cortex, inferior frontal gyrus, secondary somatosensory cortex, inferior parietal lobule, orbitofrontal cortex, and thalamus. Our findings indicate that CRPS impairs action observation by affecting brain areas related to pain processing and motor control. Perspective This article shows that in CRPS, the observation of others' motor actions induces abnormal neural activity in brain areas essential for sensorimotor functions and pain. These results build the cerebral basis for action-observation impairments in CRPS.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Patients with complex regional pain syndrome (CRPS) display various abnormalities in central motor function, and their pain is intensified when they perform or just observe motor actions. In this study, we examined the abnormalities of brain responses to action observation in CRPS. We analyzed 3-T functional magnetic resonance images from 13 upper limb CRPS patients (all female, ages 31–58 years) and 13 healthy, age- and sex-matched control subjects. The functional magnetic resonance imaging data were acquired while the subjects viewed brief videos of hand actions shown in the first-person perspective. A pattern-classification analysis was applied to characterize brain areas where the activation pattern differed between CRPS patients and healthy subjects. Brain areas with statistically significant group differences (q textless .05, false discovery rate-corrected) included the hand representation area in the sensorimotor cortex, inferior frontal gyrus, secondary somatosensory cortex, inferior parietal lobule, orbitofrontal cortex, and thalamus. Our findings indicate that CRPS impairs action observation by affecting brain areas related to pain processing and motor control. Perspective This article shows that in CRPS, the observation of others' motor actions induces abnormal neural activity in brain areas essential for sensorimotor functions and pain. These results build the cerebral basis for action-observation impairments in CRPS. |
Chun-Ting Hsu; Roy Clariana; Benjamin Schloss; Ping Li Neurocognitive signatures of naturalistic reading of scientific texts: A fixation-related fMRI study Journal Article Scientific Reports, 9 , pp. 10678, 2019. @article{Hsu2019, title = {Neurocognitive signatures of naturalistic reading of scientific texts: A fixation-related fMRI study}, author = {Chun-Ting Hsu and Roy Clariana and Benjamin Schloss and Ping Li}, doi = {10.1038/s41598-019-47176-7}, year = {2019}, date = {2019-12-01}, journal = {Scientific Reports}, volume = {9}, pages = {10678}, publisher = {Nature Publishing Group}, abstract = {How do students gain scientific knowledge while reading expository text? This study examines the underlying neurocognitive basis of textual knowledge structure and individual readers' cognitive differences and reading habits, including the influence of text and reader characteristics, on outcomes of scientific text comprehension. By combining fixation-related fMRI and multiband data acquisition, the study is among the first to consider self-paced naturalistic reading inside the MRI scanner. Our results revealed the underlying neurocognitive patterns associated with information integration of different time scales during text reading, and significant individual differences due to the interaction between text characteristics (e.g., optimality of the textual knowledge structure) and reader characteristics (e.g., electronic device use habits). Individual differences impacted the amount of neural resources deployed for multitasking and information integration for constructing the underlying scientific mental models based on the text being read. Our findings have significant implications for understanding science reading in a population that is increasingly dependent on electronic devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } How do students gain scientific knowledge while reading expository text? This study examines the underlying neurocognitive basis of textual knowledge structure and individual readers' cognitive differences and reading habits, including the influence of text and reader characteristics, on outcomes of scientific text comprehension. By combining fixation-related fMRI and multiband data acquisition, the study is among the first to consider self-paced naturalistic reading inside the MRI scanner. Our results revealed the underlying neurocognitive patterns associated with information integration of different time scales during text reading, and significant individual differences due to the interaction between text characteristics (e.g., optimality of the textual knowledge structure) and reader characteristics (e.g., electronic device use habits). Individual differences impacted the amount of neural resources deployed for multitasking and information integration for constructing the underlying scientific mental models based on the text being read. Our findings have significant implications for understanding science reading in a population that is increasingly dependent on electronic devices. |
Anna E Hughes; John A Greenwood; Nonie J Finlayson; Samuel D Schwarzkopf Population receptive field estimates for motion-defined stimuli Journal Article NeuroImage, 199 , pp. 245–260, 2019. @article{Hughes2019, title = {Population receptive field estimates for motion-defined stimuli}, author = {Anna E Hughes and John A Greenwood and Nonie J Finlayson and Samuel D Schwarzkopf}, doi = {10.1016/j.neuroimage.2019.05.068}, year = {2019}, date = {2019-01-01}, journal = {NeuroImage}, volume = {199}, pages = {245--260}, abstract = {The processing of motion changes throughout the visual hierarchy, from spatially restricted ‘local motion' in early visual cortex to more complex large-field ‘global motion' at later stages. Here we used functional magnetic resonance imaging (fMRI) to examine spatially selective responses in these areas related to the processing of random-dot stimuli defined by differences in motion. We used population receptive field (pRF) analyses to map retinotopic cortex using bar stimuli comprising coherently moving dots. In the first experiment, we used three separate background conditions: no background dots (dot-defined bar-only), dots moving coherently in the opposite direction to the bar (kinetic boundary) and dots moving incoherently in random directions (global motion). Clear retinotopic maps were obtained for the bar-only and kinetic-boundary conditions across visual areas V1–V3 and in higher dorsal areas. For the global-motion condition, retinotopic maps were much weaker in early areas and became clear only in higher areas, consistent with the emergence of global-motion processing throughout the visual hierarchy. However, in a second experiment we demonstrate that this pattern is not specific to motion-defined stimuli, with very similar results for a transparent-motion stimulus and a bar defined by a static low-level property (dot size) that should have driven responses particularly in V1. We further exclude explanations based on stimulus visibility by demonstrating that the observed differences in pRF properties do not follow the ability of observers to localise or attend to these bar elements. Rather, our findings indicate that dorsal extrastriate retinotopic maps may primarily be determined by the visibility of the neural responses to the bar relative to the background response (i.e. neural signal-to-noise ratios) and suggests that claims about stimulus selectivity from pRF experiments must be interpreted with caution.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The processing of motion changes throughout the visual hierarchy, from spatially restricted ‘local motion' in early visual cortex to more complex large-field ‘global motion' at later stages. Here we used functional magnetic resonance imaging (fMRI) to examine spatially selective responses in these areas related to the processing of random-dot stimuli defined by differences in motion. We used population receptive field (pRF) analyses to map retinotopic cortex using bar stimuli comprising coherently moving dots. In the first experiment, we used three separate background conditions: no background dots (dot-defined bar-only), dots moving coherently in the opposite direction to the bar (kinetic boundary) and dots moving incoherently in random directions (global motion). Clear retinotopic maps were obtained for the bar-only and kinetic-boundary conditions across visual areas V1–V3 and in higher dorsal areas. For the global-motion condition, retinotopic maps were much weaker in early areas and became clear only in higher areas, consistent with the emergence of global-motion processing throughout the visual hierarchy. However, in a second experiment we demonstrate that this pattern is not specific to motion-defined stimuli, with very similar results for a transparent-motion stimulus and a bar defined by a static low-level property (dot size) that should have driven responses particularly in V1. We further exclude explanations based on stimulus visibility by demonstrating that the observed differences in pRF properties do not follow the ability of observers to localise or attend to these bar elements. Rather, our findings indicate that dorsal extrastriate retinotopic maps may primarily be determined by the visibility of the neural responses to the bar relative to the background response (i.e. neural signal-to-noise ratios) and suggests that claims about stimulus selectivity from pRF experiments must be interpreted with caution. |
A Hummer; M Ritter; M Tik; A A Ledolter; M Woletz; G E Holder; Serge O Dumoulin; U Schmidt-Erfurth; C Windischberger Eyetracker-based gaze correction for robust mapping of population receptive fields Journal Article NeuroImage, 142 , pp. 211–224, 2016. @article{Hummer2016, title = {Eyetracker-based gaze correction for robust mapping of population receptive fields}, author = {A Hummer and M Ritter and M Tik and A A Ledolter and M Woletz and G E Holder and Serge O Dumoulin and U Schmidt-Erfurth and C Windischberger}, doi = {10.1016/j.neuroimage.2016.07.003}, year = {2016}, date = {2016-01-01}, journal = {NeuroImage}, volume = {142}, pages = {211--224}, publisher = {Elsevier B.V.}, abstract = {Functional MRI enables the acquisition of a retinotopic map that relates regions of the visual field to neural populations in the visual cortex. During such a “population receptive field” (PRF) experiment, stable gaze fixation is of utmost importance in order to correctly link the presented stimulus patterns to stimulated retinal regions and the resulting Blood Oxygen Level Dependent (BOLD) response of the appropriate region within the visual cortex. A method is described that compensates for unstable gaze fixation by recording gaze position via an eyetracker and subsequently modifies the input stimulus underlying the PRF analysis according to the eyetracking measures. Here we show that PRF maps greatly improve when the method is applied to data acquired with either saccadic or smooth eye movements. We conclude that the technique presented herein is useful for studies involving subjects with unstable gaze fixation, particularly elderly patient populations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Functional MRI enables the acquisition of a retinotopic map that relates regions of the visual field to neural populations in the visual cortex. During such a “population receptive field” (PRF) experiment, stable gaze fixation is of utmost importance in order to correctly link the presented stimulus patterns to stimulated retinal regions and the resulting Blood Oxygen Level Dependent (BOLD) response of the appropriate region within the visual cortex. A method is described that compensates for unstable gaze fixation by recording gaze position via an eyetracker and subsequently modifies the input stimulus underlying the PRF analysis according to the eyetracking measures. Here we show that PRF maps greatly improve when the method is applied to data acquired with either saccadic or smooth eye movements. We conclude that the technique presented herein is useful for studies involving subjects with unstable gaze fixation, particularly elderly patient populations. |
Akiko Ikkai; Sangita Dandekar; Clayton E Curtis Lateralization in alpha-band oscillations predicts the locus and spatial distribution of attention Journal Article PLoS ONE, 11 (5), pp. e0154796, 2016. @article{Ikkai2016, title = {Lateralization in alpha-band oscillations predicts the locus and spatial distribution of attention}, author = {Akiko Ikkai and Sangita Dandekar and Clayton E Curtis}, doi = {10.1371/journal.pone.0154796}, year = {2016}, date = {2016-01-01}, journal = {PLoS ONE}, volume = {11}, number = {5}, pages = {e0154796}, abstract = {Attending to a task-relevant location changes how neural activity oscillates in the alpha band (8-13Hz) in posterior visual cortical areas. However, a clear understanding of the relationships between top-down attention, changes in alpha oscillations in visual cortex, and attention performance are still poorly understood. Here, we tested the degree to which the posterior alpha power tracked the locus of attention, the distribution of attention, and how well the topography of alpha could predict the locus of attention. We recorded magnetoencephalographic (MEG) data while subjects performed an attention demanding visual discrimination task that dissociated the direction of attention from the direction of a saccade to indicate choice. On some trials, an endogenous cue predicted the target's location, while on others it contained no spatial information. When the target's location was cued, alpha power decreased in sensors over occipital cortex contralateral to the attended visual field. When the cue did not predict the target's location, alpha power again decreased in sensors over occipital cortex, but bilaterally, and increased in sensors over frontal cortex. Thus, the distribution and the topography of alpha reliably indicated the locus of covert attention. Together, these results suggest that alpha synchronization reflects changes in the excitability of populations of neurons whose receptive fields match the locus of attention. This is consistent with the hypothesis that alpha oscillations reflect the neural mechanisms by which top-down control of attention biases information processing and modulate the activity of neurons in visual cortex.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Attending to a task-relevant location changes how neural activity oscillates in the alpha band (8-13Hz) in posterior visual cortical areas. However, a clear understanding of the relationships between top-down attention, changes in alpha oscillations in visual cortex, and attention performance are still poorly understood. Here, we tested the degree to which the posterior alpha power tracked the locus of attention, the distribution of attention, and how well the topography of alpha could predict the locus of attention. We recorded magnetoencephalographic (MEG) data while subjects performed an attention demanding visual discrimination task that dissociated the direction of attention from the direction of a saccade to indicate choice. On some trials, an endogenous cue predicted the target's location, while on others it contained no spatial information. When the target's location was cued, alpha power decreased in sensors over occipital cortex contralateral to the attended visual field. When the cue did not predict the target's location, alpha power again decreased in sensors over occipital cortex, but bilaterally, and increased in sensors over frontal cortex. Thus, the distribution and the topography of alpha reliably indicated the locus of covert attention. Together, these results suggest that alpha synchronization reflects changes in the excitability of populations of neurons whose receptive fields match the locus of attention. This is consistent with the hypothesis that alpha oscillations reflect the neural mechanisms by which top-down control of attention biases information processing and modulate the activity of neurons in visual cortex. |
Elisa Infanti; Samuel D Schwarzkopf Mapping sequences can bias population receptive field estimates Journal Article NeuroImage, 211 , pp. 1–13, 2020. @article{Infanti2020, title = {Mapping sequences can bias population receptive field estimates}, author = {Elisa Infanti and Samuel D Schwarzkopf}, doi = {10.1016/j.neuroimage.2020.116636}, year = {2020}, date = {2020-01-01}, journal = {NeuroImage}, volume = {211}, pages = {1--13}, publisher = {Elsevier Ltd}, abstract = {Population receptive field (pRF) modelling is a common technique for estimating the stimulus-selectivity of populations of neurons using neuroimaging. Here, we aimed to address if pRF properties estimated with this method depend on the spatio-temporal structure and the predictability of the mapping stimulus. We mapped the polar angle preference and tuning width of voxels in visual cortex (V1–V4) of healthy, adult volunteers. We compared sequences sweeping orderly through the visual field or jumping from location to location employing stimuli of different width (45° vs 6°) and cycles of variable duration (8s vs 60s). While we did not observe any systematic influence of stimulus predictability, the temporal structure of the sequences significantly affected tuning width estimates. Ordered designs with large wedges and short cycles produced systematically smaller estimates than random sequences. Interestingly, when we used small wedges and long cycles, we obtained larger tuning width estimates for ordered than random sequences. We suggest that ordered and random mapping protocols show different susceptibility to other design choices such as stimulus type and duration of the mapping cycle and can produce significantly different pRF results.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Population receptive field (pRF) modelling is a common technique for estimating the stimulus-selectivity of populations of neurons using neuroimaging. Here, we aimed to address if pRF properties estimated with this method depend on the spatio-temporal structure and the predictability of the mapping stimulus. We mapped the polar angle preference and tuning width of voxels in visual cortex (V1–V4) of healthy, adult volunteers. We compared sequences sweeping orderly through the visual field or jumping from location to location employing stimuli of different width (45° vs 6°) and cycles of variable duration (8s vs 60s). While we did not observe any systematic influence of stimulus predictability, the temporal structure of the sequences significantly affected tuning width estimates. Ordered designs with large wedges and short cycles produced systematically smaller estimates than random sequences. Interestingly, when we used small wedges and long cycles, we obtained larger tuning width estimates for ordered than random sequences. We suggest that ordered and random mapping protocols show different susceptibility to other design choices such as stimulus type and duration of the mapping cycle and can produce significantly different pRF results. |
Monika Intaitė; João Valente Duarte; Miguel Castelo-Branco Working memory load influences perceptual ambiguity by competing for fronto-parietal attentional resources Journal Article Brain Research, 1650 , pp. 142–151, 2016. @article{Intaite2016, title = {Working memory load influences perceptual ambiguity by competing for fronto-parietal attentional resources}, author = {Monika Intaitė and Jo{ã}o Valente Duarte and Miguel Castelo-Branco}, doi = {10.1016/j.brainres.2016.08.044}, year = {2016}, date = {2016-01-01}, journal = {Brain Research}, volume = {1650}, pages = {142--151}, abstract = {A visual stimulus is defined as ambiguous when observers perceive it as having at least two distinct and spontaneously alternating interpretations. Neuroimaging studies suggest an involvement of a right fronto-parietal network regulating the balance between stable percepts and the triggering of alternative interpretations. As spontaneous perceptual reversals may occur even in the absence of attention to these stimuli, we investigated neural activity patterns in response to perceptual changes of ambiguous Necker cube under different amounts of working memory load using a dual-task design. We hypothesized that the same regions that process working memory load are involved in perceptual switching and confirmed the prediction that perceptual reversals led to fMRI responses that linearly depended on load. Accordingly, posterior Superior Parietal Lobule, anterior Prefrontal and Dorsolateral Prefrontal cortices exhibited differential BOLD signal changes in response to perceptual reversals under working memory load. Our results also suggest that the posterior Superior Parietal Lobule may be directly involved in the emergence of perceptual reversals, given that it specifically reflects both perceptual versus real changes and load levels. The anterior Prefrontal and Dorsolateral Prefrontal cortices, showing a significant interaction between reversal levels and load, might subserve a modulatory role in such reversals, in a mirror symmetric way: in the former activation is suppressed by the highest loads, and in the latter deactivation is reduced by highest loads, suggesting a more direct role of the aPFC in reversal generation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A visual stimulus is defined as ambiguous when observers perceive it as having at least two distinct and spontaneously alternating interpretations. Neuroimaging studies suggest an involvement of a right fronto-parietal network regulating the balance between stable percepts and the triggering of alternative interpretations. As spontaneous perceptual reversals may occur even in the absence of attention to these stimuli, we investigated neural activity patterns in response to perceptual changes of ambiguous Necker cube under different amounts of working memory load using a dual-task design. We hypothesized that the same regions that process working memory load are involved in perceptual switching and confirmed the prediction that perceptual reversals led to fMRI responses that linearly depended on load. Accordingly, posterior Superior Parietal Lobule, anterior Prefrontal and Dorsolateral Prefrontal cortices exhibited differential BOLD signal changes in response to perceptual reversals under working memory load. Our results also suggest that the posterior Superior Parietal Lobule may be directly involved in the emergence of perceptual reversals, given that it specifically reflects both perceptual versus real changes and load levels. The anterior Prefrontal and Dorsolateral Prefrontal cortices, showing a significant interaction between reversal levels and load, might subserve a modulatory role in such reversals, in a mirror symmetric way: in the former activation is suppressed by the highest loads, and in the latter deactivation is reduced by highest loads, suggesting a more direct role of the aPFC in reversal generation. |
Leyla Isik; Ethan M Meyers; Joel Z Leibo; Tomaso Poggio The dynamics of invariant object recognition in the human visual system Journal Article Journal of Neurophysiology, 111 (1), pp. 91–102, 2014. @article{Isik2014, title = {The dynamics of invariant object recognition in the human visual system}, author = {Leyla Isik and Ethan M Meyers and Joel Z Leibo and Tomaso Poggio}, doi = {10.1152/jn.00394.2013}, year = {2014}, date = {2014-01-01}, journal = {Journal of Neurophysiology}, volume = {111}, number = {1}, pages = {91--102}, abstract = {The human visual system can rapidly recognize objects despite transformations that alter their appearance. The precise timing of when the brain computes neural representations that are invariant to particular transformations, however, has not been mapped in humans. Here we employ magnetoencephalography decoding analysis to measure the dynamics of size- and position-invariant visual information development in the ventral visual stream. With this method we can read out the identity of objects beginning as early as 60 ms. Size- and position-invariant visual information appear around 125 ms and 150 ms, respectively, and both develop in stages, with invariance to smaller transformations arising before invariance to larger transformations. Additionally, the magnetoencephalography sensor activity localizes to neural sources that are in the most posterior occipital regions at the early decoding times and then move temporally as invariant information develops. These results provide previously unknown latencies for key stages of human-invariant object recognition, as well as new and compelling evidence for a feed-forward hierarchical model of invariant object recognition where invariance increases at each successive visual area along the ventral stream.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The human visual system can rapidly recognize objects despite transformations that alter their appearance. The precise timing of when the brain computes neural representations that are invariant to particular transformations, however, has not been mapped in humans. Here we employ magnetoencephalography decoding analysis to measure the dynamics of size- and position-invariant visual information development in the ventral visual stream. With this method we can read out the identity of objects beginning as early as 60 ms. Size- and position-invariant visual information appear around 125 ms and 150 ms, respectively, and both develop in stages, with invariance to smaller transformations arising before invariance to larger transformations. Additionally, the magnetoencephalography sensor activity localizes to neural sources that are in the most posterior occipital regions at the early decoding times and then move temporally as invariant information develops. These results provide previously unknown latencies for key stages of human-invariant object recognition, as well as new and compelling evidence for a feed-forward hierarchical model of invariant object recognition where invariance increases at each successive visual area along the ventral stream. |
Sharna D Jamadar; Beth P Johnson; Meaghan Clough; Gary F Egan; Joanne Fielding Behavioral and neural plasticity of ocular motor control: Changes in performance and fMRI activity following antisaccade training Journal Article Frontiers in Human Neuroscience, 9 (653), pp. 1–13, 2015. @article{Jamadar2015, title = {Behavioral and neural plasticity of ocular motor control: Changes in performance and fMRI activity following antisaccade training}, author = {Sharna D Jamadar and Beth P Johnson and Meaghan Clough and Gary F Egan and Joanne Fielding}, doi = {10.3389/fnhum.2015.00653}, year = {2015}, date = {2015-01-01}, journal = {Frontiers in Human Neuroscience}, volume = {9}, number = {653}, pages = {1--13}, abstract = {The antisaccade task provides a model paradigm that sets the inhibition of a reflexively driven behavior against the volitional control of a goal-directed behavior. The stability and adaptability of antisaccade performance was investigated in 23 neurologically healthy individuals. Behavior and brain function were measured using functional magnetic resonance imaging (fMRI) prior to and immediately following 2 weeks of daily antisaccade training. Participants performed antisaccade trials faster with no change in directional error rate following 2 weeks of training; however this increased speed came at the cost of the spatial accuracy of the saccade (gain) which became more hypometric following training. Training on the antisaccade task resulted in increases in fMRI activity in the fronto-basal ganglia-parietal-cerebellar ocular motor network. Following training, antisaccade latency was positively associated with fMRI activity in the frontal and supplementary eye fields, anterior cingulate and intraparietal sulcus; antisaccade gain was negatively associated with fMRI activity in supplementary eye fields, anterior cingulate, intraparietal sulcus, and cerebellar vermis. In sum, the results suggest that following training, larger antisaccade latency is associated with larger activity in fronto-parietal-cerebellar ocular motor regions, and smaller antisaccade gain is associated with larger activity in fronto-parietal ocular motor regions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The antisaccade task provides a model paradigm that sets the inhibition of a reflexively driven behavior against the volitional control of a goal-directed behavior. The stability and adaptability of antisaccade performance was investigated in 23 neurologically healthy individuals. Behavior and brain function were measured using functional magnetic resonance imaging (fMRI) prior to and immediately following 2 weeks of daily antisaccade training. Participants performed antisaccade trials faster with no change in directional error rate following 2 weeks of training; however this increased speed came at the cost of the spatial accuracy of the saccade (gain) which became more hypometric following training. Training on the antisaccade task resulted in increases in fMRI activity in the fronto-basal ganglia-parietal-cerebellar ocular motor network. Following training, antisaccade latency was positively associated with fMRI activity in the frontal and supplementary eye fields, anterior cingulate and intraparietal sulcus; antisaccade gain was negatively associated with fMRI activity in supplementary eye fields, anterior cingulate, intraparietal sulcus, and cerebellar vermis. In sum, the results suggest that following training, larger antisaccade latency is associated with larger activity in fronto-parietal-cerebellar ocular motor regions, and smaller antisaccade gain is associated with larger activity in fronto-parietal ocular motor regions. |
Yaseen A Jamal; Daniel D Dilks Rapid topographic reorganization in adult human primary visual cortex (V1) during noninvasive and reversible deprivation Journal Article Proceedings of the National Academy of Sciences, 117 (20), pp. 11059–11067, 2020. @article{Jamal2020, title = {Rapid topographic reorganization in adult human primary visual cortex (V1) during noninvasive and reversible deprivation}, author = {Yaseen A Jamal and Daniel D Dilks}, doi = {10.1073/pnas.1921860117}, year = {2020}, date = {2020-01-01}, journal = {Proceedings of the National Academy of Sciences}, volume = {117}, number = {20}, pages = {11059--11067}, abstract = {Can the primary visual cortex (V1), once wired up in development, change in adulthood? Although numerous studies have demonstrated topographic reorganization in adult V1 following the loss of bottom-up input, others have challenged such findings, offering alternative explanations. Here we use a noninvasive and reversible deprivation paradigm and converging neural and behavioral approaches to address these alternatives in the experimental test case of short-term topographic reorganization in adult human V1. Specifically, we patched one eye in typical adults, thereby depriving the cortical representation of the other eye's blind spot (BS), and immediately tested for topographic reorganization using functional magnetic resonance imaging and psychophysics. Strikingly, within just minutes of eye-patching, the BS representation in V1 began responding to stimuli presented outside of the BS, and these same stimuli were perceived as elongated toward the BS. Thus, we provide converging neural and behavioral evidence of rapid topographic reorganization in adult human V1, and the strongest evidence yet that visual deprivation produces bona fide cortical change.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Can the primary visual cortex (V1), once wired up in development, change in adulthood? Although numerous studies have demonstrated topographic reorganization in adult V1 following the loss of bottom-up input, others have challenged such findings, offering alternative explanations. Here we use a noninvasive and reversible deprivation paradigm and converging neural and behavioral approaches to address these alternatives in the experimental test case of short-term topographic reorganization in adult human V1. Specifically, we patched one eye in typical adults, thereby depriving the cortical representation of the other eye's blind spot (BS), and immediately tested for topographic reorganization using functional magnetic resonance imaging and psychophysics. Strikingly, within just minutes of eye-patching, the BS representation in V1 began responding to stimuli presented outside of the BS, and these same stimuli were perceived as elongated toward the BS. Thus, we provide converging neural and behavioral evidence of rapid topographic reorganization in adult human V1, and the strongest evidence yet that visual deprivation produces bona fide cortical change. |
Andreas Jarvstad; Iain D Gilchrist Cognitive control of saccadic selection and inhibition from within the core cortical saccadic network Journal Article Journal of Neuroscience, 39 (13), pp. 2497–2508, 2019. @article{Jarvstad2019, title = {Cognitive control of saccadic selection and inhibition from within the core cortical saccadic network}, author = {Andreas Jarvstad and Iain D Gilchrist}, doi = {10.1523/JNEUROSCI.1419-18.2018}, year = {2019}, date = {2019-01-01}, journal = {Journal of Neuroscience}, volume = {39}, number = {13}, pages = {2497--2508}, abstract = {The ability to select the task-relevant stimulus for a saccadic eye movement, while inhibiting saccades to task-irrelevant stimuli, is crucial for active vision. Here, we present a novel saccade-contingent behavioral paradigm and investigate the neural basis of the central cognitive functions underpinning such behavior, saccade selection, saccade inhibition, and saccadic choice, in female and male human participants. The paradigm allows for exceptionally well-matched contrasts, with task demands formalized with stochastic accumulation-to-threshold models. Using fMRI, we replicated the core cortical eye-movement network for saccade generation (frontal eye fields, posterior parietal cortex, and higher-level visual areas). However, in contrast to previously published tasks, saccadic selection and inhibition recruited only this core network. Brain-behavior analyses further showed that inhibition efficiency may be underpinned by white-matter integrity of tracts between key saccade-generating regions, and that inhibition efficiency is associated with right inferior frontal gyrus engagement, potentially implementing general-purpose inhibition. The core network, however, was insufficient for saccadic choice, which recruited anterior regions commonly attributed to saccadic action selection, including dorsolateral prefrontal cortex and anterior cingulate cortex. Jointly, the results indicate that extra-saccadic activity observed for free choice, and in previously published tasks probing saccadic control, is likely due to increased load on higher-level cognitive processes, and not saccadic selection per se, which is achieved within the canonical cortical eye movement network.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The ability to select the task-relevant stimulus for a saccadic eye movement, while inhibiting saccades to task-irrelevant stimuli, is crucial for active vision. Here, we present a novel saccade-contingent behavioral paradigm and investigate the neural basis of the central cognitive functions underpinning such behavior, saccade selection, saccade inhibition, and saccadic choice, in female and male human participants. The paradigm allows for exceptionally well-matched contrasts, with task demands formalized with stochastic accumulation-to-threshold models. Using fMRI, we replicated the core cortical eye-movement network for saccade generation (frontal eye fields, posterior parietal cortex, and higher-level visual areas). However, in contrast to previously published tasks, saccadic selection and inhibition recruited only this core network. Brain-behavior analyses further showed that inhibition efficiency may be underpinned by white-matter integrity of tracts between key saccade-generating regions, and that inhibition efficiency is associated with right inferior frontal gyrus engagement, potentially implementing general-purpose inhibition. The core network, however, was insufficient for saccadic choice, which recruited anterior regions commonly attributed to saccadic action selection, including dorsolateral prefrontal cortex and anterior cingulate cortex. Jointly, the results indicate that extra-saccadic activity observed for free choice, and in previously published tasks probing saccadic control, is likely due to increased load on higher-level cognitive processes, and not saccadic selection per se, which is achieved within the canonical cortical eye movement network. |
Su Keun Jeong; Yaoda Xu The impact of top-down spatial attention on laterality and hemispheric asymmetry in the human parietal cortex Journal Article Journal of Vision, 16 (10), pp. 1–21, 2016. @article{Jeong2016, title = {The impact of top-down spatial attention on laterality and hemispheric asymmetry in the human parietal cortex}, author = {Su Keun Jeong and Yaoda Xu}, doi = {10.1167/16.10.2}, year = {2016}, date = {2016-01-01}, journal = {Journal of Vision}, volume = {16}, number = {10}, pages = {1--21}, abstract = {The human parietal cortex exhibits a preference to contralaterally presented visual stimuli (i.e., laterality) as well as an asymmetry between the two hemispheres with the left parietal cortex showing greater laterality than the right. Using visual short-term memory and perceptual tasks and varying target location predictability, this study examined whether hemispheric laterality and asymmetry are fixed characteristics of the human parietal cortex or whether they are dynamic and modulated by the deployment of top-down attention to the target present hemifield. Two parietal regions were examined here that have previously been shown to be involved in visual object individuation and identification and are located in the inferior and superior intraparietal sulcus (IPS), respectively. Across three experiments, significant laterality was found in both parietal regions regardless of attentional modulation with laterality being greater in the inferior than superior IPS, consistent with their roles in object individuation and identification, respectively. Although the deployment of top-down attention had no effect on the superior IPS, it significantly increased laterality in the inferior IPS. The deployment of top-down spatial attention can thus amplify the strength of laterality in the inferior IPS. Hemispheric asymmetry, on the other hand, was absent in both brain regions and only emerged in the inferior but not the superior IPS with the deployment of top-down attention. Interestingly, the strength of hemispheric asymmetry significantly correlated with the strength of laterality in the inferior IPS. Hemispheric asymmetry thus seems to only emerge when there is a sufficient amount of laterality present in a brain region.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The human parietal cortex exhibits a preference to contralaterally presented visual stimuli (i.e., laterality) as well as an asymmetry between the two hemispheres with the left parietal cortex showing greater laterality than the right. Using visual short-term memory and perceptual tasks and varying target location predictability, this study examined whether hemispheric laterality and asymmetry are fixed characteristics of the human parietal cortex or whether they are dynamic and modulated by the deployment of top-down attention to the target present hemifield. Two parietal regions were examined here that have previously been shown to be involved in visual object individuation and identification and are located in the inferior and superior intraparietal sulcus (IPS), respectively. Across three experiments, significant laterality was found in both parietal regions regardless of attentional modulation with laterality being greater in the inferior than superior IPS, consistent with their roles in object individuation and identification, respectively. Although the deployment of top-down attention had no effect on the superior IPS, it significantly increased laterality in the inferior IPS. The deployment of top-down spatial attention can thus amplify the strength of laterality in the inferior IPS. Hemispheric asymmetry, on the other hand, was absent in both brain regions and only emerged in the inferior but not the superior IPS with the deployment of top-down attention. Interestingly, the strength of hemispheric asymmetry significantly correlated with the strength of laterality in the inferior IPS. Hemispheric asymmetry thus seems to only emerge when there is a sufficient amount of laterality present in a brain region. |
Su Keun Jeong; Yaoda Xu Task-context-dependent linear representation of multiple visual objects in human parietal cortex Journal Article Journal of Cognitive Neuroscience, 29 (10), pp. 1778–1789, 2017. @article{Jeong2017, title = {Task-context-dependent linear representation of multiple visual objects in human parietal cortex}, author = {Su Keun Jeong and Yaoda Xu}, doi = {10.1162/jocn_a_01156}, year = {2017}, date = {2017-01-01}, journal = {Journal of Cognitive Neuroscience}, volume = {29}, number = {10}, pages = {1778--1789}, abstract = {A host of recent studies have reported robust representations of visual object information in the human parietal cortex, similar to those found in ventral visual cortex. In ventral visual cortex, both monkey neurophysiology and human fMRI studies showed that the neural representation ofa pair ofunrelated objects can be approximated by the averaged neural representation of the constituent objects shown in isolation. In this study, we examined whether such a linear relationship between objects exists for object representations in the human parietal cortex. Using fMRI and multivoxel pattern analysis, we examined object representations in human inferior and superior intraparietal sulcus, two parietal regions previously implicated in visual object selection and encoding, respectively. We also examined responses from the lateral occipital region, a ventral object processing area. We obtained fMRI response patterns to object pairs and their constituent objects shown in isolation while participants viewed these objects and performed a 1-back repetition detection task. By measuring fMRI response pattern correlations, we found that all three brain regions contained representations for both single object and object pairs. In the lateral occipital region, the representation for a pair ofobjects could be reliably approximated by the average representation of its constituent objects shown in isolation, replicating previous findings in ventral visual cortex. Such a simple linear relationship, however, was not observed in either parietal region examined. Nevertheless, when we equated the amount of task information present by examining responses from two pairs of objects, we found that representations for the average of two object pairs were indistinguishable in both parietal regions from the average of another two object pairs containing the same four component objects but with a different pairing of the objects (i.e., the average of AB and CD vs. that of AD and CB). Thus, when task information was held consistent, the same linear relationship may govern how multiple independent objects are represented in the human parietal cortex as it does in ventral visual cortex. These findings show that object and task representations coexist in the human parietal cortex and characterize one significant dif- ference of how visual information may be represented in ventral visual and parietal regions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A host of recent studies have reported robust representations of visual object information in the human parietal cortex, similar to those found in ventral visual cortex. In ventral visual cortex, both monkey neurophysiology and human fMRI studies showed that the neural representation ofa pair ofunrelated objects can be approximated by the averaged neural representation of the constituent objects shown in isolation. In this study, we examined whether such a linear relationship between objects exists for object representations in the human parietal cortex. Using fMRI and multivoxel pattern analysis, we examined object representations in human inferior and superior intraparietal sulcus, two parietal regions previously implicated in visual object selection and encoding, respectively. We also examined responses from the lateral occipital region, a ventral object processing area. We obtained fMRI response patterns to object pairs and their constituent objects shown in isolation while participants viewed these objects and performed a 1-back repetition detection task. By measuring fMRI response pattern correlations, we found that all three brain regions contained representations for both single object and object pairs. In the lateral occipital region, the representation for a pair ofobjects could be reliably approximated by the average representation of its constituent objects shown in isolation, replicating previous findings in ventral visual cortex. Such a simple linear relationship, however, was not observed in either parietal region examined. Nevertheless, when we equated the amount of task information present by examining responses from two pairs of objects, we found that representations for the average of two object pairs were indistinguishable in both parietal regions from the average of another two object pairs containing the same four component objects but with a different pairing of the objects (i.e., the average of AB and CD vs. that of AD and CB). Thus, when task information was held consistent, the same linear relationship may govern how multiple independent objects are represented in the human parietal cortex as it does in ventral visual cortex. These findings show that object and task representations coexist in the human parietal cortex and characterize one significant dif- ference of how visual information may be represented in ventral visual and parietal regions. |
Trenton A Jerde; Elisha P Merriam; Adam C Riggall; James H Hedges; Clayton E Curtis Prioritized maps of space in human frontoparietal cortex Journal Article Journal of Neuroscience, 32 (48), pp. 17382–17390, 2012. @article{Jerde2012, title = {Prioritized maps of space in human frontoparietal cortex}, author = {Trenton A Jerde and Elisha P Merriam and Adam C Riggall and James H Hedges and Clayton E Curtis}, doi = {10.1523/JNEUROSCI.3810-12.2012}, year = {2012}, date = {2012-01-01}, journal = {Journal of Neuroscience}, volume = {32}, number = {48}, pages = {17382--17390}, abstract = {Priority maps are theorized to be composed of large populations of neurons organized topographically into a map of gaze-centered space whose activity spatially tags salient and behaviorally relevant information. Here, we identified four priority map candidates along human posterior intraparietal sulcus (IPS0-IPS3) and two along the precentral sulcus (PCS) that contained reliable retinotopically organized maps of contralateral visual space. Persistent activity increased from posterior-to-anterior IPS areas and from inferior-to-superior PCS areas during the maintenance of a working memory representation, the maintenance of covert attention, and the maintenance of a saccade plan. Moreover, decoders trained to predict the locations on one task (e.g., working memory) cross-predicted the locations on other tasks (e.g., attention) in superior PCS and IPS2, suggesting that these patterns of maintenance activity may be interchangeable across the tasks. Such properties make these two areas in frontal and parietal cortex viable priority map candidates.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Priority maps are theorized to be composed of large populations of neurons organized topographically into a map of gaze-centered space whose activity spatially tags salient and behaviorally relevant information. Here, we identified four priority map candidates along human posterior intraparietal sulcus (IPS0-IPS3) and two along the precentral sulcus (PCS) that contained reliable retinotopically organized maps of contralateral visual space. Persistent activity increased from posterior-to-anterior IPS areas and from inferior-to-superior PCS areas during the maintenance of a working memory representation, the maintenance of covert attention, and the maintenance of a saccade plan. Moreover, decoders trained to predict the locations on one task (e.g., working memory) cross-predicted the locations on other tasks (e.g., attention) in superior PCS and IPS2, suggesting that these patterns of maintenance activity may be interchangeable across the tasks. Such properties make these two areas in frontal and parietal cortex viable priority map candidates. |
Michael Jigo; Mengyuan Gong; Taosheng Liu Neural determinants of task performance during feature-based attention in human cortex Journal Article Eneuro, 5 (1), pp. 1–15, 2018. @article{Jigo2018b, title = {Neural determinants of task performance during feature-based attention in human cortex}, author = {Michael Jigo and Mengyuan Gong and Taosheng Liu}, doi = {10.1523/eneuro.0375-17.2018}, year = {2018}, date = {2018-01-01}, journal = {Eneuro}, volume = {5}, number = {1}, pages = {1--15}, abstract = {Studies of feature-based attention have associated activity in a dorsal frontoparietal network with putative attentional priority signals. Yet, how this neural activity mediates attentional selection and whether it guides behavior are fundamental questions that require investigation. We reasoned that endogenous fluctuations in the quality of attentional priority should influence task performance. Human subjects detected a speed increment while viewing clockwise (CW) or counterclockwise (CCW) motion (baseline task) or while attending to either direction amid distracters (attention task). In an fMRI experiment, direction-specific neural pattern similarity between the baseline task and the attention task revealed a higher level of similarity for correct than incorrect trials in frontoparietal regions. Using transcranial magnetic stimulation (TMS), we disrupted posterior parietal cortex (PPC) and found a selective deficit in the attention task, but not in the baseline task, demonstrating the necessity of this cortical area during feature-based attention. These results reveal that frontoparietal areas maintain attentional priority that facilitates successful behavioral selection.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Studies of feature-based attention have associated activity in a dorsal frontoparietal network with putative attentional priority signals. Yet, how this neural activity mediates attentional selection and whether it guides behavior are fundamental questions that require investigation. We reasoned that endogenous fluctuations in the quality of attentional priority should influence task performance. Human subjects detected a speed increment while viewing clockwise (CW) or counterclockwise (CCW) motion (baseline task) or while attending to either direction amid distracters (attention task). In an fMRI experiment, direction-specific neural pattern similarity between the baseline task and the attention task revealed a higher level of similarity for correct than incorrect trials in frontoparietal regions. Using transcranial magnetic stimulation (TMS), we disrupted posterior parietal cortex (PPC) and found a selective deficit in the attention task, but not in the baseline task, demonstrating the necessity of this cortical area during feature-based attention. These results reveal that frontoparietal areas maintain attentional priority that facilitates successful behavioral selection. |
Zoran Josipovic; Ilan Dinstein; Jochen Weber; David J Heeger Influence of meditation on anti-correlated networks in the brain Journal Article Frontiers in Human Neuroscience, 5 , pp. 1–11, 2012. @article{Josipovic2012, title = {Influence of meditation on anti-correlated networks in the brain}, author = {Zoran Josipovic and Ilan Dinstein and Jochen Weber and David J Heeger}, doi = {10.3389/fnhum.2011.00183}, year = {2012}, date = {2012-01-01}, journal = {Frontiers in Human Neuroscience}, volume = {5}, pages = {1--11}, abstract = {Human experiences can be broadly divided into those that are external and related to interaction with the environment, and experiences that are internal and self-related. The cerebral cortex appears to be divided into two corresponding systems: an "extrinsic" system composed of brain areas that respond more to external stimuli and tasks and an "intrinsic" system composed of brain areas that respond less to external stimuli and tasks. These two broad brain systems seem to compete with each other, such that their activity levels over time is usually anti-correlated, even when subjects are "at rest" and not performing any task. This study used meditation as an experimental manipulation to test whether this competition (anti-correlation) can be modulated by cognitive strategy. Participants either fixated without meditation (fixation), or engaged in non-dual awareness (NDA) or focused attention (FA) meditations. We computed inter-area correlations ("functional connectivity") between pairs of brain regions within each system, and between the entire extrinsic and intrinsic systems. Anti-correlation between extrinsic vs. intrinsic systems was stronger during FA meditation and weaker during NDA meditation in comparison to fixation (without mediation). However, correlation between areas within each system did not change across conditions. These results suggest that the anti-correlation found between extrinsic and intrinsic systems is not an immutable property of brain organization and that practicing different forms of meditation can modulate this gross functional organization in profoundly different ways.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Human experiences can be broadly divided into those that are external and related to interaction with the environment, and experiences that are internal and self-related. The cerebral cortex appears to be divided into two corresponding systems: an "extrinsic" system composed of brain areas that respond more to external stimuli and tasks and an "intrinsic" system composed of brain areas that respond less to external stimuli and tasks. These two broad brain systems seem to compete with each other, such that their activity levels over time is usually anti-correlated, even when subjects are "at rest" and not performing any task. This study used meditation as an experimental manipulation to test whether this competition (anti-correlation) can be modulated by cognitive strategy. Participants either fixated without meditation (fixation), or engaged in non-dual awareness (NDA) or focused attention (FA) meditations. We computed inter-area correlations ("functional connectivity") between pairs of brain regions within each system, and between the entire extrinsic and intrinsic systems. Anti-correlation between extrinsic vs. intrinsic systems was stronger during FA meditation and weaker during NDA meditation in comparison to fixation (without mediation). However, correlation between areas within each system did not change across conditions. These results suggest that the anti-correlation found between extrinsic and intrinsic systems is not an immutable property of brain organization and that practicing different forms of meditation can modulate this gross functional organization in profoundly different ways. |
Anna-Maria Kasparbauer; Inga Meyhöfer; Maria Steffens; Bernd Weber; Merve Aydin; Veena Kumari; Rene HWIBBLEemann; Ulrich Ettinger Neural effects of methylphenidate and nicotine during smooth pursuit eye movements Journal Article NeuroImage, 141 , pp. 52–59, 2016. @article{Kasparbauer2016, title = {Neural effects of methylphenidate and nicotine during smooth pursuit eye movements}, author = {Anna-Maria Kasparbauer and Inga Meyhöfer and Maria Steffens and Bernd Weber and Merve Aydin and Veena Kumari and Rene HWIBBLEemann and Ulrich Ettinger}, doi = {10.1016/j.neuroimage.2016.07.012}, year = {2016}, date = {2016-01-01}, journal = {NeuroImage}, volume = {141}, pages = {52--59}, publisher = {Elsevier Inc.}, abstract = {Introduction: Nicotine and methylphenidate are putative cognitive enhancers in healthy and patient populations. Although they stimulate different neurotransmitter systems, they have been shown to enhance performance on overlapping measures of attention. So far, there has been no direct comparison of the effects of these two stimulants on behavioural performance or brain function in healthy humans. Here, we directly compare the two compounds using a well-established oculomotor biomarker in order to explore common and distinct behavioural and neural effects. Methods: Eighty-two healthy male non-smokers performed a smooth pursuit eye movement task while lying in an fMRI scanner. In a between-subjects, double-blind design, subjects either received placebo (placebo patch and capsule), nicotine (7 mg nicotine patch and placebo capsule), or methylphenidate (placebo patch and 40 mg methylphenidate capsule). Results: There were no significant drug effects on behavioural measures. At the neural level, methylphenidate elicited higher activation in left frontal eye field compared to nicotine, with an intermediate response under placebo. Discussion: The reduced activation of task-related regions under nicotine could be associated with more efficient neural processing, while increased hemodynamic response under methylphenidate is interpretable as enhanced processing of task-relevant networks. Together, these findings suggest dissociable neural effects of these putative cognitive enhancers.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Introduction: Nicotine and methylphenidate are putative cognitive enhancers in healthy and patient populations. Although they stimulate different neurotransmitter systems, they have been shown to enhance performance on overlapping measures of attention. So far, there has been no direct comparison of the effects of these two stimulants on behavioural performance or brain function in healthy humans. Here, we directly compare the two compounds using a well-established oculomotor biomarker in order to explore common and distinct behavioural and neural effects. Methods: Eighty-two healthy male non-smokers performed a smooth pursuit eye movement task while lying in an fMRI scanner. In a between-subjects, double-blind design, subjects either received placebo (placebo patch and capsule), nicotine (7 mg nicotine patch and placebo capsule), or methylphenidate (placebo patch and 40 mg methylphenidate capsule). Results: There were no significant drug effects on behavioural measures. At the neural level, methylphenidate elicited higher activation in left frontal eye field compared to nicotine, with an intermediate response under placebo. Discussion: The reduced activation of task-related regions under nicotine could be associated with more efficient neural processing, while increased hemodynamic response under methylphenidate is interpretable as enhanced processing of task-relevant networks. Together, these findings suggest dissociable neural effects of these putative cognitive enhancers. |
Jukka Pekka Kauppi; Melih Kandemir; Veli Matti Saarinen; Lotta Hirvenkari; Lauri Parkkonen; Arto Klami; Riitta Hari; Samuel Kaski Towards brain-activity-controlled information retrieval: Decoding image relevance from MEG signals Journal Article NeuroImage, 112 , pp. 288–298, 2015. @article{Kauppi2015, title = {Towards brain-activity-controlled information retrieval: Decoding image relevance from MEG signals}, author = {Jukka Pekka Kauppi and Melih Kandemir and Veli Matti Saarinen and Lotta Hirvenkari and Lauri Parkkonen and Arto Klami and Riitta Hari and Samuel Kaski}, doi = {10.1016/j.neuroimage.2014.12.079}, year = {2015}, date = {2015-01-01}, journal = {NeuroImage}, volume = {112}, pages = {288--298}, publisher = {Elsevier Inc.}, abstract = {We hypothesize that brain activity can be used to control future information retrieval systems. To this end, we conducted a feasibility study on predicting the relevance of visual objects from brain activity. We analyze both magnetoencephalographic (MEG) and gaze signals from nine subjects who were viewing image collages, a subset of which was relevant to a predetermined task. We report three findings: i) the relevance of an image a subject looks at can be decoded from MEG signals with performance significantly better than chance, ii) fusion of gaze-based and MEG-based classifiers significantly improves the prediction performance compared to using either signal alone, and iii) non-linear classification of the MEG signals using Gaussian process classifiers outperforms linear classification. These findings break new ground for building brain-activity-based interactive image retrieval systems, as well as for systems utilizing feedback both from brain activity and eye movements.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We hypothesize that brain activity can be used to control future information retrieval systems. To this end, we conducted a feasibility study on predicting the relevance of visual objects from brain activity. We analyze both magnetoencephalographic (MEG) and gaze signals from nine subjects who were viewing image collages, a subset of which was relevant to a predetermined task. We report three findings: i) the relevance of an image a subject looks at can be decoded from MEG signals with performance significantly better than chance, ii) fusion of gaze-based and MEG-based classifiers significantly improves the prediction performance compared to using either signal alone, and iii) non-linear classification of the MEG signals using Gaussian process classifiers outperforms linear classification. These findings break new ground for building brain-activity-based interactive image retrieval systems, as well as for systems utilizing feedback both from brain activity and eye movements. |
Janne Kauttonen; Yevhen Hlushchuk; Iiro P Jääskeläinen; Pia Tikka Brain mechanisms underlying cue-based memorizing during free viewing of movie Memento Journal Article NeuroImage, 172 , pp. 313–325, 2018. @article{Kauttonen2018, title = {Brain mechanisms underlying cue-based memorizing during free viewing of movie Memento}, author = {Janne Kauttonen and Yevhen Hlushchuk and Iiro P Jääskeläinen and Pia Tikka}, doi = {10.1016/j.neuroimage.2018.01.068}, year = {2018}, date = {2018-01-01}, journal = {NeuroImage}, volume = {172}, pages = {313--325}, abstract = {How does the human brain recall and connect relevant memories with unfolding events? To study this, we presented 25 healthy subjects, during functional magnetic resonance imaging, the movie ‘Memento' (director C. Nolan). In this movie, scenes are presented in chronologically reverse order with certain scenes briefly overlapping previously presented scenes. Such overlapping “key-frames” serve as effective memory cues for the viewers, prompting recall of relevant memories of the previously seen scene and connecting them with the concurrent scene. We hypothesized that these repeating key-frames serve as immediate recall cues and would facilitate reconstruction of the story piece-by-piece. The chronological version of Memento, shown in a separate experiment for another group of subjects, served as a control condition. Using multivariate event-related pattern analysis method and representational similarity analysis, focal fingerprint patterns of hemodynamic activity were found to emerge during presentation of key-frame scenes. This effect was present in higher-order cortical network with regions including precuneus, angular gyrus, cingulate gyrus, as well as lateral, superior, and middle frontal gyri within frontal poles. This network was right hemispheric dominant. These distributed patterns of brain activity appear to underlie ability to recall relevant memories and connect them with ongoing events, i.e., “what goes with what” in a complex story. Given the real-life likeness of cinematic experience, these results provide new insight into how the human brain recalls, given proper cues, relevant memories to facilitate understanding and prediction of everyday life events.}, keywords = {}, pubstate = {published}, tppubtype = {article} } How does the human brain recall and connect relevant memories with unfolding events? To study this, we presented 25 healthy subjects, during functional magnetic resonance imaging, the movie ‘Memento' (director C. Nolan). In this movie, scenes are presented in chronologically reverse order with certain scenes briefly overlapping previously presented scenes. Such overlapping “key-frames” serve as effective memory cues for the viewers, prompting recall of relevant memories of the previously seen scene and connecting them with the concurrent scene. We hypothesized that these repeating key-frames serve as immediate recall cues and would facilitate reconstruction of the story piece-by-piece. The chronological version of Memento, shown in a separate experiment for another group of subjects, served as a control condition. Using multivariate event-related pattern analysis method and representational similarity analysis, focal fingerprint patterns of hemodynamic activity were found to emerge during presentation of key-frame scenes. This effect was present in higher-order cortical network with regions including precuneus, angular gyrus, cingulate gyrus, as well as lateral, superior, and middle frontal gyri within frontal poles. This network was right hemispheric dominant. These distributed patterns of brain activity appear to underlie ability to recall relevant memories and connect them with ongoing events, i.e., “what goes with what” in a complex story. Given the real-life likeness of cinematic experience, these results provide new insight into how the human brain recalls, given proper cues, relevant memories to facilitate understanding and prediction of everyday life events. |
Carina Kelbsch; Archana Jalligampala; Torsten Strasser; Paul Richter; Katarina Stingl; Christoph Braun; Daniel L Rathbun; Eberhart Zrenner; Helmut Wilhelm; Barbara Wilhelm; Tobias Peters; Krunoslav Stingl Phosphene perception and pupillary responses to sinusoidal electrostimulation - For an objective measurement of retinal function Journal Article Experimental Eye Research, 176 , pp. 210–218, 2018. @article{Kelbsch2018, title = {Phosphene perception and pupillary responses to sinusoidal electrostimulation - For an objective measurement of retinal function}, author = {Carina Kelbsch and Archana Jalligampala and Torsten Strasser and Paul Richter and Katarina Stingl and Christoph Braun and Daniel L Rathbun and Eberhart Zrenner and Helmut Wilhelm and Barbara Wilhelm and Tobias Peters and Krunoslav Stingl}, doi = {10.1016/j.exer.2018.07.010}, year = {2018}, date = {2018-01-01}, journal = {Experimental Eye Research}, volume = {176}, pages = {210--218}, publisher = {Elsevier}, abstract = {The purpose was to evaluate retinal function by measuring pupillary responses to sinusoidal transcorneal electrostimulation in healthy young human subjects. This work also translates data from analogous in vitro experiments and connects it to the pupillary responses obtained in human experiments. 14 healthy human subjects participated (4 males, 10 females); for the in vitro experiments, two male healthy mouse retinas (adult wild-type C57B/6J) were used. Pupillary responses to sinusoidal transcorneal electrostimulation of varying stimulus carrier frequencies (10, 20 Hz; envelope frequency constantly kept at 1.2 Hz) and intensities (10, 20, 50 $mu$A) were recorded and compared with those obtained with light stimulation (1.2 Hz sinusoidal blue, red light). A strong correlation between the sinusoidal stimulation (electrical as well as light) and the pupillary sinusoidal response was found. The difference between the lag of electrical and light stimulation allowed the estimation of an intensity threshold for pupillary responses to transcorneal electrostimulation (mean ± SD: 30 ± 10 $mu$A (10 Hz); 38 ± 10 $mu$A (20 Hz)). A comparison between the results of the two stimulation frequencies showed a not statistically significant smaller lag for 10 Hz (10 Hz: 633 ± 90 ms; 20 Hz: 725 ± 178 ms; 50 $mu$A intensity). Analogous in vitro experiments on murine retinas indicated a selective stimulation of photoreceptors and bipolar cells (lower frequencies) and retinal ganglion cells (higher frequencies) and lower stimulation thresholds for the retinal network with sinusoidal compared to pulsatile stimulation – emphasizing that sinu- soidal waveforms are well-suited to our purposes. We demonstrate that pupillary responses to sinusoidal transcorneal electrostimulation are measurable as an objective marker in healthy young subjects, even at very low stimulus intensities. By using this unique approach, we unveil the potential for an estimation of the in- dividual intensity threshold and a selective activation of different retinal cell types in humans by varying the stimulation frequency. This technique may have broad clinical utility as well as specific relevance in the monitoring of patients with hereditary retinal disorders, especially as implemented in study protocols for novel therapies, e.g. retinal prostheses or gene therapies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The purpose was to evaluate retinal function by measuring pupillary responses to sinusoidal transcorneal electrostimulation in healthy young human subjects. This work also translates data from analogous in vitro experiments and connects it to the pupillary responses obtained in human experiments. 14 healthy human subjects participated (4 males, 10 females); for the in vitro experiments, two male healthy mouse retinas (adult wild-type C57B/6J) were used. Pupillary responses to sinusoidal transcorneal electrostimulation of varying stimulus carrier frequencies (10, 20 Hz; envelope frequency constantly kept at 1.2 Hz) and intensities (10, 20, 50 $mu$A) were recorded and compared with those obtained with light stimulation (1.2 Hz sinusoidal blue, red light). A strong correlation between the sinusoidal stimulation (electrical as well as light) and the pupillary sinusoidal response was found. The difference between the lag of electrical and light stimulation allowed the estimation of an intensity threshold for pupillary responses to transcorneal electrostimulation (mean ± SD: 30 ± 10 $mu$A (10 Hz); 38 ± 10 $mu$A (20 Hz)). A comparison between the results of the two stimulation frequencies showed a not statistically significant smaller lag for 10 Hz (10 Hz: 633 ± 90 ms; 20 Hz: 725 ± 178 ms; 50 $mu$A intensity). Analogous in vitro experiments on murine retinas indicated a selective stimulation of photoreceptors and bipolar cells (lower frequencies) and retinal ganglion cells (higher frequencies) and lower stimulation thresholds for the retinal network with sinusoidal compared to pulsatile stimulation – emphasizing that sinu- soidal waveforms are well-suited to our purposes. We demonstrate that pupillary responses to sinusoidal transcorneal electrostimulation are measurable as an objective marker in healthy young subjects, even at very low stimulus intensities. By using this unique approach, we unveil the potential for an estimation of the in- dividual intensity threshold and a selective activation of different retinal cell types in humans by varying the stimulation frequency. This technique may have broad clinical utility as well as specific relevance in the monitoring of patients with hereditary retinal disorders, especially as implemented in study protocols for novel therapies, e.g. retinal prostheses or gene therapies. |
Derek Kellar; Sharlene Newman; Franco Pestilli; Hu Cheng; Nicholas L Port Comparing fMRI activation during smooth pursuit eye movements among contact sport athletes, non-contact sport athletes, and non-athletes Journal Article NeuroImage: Clinical, 18 , pp. 413–424, 2018. @article{Kellar2018, title = {Comparing fMRI activation during smooth pursuit eye movements among contact sport athletes, non-contact sport athletes, and non-athletes}, author = {Derek Kellar and Sharlene Newman and Franco Pestilli and Hu Cheng and Nicholas L Port}, doi = {10.1016/j.nicl.2018.01.025}, year = {2018}, date = {2018-01-01}, journal = {NeuroImage: Clinical}, volume = {18}, pages = {413--424}, publisher = {Elsevier}, abstract = {Objectives: Though sub-concussive impacts are common during contact sports, there is little consensus whether repeat blows affect brain function. Using a “lifetime exposure” rather than acute exposure approach, we examined oculomotor performance and brain activation among collegiate football players and two control groups. Our analysis examined whether there are group differences in eye movement behavioral performance and in brain activation during smooth pursuit. Methods: Data from 21 off-season Division I football “starters” were compared with a) 19 collegiate cross-country runners, and b) 11 non-athlete college students who were SES matched to the football player group (total N = 51). Visual smooth pursuit was performed while undergoing fMRI imaging via a 3 Tesla scanner. Smooth pursuit eye movements to three stimulus difficulty levels were measured with regard to RMS error, gain, and lag. Results: No meaningful differences were found for any of the standard analyses used to assess smooth pursuit eye movements. For fMRI, greater activation was seen in the oculomotor region of the cerebellar vermis and areas of the FEF for football players as compared to either control group, who did not differ on any measure. Conclusion: Greater cerebellar activity among football players while performing an oculomotor task could indicate that they are working harder to compensate for some subtle, long-term subconcussive deficits. Alternatively, top athletes in a sport requiring high visual motor skill could have more of their cerebellum and FEF devoted to oculomotor task performance regardless of subconcussive history. Overall, these results provide little firm support for an effect of accumulated subconcussion exposure on brain function.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Objectives: Though sub-concussive impacts are common during contact sports, there is little consensus whether repeat blows affect brain function. Using a “lifetime exposure” rather than acute exposure approach, we examined oculomotor performance and brain activation among collegiate football players and two control groups. Our analysis examined whether there are group differences in eye movement behavioral performance and in brain activation during smooth pursuit. Methods: Data from 21 off-season Division I football “starters” were compared with a) 19 collegiate cross-country runners, and b) 11 non-athlete college students who were SES matched to the football player group (total N = 51). Visual smooth pursuit was performed while undergoing fMRI imaging via a 3 Tesla scanner. Smooth pursuit eye movements to three stimulus difficulty levels were measured with regard to RMS error, gain, and lag. Results: No meaningful differences were found for any of the standard analyses used to assess smooth pursuit eye movements. For fMRI, greater activation was seen in the oculomotor region of the cerebellar vermis and areas of the FEF for football players as compared to either control group, who did not differ on any measure. Conclusion: Greater cerebellar activity among football players while performing an oculomotor task could indicate that they are working harder to compensate for some subtle, long-term subconcussive deficits. Alternatively, top athletes in a sport requiring high visual motor skill could have more of their cerebellum and FEF devoted to oculomotor task performance regardless of subconcussive history. Overall, these results provide little firm support for an effect of accumulated subconcussion exposure on brain function. |
Andy Jeesu Kim; Brian A Anderson Arousal-biased competition explains reduced distraction by reward cues under threat Journal Article eNeuro, 7 (4), pp. 1–12, 2020. @article{Kim2020, title = {Arousal-biased competition explains reduced distraction by reward cues under threat}, author = {Andy Jeesu Kim and Brian A Anderson}, doi = {10.1523/ENEURO.0099-20.2020}, year = {2020}, date = {2020-01-01}, journal = {eNeuro}, volume = {7}, number = {4}, pages = {1--12}, abstract = {Anxiety is an adaptive neural state that promotes rapid responses under heightened vigilance when survival is threatened. Anxiety has consistently been found to potentiate the attentional processing of physically salient stimuli. However, a recent study demonstrated that a threat manipulation reduces attentional capture by reward-associated stimuli, suggesting a more complex relationship between anxiety and the control of attention. The mechanisms by which threat can reduce the distracting quality of stimuli are unknown. In this study, using functional magnetic resonance imaging (fMRI) on human subjects, we examined the neural correlates of attention to previously reward-associated stimuli with and without the threat of unpredictable electric shock. We replicate enhanced distractor-evoked activity throughout the value-driven attention network (VDAN) in addition to enhanced stimulus-evoked activity generally under threat. Importantly, these two factors interacted such that the representation of previously reward-associated distractors was particularly pronounced under threat. Our results from neuroimaging fit well with the principle of arousal-biased competition (ABC), although such effects are typically associated with behavioral measures of increased attention to stimuli that already possess elevated attentional priority. The findings of our study suggest that ABC can be leveraged to support more efficient ignoring of reward cues, revealing new insights into the functional significance of ABC as a mechanism of attentional control, and provide a mechanistic explanation of how threat reduces attention to irrelevant reward information.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Anxiety is an adaptive neural state that promotes rapid responses under heightened vigilance when survival is threatened. Anxiety has consistently been found to potentiate the attentional processing of physically salient stimuli. However, a recent study demonstrated that a threat manipulation reduces attentional capture by reward-associated stimuli, suggesting a more complex relationship between anxiety and the control of attention. The mechanisms by which threat can reduce the distracting quality of stimuli are unknown. In this study, using functional magnetic resonance imaging (fMRI) on human subjects, we examined the neural correlates of attention to previously reward-associated stimuli with and without the threat of unpredictable electric shock. We replicate enhanced distractor-evoked activity throughout the value-driven attention network (VDAN) in addition to enhanced stimulus-evoked activity generally under threat. Importantly, these two factors interacted such that the representation of previously reward-associated distractors was particularly pronounced under threat. Our results from neuroimaging fit well with the principle of arousal-biased competition (ABC), although such effects are typically associated with behavioral measures of increased attention to stimuli that already possess elevated attentional priority. The findings of our study suggest that ABC can be leveraged to support more efficient ignoring of reward cues, revealing new insights into the functional significance of ABC as a mechanism of attentional control, and provide a mechanistic explanation of how threat reduces attention to irrelevant reward information. |
Andy Jeesu Kim; Brian A Anderson Neural correlates of attentional capture by stimuli previously associated with social reward Journal Article Cognitive Neuroscience, 11 (1-2), pp. 5–15, 2020. @article{Kim2020a, title = {Neural correlates of attentional capture by stimuli previously associated with social reward}, author = {Andy Jeesu Kim and Brian A Anderson}, doi = {10.1080/17588928.2019.1585338}, year = {2020}, date = {2020-01-01}, journal = {Cognitive Neuroscience}, volume = {11}, number = {1-2}, pages = {5--15}, publisher = {Routledge}, abstract = {Our attention is strongly influenced by reward learning. Stimuli previously associated with monetary reward have been shown to automatically capture attention in both behavioral and neurophysiological studies. Stimuli previously associated with positive social feedback similarly capture attention; however, it is unknown whether such social facilitation of attention relies on similar or dissociable neural systems. Here, we used the value-driven attentional capture paradigm in an fMRI study to identify the neural correlates of attention to stimuli previously associated with social reward. The results reveal learning-dependent priority signals in the contralateral visual cortex, posterior parietal cortex, and caudate tail, similar to studies using monetary reward. An additional priority signal was consistently evident in the right middle frontal gyrus (MFG). Our findings support the notion of a common neural mechanism for directing attention on the basis of selection history that generalizes across different types of reward.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Our attention is strongly influenced by reward learning. Stimuli previously associated with monetary reward have been shown to automatically capture attention in both behavioral and neurophysiological studies. Stimuli previously associated with positive social feedback similarly capture attention; however, it is unknown whether such social facilitation of attention relies on similar or dissociable neural systems. Here, we used the value-driven attentional capture paradigm in an fMRI study to identify the neural correlates of attention to stimuli previously associated with social reward. The results reveal learning-dependent priority signals in the contralateral visual cortex, posterior parietal cortex, and caudate tail, similar to studies using monetary reward. An additional priority signal was consistently evident in the right middle frontal gyrus (MFG). Our findings support the notion of a common neural mechanism for directing attention on the basis of selection history that generalizes across different types of reward. |
Rozemarijn S van Kleef; Claudi L H Bockting; Evelien van Valen; André Aleman; Jan Bernard C Marsman; Marie José van Tol BMC Psychiatry, 19 , pp. 1–11, 2019. @article{Kleef2019, title = {Neurocognitive working mechanisms of the prevention of relapse in remitted recurrent depression (NEWPRIDE): Protocol of a randomized controlled neuroimaging trial of preventive cognitive therapy}, author = {Rozemarijn S van Kleef and Claudi L H Bockting and Evelien van Valen and André Aleman and Jan Bernard C Marsman and Marie José van Tol}, doi = {10.1186/s12888-019-2384-0}, year = {2019}, date = {2019-01-01}, journal = {BMC Psychiatry}, volume = {19}, pages = {1--11}, publisher = {BMC Psychiatry}, abstract = {Background: Major Depressive Disorder (MDD) is a psychiatric disorder with a highly recurrent character, making prevention of relapse an important clinical goal. Preventive Cognitive Therapy (PCT) has been proven effective in preventing relapse, though not for every patient. A better understanding of relapse vulnerability and working mechanisms of preventive treatment may inform effective personalized intervention strategies. Neurocognitive models of MDD suggest that abnormalities in prefrontal control over limbic emotion-processing areas during emotional processing and regulation are important in understanding relapse vulnerability. Whether changes in these neurocognitive abnormalities are induced by PCT and thus play an important role in mediating the risk for recurrent depression, is currently unclear. In the Neurocognitive Working Mechanisms of the Prevention of Relapse In Depression (NEWPRIDE) study, we aim to 1) study neurocognitive factors underpinning the vulnerability for relapse, 2) understand the neurocognitive working mechanisms of PCT, 3) predict longitudinal treatment effects based on pre-treatment neurocognitive characteristics, and 4) validate the pupil dilation response as a marker for prefrontal activity, reflecting emotion regulation capacity and therapy success. Methods: In this randomized controlled trial, 75 remitted recurrent MDD (rrMDD) patients will be included. Detailed clinical and cognitive measurements, fMRI scanning and pupillometry will be performed at baseline and three-month follow-up. In the interval, 50 rrMDD patients will be randomized to eight sessions of PCT and 25 rrMDD patients to a waiting list. At baseline, 25 healthy control participants will be additionally included to objectify cross-sectional residual neurocognitive abnormalities in rrMDD. After 18 months, clinical assessments of relapse status are performed to investigate which therapy induced changes predict relapse in the 50 patients allocated to PCT. Discussion: The present trial is the first to study the neurocognitive vulnerability factors underlying relapse and mediating relapse prevention, their value for predicting PCT success and whether pupil dilation acts as a valuable marker in this regard. Ultimately, a deeper understanding of relapse prevention could contribute to the development of better targeted preventive interventions. Trial registration: Trial registration: Netherlands Trial Register, August 18, 2015, trial number NL5219.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: Major Depressive Disorder (MDD) is a psychiatric disorder with a highly recurrent character, making prevention of relapse an important clinical goal. Preventive Cognitive Therapy (PCT) has been proven effective in preventing relapse, though not for every patient. A better understanding of relapse vulnerability and working mechanisms of preventive treatment may inform effective personalized intervention strategies. Neurocognitive models of MDD suggest that abnormalities in prefrontal control over limbic emotion-processing areas during emotional processing and regulation are important in understanding relapse vulnerability. Whether changes in these neurocognitive abnormalities are induced by PCT and thus play an important role in mediating the risk for recurrent depression, is currently unclear. In the Neurocognitive Working Mechanisms of the Prevention of Relapse In Depression (NEWPRIDE) study, we aim to 1) study neurocognitive factors underpinning the vulnerability for relapse, 2) understand the neurocognitive working mechanisms of PCT, 3) predict longitudinal treatment effects based on pre-treatment neurocognitive characteristics, and 4) validate the pupil dilation response as a marker for prefrontal activity, reflecting emotion regulation capacity and therapy success. Methods: In this randomized controlled trial, 75 remitted recurrent MDD (rrMDD) patients will be included. Detailed clinical and cognitive measurements, fMRI scanning and pupillometry will be performed at baseline and three-month follow-up. In the interval, 50 rrMDD patients will be randomized to eight sessions of PCT and 25 rrMDD patients to a waiting list. At baseline, 25 healthy control participants will be additionally included to objectify cross-sectional residual neurocognitive abnormalities in rrMDD. After 18 months, clinical assessments of relapse status are performed to investigate which therapy induced changes predict relapse in the 50 patients allocated to PCT. Discussion: The present trial is the first to study the neurocognitive vulnerability factors underlying relapse and mediating relapse prevention, their value for predicting PCT success and whether pupil dilation acts as a valuable marker in this regard. Ultimately, a deeper understanding of relapse prevention could contribute to the development of better targeted preventive interventions. Trial registration: Trial registration: Netherlands Trial Register, August 18, 2015, trial number NL5219. |
Niels A Kloosterman; Thomas Meindertsma; Arjan Hillebrand; Bob W van Dijk; Victor A F Lamme; Tobias H Donner Top-down modulation in human visual cortex predicts the stability of a perceptual illusion Journal Article Journal of Neurophysiology, 113 (4), pp. 1063–1076, 2015. @article{Kloosterman2015, title = {Top-down modulation in human visual cortex predicts the stability of a perceptual illusion}, author = {Niels A Kloosterman and Thomas Meindertsma and Arjan Hillebrand and Bob W van Dijk and Victor A F Lamme and Tobias H Donner}, doi = {10.1152/jn.00338.2014}, year = {2015}, date = {2015-01-01}, journal = {Journal of Neurophysiology}, volume = {113}, number = {4}, pages = {1063--1076}, abstract = {Conscious perception sometimes fluctuates strongly, even when the sensory input is constant. For example, in motion-induced blindness (MIB), a salient visual target surrounded by a moving pattern suddenly disappears from perception, only to reappear after some variable time. Whereas such changes of perception result from fluctuations of neural activity, mounting evidence suggests that the perceptual changes, in turn, may also cause modulations of activity in several brain areas, including visual cortex. In this study, we asked whether these latter modulations might affect the subsequent dynamics of perception. We used magnetoencephalography (MEG) to measure modulations in cortical population activity during MIB. We observed a transient, retinotopically widespread modulation of beta (12-30 Hz)-frequency power over visual cortex that was closely linked to the time of subjects' behavioral report of the target disappearance. This beta modulation was a top-down signal, decoupled from both the physical stimulus properties and the motor response but contingent on the behavioral relevance of the perceptual change. Critically, the modulation amplitude predicted the duration of the subsequent target disappearance. We propose that the transformation of the perceptual change into a report triggers a top-down mechanism that stabilizes the newly selected perceptual interpretation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Conscious perception sometimes fluctuates strongly, even when the sensory input is constant. For example, in motion-induced blindness (MIB), a salient visual target surrounded by a moving pattern suddenly disappears from perception, only to reappear after some variable time. Whereas such changes of perception result from fluctuations of neural activity, mounting evidence suggests that the perceptual changes, in turn, may also cause modulations of activity in several brain areas, including visual cortex. In this study, we asked whether these latter modulations might affect the subsequent dynamics of perception. We used magnetoencephalography (MEG) to measure modulations in cortical population activity during MIB. We observed a transient, retinotopically widespread modulation of beta (12-30 Hz)-frequency power over visual cortex that was closely linked to the time of subjects' behavioral report of the target disappearance. This beta modulation was a top-down signal, decoupled from both the physical stimulus properties and the motor response but contingent on the behavioral relevance of the perceptual change. Critically, the modulation amplitude predicted the duration of the subsequent target disappearance. We propose that the transformation of the perceptual change into a report triggers a top-down mechanism that stabilizes the newly selected perceptual interpretation. |
Christian Kluge; Markus Bauer; Alexander P Leff; Hans-Jochen Heinze; Raymond J Dolan; Jon Driver; Alexander Paul Plasticity of human auditory-evoked fields induced by shock conditioning and contingency reversal Journal Article Proceedings of the National Academy of Sciences, 108 (30), pp. 12545–12550, 2011. @article{Kluge2011, title = {Plasticity of human auditory-evoked fields induced by shock conditioning and contingency reversal}, author = {Christian Kluge and Markus Bauer and Alexander P Leff and Hans-Jochen Heinze and Raymond J Dolan and Jon Driver and Alexander Paul}, doi = {10.1073/pnas.1016124108}, year = {2011}, date = {2011-01-01}, journal = {Proceedings of the National Academy of Sciences}, volume = {108}, number = {30}, pages = {12545--12550}, abstract = {We used magnetoencephalography (MEG) to assess plasticity of human auditory cortex induced by classical conditioning and contingency reversal. Participants listened to random sequences of high or low tones. A first baseline phase presented these without further associations. In phase 2, one of the frequencies (CS(+)) was paired with shock on half its occurrences, whereas the other frequency (CS(-)) was not. In phase 3, the contingency assigning CS(+) and CS(-) was reversed. Conditioned pupil dilation was observed in phase 2 but extinguished in phase 3. MEG revealed that, during phase-2 initial conditioning, the P1m, N1m, and P2m auditory components, measured from sensors over auditory temporal cortex, came to distinguish between CS(+) and CS(-). After contingency reversal in phase 3, the later P2m component rapidly reversed its selectivity (unlike the pupil response) but the earlier P1m did not, whereas N1m showed some new learning but not reversal. These results confirm plasticity of human auditory responses due to classical conditioning, but go further in revealing distinct constraints on different levels of the auditory hierarchy. The later P2m component can reverse affiliation immediately in accord with an updated expectancy after contingency reversal, whereas the earlier auditory components cannot. These findings indicate distinct cognitive and emotional influences on auditory processing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We used magnetoencephalography (MEG) to assess plasticity of human auditory cortex induced by classical conditioning and contingency reversal. Participants listened to random sequences of high or low tones. A first baseline phase presented these without further associations. In phase 2, one of the frequencies (CS(+)) was paired with shock on half its occurrences, whereas the other frequency (CS(-)) was not. In phase 3, the contingency assigning CS(+) and CS(-) was reversed. Conditioned pupil dilation was observed in phase 2 but extinguished in phase 3. MEG revealed that, during phase-2 initial conditioning, the P1m, N1m, and P2m auditory components, measured from sensors over auditory temporal cortex, came to distinguish between CS(+) and CS(-). After contingency reversal in phase 3, the later P2m component rapidly reversed its selectivity (unlike the pupil response) but the earlier P1m did not, whereas N1m showed some new learning but not reversal. These results confirm plasticity of human auditory responses due to classical conditioning, but go further in revealing distinct constraints on different levels of the auditory hierarchy. The later P2m component can reverse affiliation immediately in accord with an updated expectancy after contingency reversal, whereas the earlier auditory components cannot. These findings indicate distinct cognitive and emotional influences on auditory processing. |
Tomas Knapen; Jascha D Swisher; Frank Tong; Patrick Cavanagh Oculomotor remapping of visual information to foveal retinotopic cortex Journal Article Frontiers in Systems Neuroscience, 10 , pp. 1–12, 2016. @article{Knapen2016a, title = {Oculomotor remapping of visual information to foveal retinotopic cortex}, author = {Tomas Knapen and Jascha D Swisher and Frank Tong and Patrick Cavanagh}, doi = {10.3389/fnsys.2016.00054}, year = {2016}, date = {2016-01-01}, journal = {Frontiers in Systems Neuroscience}, volume = {10}, pages = {1--12}, abstract = {Our eyes continually jump around the visual scene to bring the high-resolution, central part of our vision onto objects of interest. We are oblivious to these abrupt shifts, perceiving the visual world to appear reassuringly stable. A process called remapping has been proposed to mediate this perceptual stability for attended objects by shifting their retinotopic representation to compensate for the effects of the upcoming eye movement. In everyday vision, observers make goal-directed eye movements towards items of interest bringing them to the fovea and, for these items, the remapped activity should impinge on foveal regions of the retinotopic maps in visual cortex. Previous research has focused instead on remapping for targets that were not saccade goals, where activity is remapped to a new peripheral location rather than to the foveal representation. We used functional MRI and a phase-encoding design to investigate remapping of spatial patterns of activity towards the fovea/parafovea for saccade targets that were removed prior to completion of the eye movement. We found strong evidence of foveal remapping in retinotopic visual areas, which failed to occur when observers merely attended to the same peripheral target without making eye movements toward it. Significantly, the spatial profile of the remapped response matched the orientation and size of the saccade target, and was appropriately scaled to reflect the retinal extent of the stimulus had it been foveated. We conclude that this remapping of spatially structured information to the fovea may serve as an important mechanism to support our world-centered sense of location across goal-directed eye movements under natural viewing conditions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Our eyes continually jump around the visual scene to bring the high-resolution, central part of our vision onto objects of interest. We are oblivious to these abrupt shifts, perceiving the visual world to appear reassuringly stable. A process called remapping has been proposed to mediate this perceptual stability for attended objects by shifting their retinotopic representation to compensate for the effects of the upcoming eye movement. In everyday vision, observers make goal-directed eye movements towards items of interest bringing them to the fovea and, for these items, the remapped activity should impinge on foveal regions of the retinotopic maps in visual cortex. Previous research has focused instead on remapping for targets that were not saccade goals, where activity is remapped to a new peripheral location rather than to the foveal representation. We used functional MRI and a phase-encoding design to investigate remapping of spatial patterns of activity towards the fovea/parafovea for saccade targets that were removed prior to completion of the eye movement. We found strong evidence of foveal remapping in retinotopic visual areas, which failed to occur when observers merely attended to the same peripheral target without making eye movements toward it. Significantly, the spatial profile of the remapped response matched the orientation and size of the saccade target, and was appropriately scaled to reflect the retinal extent of the stimulus had it been foveated. We conclude that this remapping of spatially structured information to the fovea may serve as an important mechanism to support our world-centered sense of location across goal-directed eye movements under natural viewing conditions. |
Kristin Koller; Christopher M Hatton; Robert D Rogers; Robert D Rafal Stria terminalis microstructure in humans predicts variability in orienting towards threat Journal Article European Journal of Neuroscience, 50 (11), pp. 3804–3813, 2019. @article{Koller2019, title = {Stria terminalis microstructure in humans predicts variability in orienting towards threat}, author = {Kristin Koller and Christopher M Hatton and Robert D Rogers and Robert D Rafal}, doi = {10.1111/ejn.14504}, year = {2019}, date = {2019-07-01}, journal = {European Journal of Neuroscience}, volume = {50}, number = {11}, pages = {3804--3813}, publisher = {Wiley}, abstract = {Current concepts of the extended amygdala posit that basolateral to central amygdala projections mediate fear-conditioned autonomic alerting, whereas projections to the bed nucleus of the stria terminalis mediate sustained anxiety. Using diffusion tensor imaging tractography in humans, we show that microstructure of the stria terminalis correlates with an orienting bias towards threat in a saccade decision task, providing the first evidence that this circuit supports decisions guiding evaluation of threatening stimuli.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Current concepts of the extended amygdala posit that basolateral to central amygdala projections mediate fear-conditioned autonomic alerting, whereas projections to the bed nucleus of the stria terminalis mediate sustained anxiety. Using diffusion tensor imaging tractography in humans, we show that microstructure of the stria terminalis correlates with an orienting bias towards threat in a saccade decision task, providing the first evidence that this circuit supports decisions guiding evaluation of threatening stimuli. |
Tamar Kolodny; Michael Paul Schallmo; Jennifer Gerdts; Raphael A Bernier; Scott O Murray Response dissociation in hierarchical cortical circuits: A unique feature of autism spectrum disorder Journal Article Journal of Neuroscience, 40 (10), pp. 2269–2281, 2020. @article{Kolodny2020, title = {Response dissociation in hierarchical cortical circuits: A unique feature of autism spectrum disorder}, author = {Tamar Kolodny and Michael Paul Schallmo and Jennifer Gerdts and Raphael A Bernier and Scott O Murray}, doi = {10.1523/JNEUROSCI.2376-19.2020}, year = {2020}, date = {2020-01-01}, journal = {Journal of Neuroscience}, volume = {40}, number = {10}, pages = {2269--2281}, abstract = {A prominent hypothesis regarding the pathophysiology of autism is that an increase in the balance between neural excitation and inhibition results in an increase in neural responses. However, previous reports of population-level response magnitude in individuals with autism have been inconsistent. Critically, network interactions have not been considered in previous neuroimaging studies of excitation and inhibition imbalance in autism. In particular, a defining characteristic of cortical organization is its hierarchical and interactive structure; sensory and cognitive systems are comprised of networks where later stages inherit and build upon the processing of earlier input stages, and also influence and shape earlier stages by top-down modulation. Here we used the well established connections of the human visual system to examine response magnitudes in a higher-order motion processing region [middle temporal area (MT+)] and its primary input region (V1). Simple visual stimuli were presented to adult individuals with autism spectrum disorders (ASD; n = 24, mean age 23 years, 8 females) and neurotypical controls (n = 24, mean age 22, 8 females) during fMRI scanning. We discovered a strong dissociation of fMRI response magnitude between region MT+ and V1 in individuals with ASD: individuals with high MT+ responses had attenuated V1 responses. The magnitude of MT+ amplification and of V1 attenuation was associated with autism severity, appeared to result from amplified suppressive feedback from MT+ to V1, and was not present in neurotypical controls. Our results reveal the potential role of altered hierarchical network interactions in the pathophysiology of ASD.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A prominent hypothesis regarding the pathophysiology of autism is that an increase in the balance between neural excitation and inhibition results in an increase in neural responses. However, previous reports of population-level response magnitude in individuals with autism have been inconsistent. Critically, network interactions have not been considered in previous neuroimaging studies of excitation and inhibition imbalance in autism. In particular, a defining characteristic of cortical organization is its hierarchical and interactive structure; sensory and cognitive systems are comprised of networks where later stages inherit and build upon the processing of earlier input stages, and also influence and shape earlier stages by top-down modulation. Here we used the well established connections of the human visual system to examine response magnitudes in a higher-order motion processing region [middle temporal area (MT+)] and its primary input region (V1). Simple visual stimuli were presented to adult individuals with autism spectrum disorders (ASD; n = 24, mean age 23 years, 8 females) and neurotypical controls (n = 24, mean age 22, 8 females) during fMRI scanning. We discovered a strong dissociation of fMRI response magnitude between region MT+ and V1 in individuals with ASD: individuals with high MT+ responses had attenuated V1 responses. The magnitude of MT+ amplification and of V1 attenuation was associated with autism severity, appeared to result from amplified suppressive feedback from MT+ to V1, and was not present in neurotypical controls. Our results reveal the potential role of altered hierarchical network interactions in the pathophysiology of ASD. |
Zoe Kourtzi; Lisa R Betts; Pegah Sarkheil; Andrew E Welchman Distributed neural plasticity for shape learning in the human visual cortex Journal Article PLoS Biology, 3 (7), pp. 1317–1327, 2005. @article{Kourtzi2005, title = {Distributed neural plasticity for shape learning in the human visual cortex}, author = {Zoe Kourtzi and Lisa R Betts and Pegah Sarkheil and Andrew E Welchman}, doi = {10.1371/journal.pbio.0030204}, year = {2005}, date = {2005-01-01}, journal = {PLoS Biology}, volume = {3}, number = {7}, pages = {1317--1327}, abstract = {Expertise in recognizing objects in cluttered scenes is a critical skill for our interactions in complex environments and is thought to develop with learning. However, the neural implementation of object learning across stages of visual analysis in the human brain remains largely unknown. Using combined psychophysics and functional magnetic resonance imaging (fMRI), we show a link between shape-specific learning in cluttered scenes and distributed neuronal plasticity in the human visual cortex. We report stronger fMRI responses for trained than untrained shapes across early and higher visual areas when observers learned to detect low-salience shapes in noisy backgrounds. However, training with high-salience pop-out targets resulted in lower fMRI responses for trained than untrained shapes in higher occipitotemporal areas. These findings suggest that learning of camouflaged shapes is mediated by increasing neural sensitivity across visual areas to bolster target segmentation and feature integration. In contrast, learning of prominent pop-out shapes is mediated by associations at higher occipitotemporal areas that support sparser coding of the critical features for target recognition. We propose that the human brain learns novel objects in complex scenes by reorganizing shape processing across visual areas, while taking advantage of natural image correlations that determine the distinctiveness of target shapes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Expertise in recognizing objects in cluttered scenes is a critical skill for our interactions in complex environments and is thought to develop with learning. However, the neural implementation of object learning across stages of visual analysis in the human brain remains largely unknown. Using combined psychophysics and functional magnetic resonance imaging (fMRI), we show a link between shape-specific learning in cluttered scenes and distributed neuronal plasticity in the human visual cortex. We report stronger fMRI responses for trained than untrained shapes across early and higher visual areas when observers learned to detect low-salience shapes in noisy backgrounds. However, training with high-salience pop-out targets resulted in lower fMRI responses for trained than untrained shapes in higher occipitotemporal areas. These findings suggest that learning of camouflaged shapes is mediated by increasing neural sensitivity across visual areas to bolster target segmentation and feature integration. In contrast, learning of prominent pop-out shapes is mediated by associations at higher occipitotemporal areas that support sparser coding of the critical features for target recognition. We propose that the human brain learns novel objects in complex scenes by reorganizing shape processing across visual areas, while taking advantage of natural image correlations that determine the distinctiveness of target shapes. |
Philip A Kragel; Marianne C Reddan; Kevin S LaBar; Tor D Wager Emotion schemas are embedded in the human visual system Journal Article Science Advances, 5 , pp. eaaw4358, 2019. @article{Kragel2019, title = {Emotion schemas are embedded in the human visual system}, author = {Philip A Kragel and Marianne C Reddan and Kevin S LaBar and Tor D Wager}, doi = {10.1126/sciadv.aaw4358}, year = {2019}, date = {2019-01-01}, journal = {Science Advances}, volume = {5}, pages = {eaaw4358}, abstract = {Theorists have suggested that emotions are canonical responses to situations ancestrally linked to survival. If so, then emotions may be afforded by features of the sensory environment. However, few computational models describe how combinations of stimulus features evoke different emotions. Here, we develop a convolutional neural network that accurately decodes images into 11 distinct emotion categories. We validate the model using more than 25,000 images and movies and show that image content is sufficient to predict the category and valence of human emotion ratings. In two functional magnetic resonance imaging studies, we demonstrate that patterns of human visual cortex activity encode emotion category–related model output and can decode multiple categories of emotional experience. These results suggest that rich, category-specific visual features can be reliably mapped to distinct emotions, and they are coded in distributed representations within the human visual system.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Theorists have suggested that emotions are canonical responses to situations ancestrally linked to survival. If so, then emotions may be afforded by features of the sensory environment. However, few computational models describe how combinations of stimulus features evoke different emotions. Here, we develop a convolutional neural network that accurately decodes images into 11 distinct emotion categories. We validate the model using more than 25,000 images and movies and show that image content is sufficient to predict the category and valence of human emotion ratings. In two functional magnetic resonance imaging studies, we demonstrate that patterns of human visual cortex activity encode emotion category–related model output and can decode multiple categories of emotional experience. These results suggest that rich, category-specific visual features can be reliably mapped to distinct emotions, and they are coded in distributed representations within the human visual system. |
Milosz Krala; Bianca van Kemenade; Benjamin Straube; Tilo Kircher; Frank Bremmer Predictive coding in a multisensory path integration task: An fMRI study Journal Article Journal of vision, 19 (11), pp. 1–15, 2019. @article{Krala2019, title = {Predictive coding in a multisensory path integration task: An fMRI study}, author = {Milosz Krala and Bianca van Kemenade and Benjamin Straube and Tilo Kircher and Frank Bremmer}, doi = {10.1167/19.11.13}, year = {2019}, date = {2019-01-01}, journal = {Journal of vision}, volume = {19}, number = {11}, pages = {1--15}, abstract = {During self-motion through an environment, our sensory systems are confronted with a constant flow of information from different modalities. To successfully navigate, self-induced sensory signals have to be dissociated from externally induced sensory signals. Previous studies have suggested that the processing of self-induced sensory information is modulated by means of predictive coding mechanisms. However, the neural correlates of processing self-induced sensory information from different modalities during self-motion are largely unknown. Here, we asked if and how the processing of visually simulated self-motion and/or associated auditory stimuli is modulated by self-controlled action. Participants were asked to actively reproduce a previously observed simulated self-displacement (path integration). Blood oxygen level-dependent (BOLD) activation during this path integration was compared with BOLD activation during a condition in which we passively replayed the exact sensory stimulus that had been produced by the participants in previous trials. We found supramodal BOLD suppression in parietal and frontal regions. Remarkably, BOLD contrast in sensory areas was enhanced in a modality-specific manner. We conclude that the effect of action on sensory processing is strictly dependent on the respective behavioral task and its relevance.}, keywords = {}, pubstate = {published}, tppubtype = {article} } During self-motion through an environment, our sensory systems are confronted with a constant flow of information from different modalities. To successfully navigate, self-induced sensory signals have to be dissociated from externally induced sensory signals. Previous studies have suggested that the processing of self-induced sensory information is modulated by means of predictive coding mechanisms. However, the neural correlates of processing self-induced sensory information from different modalities during self-motion are largely unknown. Here, we asked if and how the processing of visually simulated self-motion and/or associated auditory stimuli is modulated by self-controlled action. Participants were asked to actively reproduce a previously observed simulated self-displacement (path integration). Blood oxygen level-dependent (BOLD) activation during this path integration was compared with BOLD activation during a condition in which we passively replayed the exact sensory stimulus that had been produced by the participants in previous trials. We found supramodal BOLD suppression in parietal and frontal regions. Remarkably, BOLD contrast in sensory areas was enhanced in a modality-specific manner. We conclude that the effect of action on sensory processing is strictly dependent on the respective behavioral task and its relevance. |
Anna B Kuhns; Pascasie L Dombert; Paola Mengotti; Gereon R Fink; Simone Vossel Spatial attention, motor intention, and Bayesian cue predictability in the human brain Journal Article Journal of Neuroscience, 37 (21), pp. 5334–5344, 2017. @article{Kuhns2017, title = {Spatial attention, motor intention, and Bayesian cue predictability in the human brain}, author = {Anna B Kuhns and Pascasie L Dombert and Paola Mengotti and Gereon R Fink and Simone Vossel}, doi = {10.1523/JNEUROSCI.3255-16.2017}, year = {2017}, date = {2017-01-01}, journal = {Journal of Neuroscience}, volume = {37}, number = {21}, pages = {5334--5344}, abstract = {Predictions about upcoming events influence how we perceive and respond to our environment. There is increasing evidence that predictions may be generated based upon previous observations following Bayesian principles, but little is known about the underlying corticalmechanismsandtheir specificity for different cognitive subsystems.Thepresent studyaimedat identifyingcommonanddistinct neural signatures of predictive processing in the spatial attentional and motor intentional system. Twenty-three female and male healthy human volunteers performed two probabilistic cueing tasks with either spatial or motor cues while lying in the fMRI scanner. In these tasks, the percentage of cue validity changed unpredictably over time. Trialwise estimates of cue predictability were derived from a Bayesian observer model of behavioral responses. These estimates were included as parametric regressors for analyzing the BOLD time series. Parametric effects of cue predictability in valid and invalid trials were considered to reflect belief updating by precision-weighted prediction errors. The brain areas exhibiting predictability-dependent effects dissociated between the spatial attention and motor inten- tion task, with the right temporoparietal cortex being involved during spatial attention and the left angular gyrus and anterior cingulate cortex during motor intention. Connectivity analyses revealed that all three areas showed predictability-dependent coupling with the right hippocampus. These results suggest that precision-weighted prediction errors of stimulus locations and motor responses are encoded in distinct brain regions, but that crosstalk with the hippocampusmaybe necessary to integrate new trialwise outcomes in both cognitive systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Predictions about upcoming events influence how we perceive and respond to our environment. There is increasing evidence that predictions may be generated based upon previous observations following Bayesian principles, but little is known about the underlying corticalmechanismsandtheir specificity for different cognitive subsystems.Thepresent studyaimedat identifyingcommonanddistinct neural signatures of predictive processing in the spatial attentional and motor intentional system. Twenty-three female and male healthy human volunteers performed two probabilistic cueing tasks with either spatial or motor cues while lying in the fMRI scanner. In these tasks, the percentage of cue validity changed unpredictably over time. Trialwise estimates of cue predictability were derived from a Bayesian observer model of behavioral responses. These estimates were included as parametric regressors for analyzing the BOLD time series. Parametric effects of cue predictability in valid and invalid trials were considered to reflect belief updating by precision-weighted prediction errors. The brain areas exhibiting predictability-dependent effects dissociated between the spatial attention and motor inten- tion task, with the right temporoparietal cortex being involved during spatial attention and the left angular gyrus and anterior cingulate cortex during motor intention. Connectivity analyses revealed that all three areas showed predictability-dependent coupling with the right hippocampus. These results suggest that precision-weighted prediction errors of stimulus locations and motor responses are encoded in distinct brain regions, but that crosstalk with the hippocampusmaybe necessary to integrate new trialwise outcomes in both cognitive systems. |
Satwant Kumar; Ivo D Popivanov; Rufin Vogels Transformation of visual representations across ventral stream body-selective patches Journal Article Cerebral Cortex, 29 (1), pp. 215–229, 2019. @article{Kumar2019a, title = {Transformation of visual representations across ventral stream body-selective patches}, author = {Satwant Kumar and Ivo D Popivanov and Rufin Vogels}, doi = {10.1093/cercor/bhx320}, year = {2019}, date = {2019-01-01}, journal = {Cerebral Cortex}, volume = {29}, number = {1}, pages = {215--229}, abstract = {Although the neural processing of visual images of bodies is critical for survival, it is much less well understood than face processing. Functional imaging studies demonstrated body selective regions in primate inferior temporal cortex. To advance our understanding of how the visual brain represents bodies, we compared the representation of animate and inanimate objects in two such body patches with fMRI-guided single unit recordings in rhesus monkeys. We found that the middle Superior Temporal Sulcus body patch (MSB) distinguishes to a greater extent bodies from non-bodies than the anterior Superior Temporal Sulcus body patch (ASB). Importantly, ASB carried more viewpoint-tolerant information about body posture and body identity than MSB, while MSB showed greater orientation selectivity. Combined with previous work on faces, this suggests that an increase in view-tolerant representations, coupled with a refined individuation, along the visual hierarchy is a general property of information processing within the inferior temporal cortex.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Although the neural processing of visual images of bodies is critical for survival, it is much less well understood than face processing. Functional imaging studies demonstrated body selective regions in primate inferior temporal cortex. To advance our understanding of how the visual brain represents bodies, we compared the representation of animate and inanimate objects in two such body patches with fMRI-guided single unit recordings in rhesus monkeys. We found that the middle Superior Temporal Sulcus body patch (MSB) distinguishes to a greater extent bodies from non-bodies than the anterior Superior Temporal Sulcus body patch (ASB). Importantly, ASB carried more viewpoint-tolerant information about body posture and body identity than MSB, while MSB showed greater orientation selectivity. Combined with previous work on faces, this suggests that an increase in view-tolerant representations, coupled with a refined individuation, along the visual hierarchy is a general property of information processing within the inferior temporal cortex. |
Eline R Kupers; Helena X Wang; Kaoru Amano; Kendrick N Kay; David J Heeger; Jonathan Winawer A non-invasive, quantitative study of broadband spectral responses in human visual cortex Journal Article PLoS ONE, 13 (3), pp. e0193107, 2018. @article{Kupers2018, title = {A non-invasive, quantitative study of broadband spectral responses in human visual cortex}, author = {Eline R Kupers and Helena X Wang and Kaoru Amano and Kendrick N Kay and David J Heeger and Jonathan Winawer}, doi = {10.1371/journal.pone.0193107}, year = {2018}, date = {2018-01-01}, journal = {PLoS ONE}, volume = {13}, number = {3}, pages = {e0193107}, abstract = {Currently, non-invasive methods for studying the human brain do not routinely and reliably measure spike-rate-dependent signals, independent of responses such as hemodynamic coupling (fMRI) and subthreshold neuronal synchrony (oscillations and event-related potentials). In contrast, invasive methods-microelectrode recordings and electrocorticography (ECoG)-have recently measured broadband power elevation in field potentials (~50-200 Hz) as a proxy for locally averaged spike rates. Here, we sought to detect and quantify stimulus-related broadband responses using magnetoencephalography (MEG). Extracranial measurements like MEG and EEG have multiple global noise sources and relatively low signal-to-noise ratios; moreover high frequency artifacts from eye movements can be confounded with stimulus design and mistaken for signals originating from brain activity. For these reasons, we developed an automated denoising technique that helps reveal the broadband signal of interest. Subjects viewed 12-Hz contrast-reversing patterns in the left, right, or bilateral visual field. Sensor time series were separated into evoked (12-Hz amplitude) and broadband components (60-150 Hz). In all subjects, denoised broadband responses were reliably measured in sensors over occipital cortex, even in trials without microsaccades. The broadband pattern was stimulus-dependent, with greater power contralateral to the stimulus. Because we obtain reliable broadband estimates with short experiments (~20 minutes), and with sufficient signal-to-noise to distinguish responses to different stimuli, we conclude that MEG broadband signals, denoised with our method, offer a practical, non-invasive means for characterizing spike-rate-dependent neural activity for addressing scientific questions about human brain function.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Currently, non-invasive methods for studying the human brain do not routinely and reliably measure spike-rate-dependent signals, independent of responses such as hemodynamic coupling (fMRI) and subthreshold neuronal synchrony (oscillations and event-related potentials). In contrast, invasive methods-microelectrode recordings and electrocorticography (ECoG)-have recently measured broadband power elevation in field potentials (~50-200 Hz) as a proxy for locally averaged spike rates. Here, we sought to detect and quantify stimulus-related broadband responses using magnetoencephalography (MEG). Extracranial measurements like MEG and EEG have multiple global noise sources and relatively low signal-to-noise ratios; moreover high frequency artifacts from eye movements can be confounded with stimulus design and mistaken for signals originating from brain activity. For these reasons, we developed an automated denoising technique that helps reveal the broadband signal of interest. Subjects viewed 12-Hz contrast-reversing patterns in the left, right, or bilateral visual field. Sensor time series were separated into evoked (12-Hz amplitude) and broadband components (60-150 Hz). In all subjects, denoised broadband responses were reliably measured in sensors over occipital cortex, even in trials without microsaccades. The broadband pattern was stimulus-dependent, with greater power contralateral to the stimulus. Because we obtain reliable broadband estimates with short experiments (~20 minutes), and with sufficient signal-to-noise to distinguish responses to different stimuli, we conclude that MEG broadband signals, denoised with our method, offer a practical, non-invasive means for characterizing spike-rate-dependent neural activity for addressing scientific questions about human brain function. |
Juha M Lahnakoski; Enrico Glerean; Iiro P Jääskeläinen; Jukka Hyönä; Riitta Hari; Mikko Sams; Lauri Nummenmaa Synchronous brain activity across individuals underlies shared psychological perspectives Journal Article NeuroImage, 100 , pp. 316–324, 2014. @article{Lahnakoski2014, title = {Synchronous brain activity across individuals underlies shared psychological perspectives}, author = {Juha M Lahnakoski and Enrico Glerean and Iiro P Jääskeläinen and Jukka Hyönä and Riitta Hari and Mikko Sams and Lauri Nummenmaa}, doi = {10.1016/j.neuroimage.2014.06.022}, year = {2014}, date = {2014-01-01}, journal = {NeuroImage}, volume = {100}, pages = {316--324}, publisher = {Elsevier B.V.}, abstract = {For successful communication, we need to understand the external world consistently with others. This task requires sufficiently similar cognitive schemas or psychological perspectives that act as filters to guide the selection, interpretation and storage of sensory information, perceptual objects and events. Here we show that when individuals adopt a similar psychological perspective during natural viewing, their brain activity becomes synchronized in specific brain regions. We measured brain activity with functional magnetic resonance imaging (fMRI) from 33 healthy participants who viewed a 10-min movie twice, assuming once a 'social' (detective) and once a 'non-social' (interior decorator) perspective to the movie events. Pearson's correlation coefficient was used to derive multisubject voxelwise similarity measures (inter-subject correlations; ISCs) of functional MRI data. We used k-nearest-neighbor and support vector machine classifiers as well as a Mantel test on the ISC matrices to reveal brain areas wherein ISC predicted the participants' current perspective. ISC was stronger in several brain regions-most robustly in the parahippocampal gyrus, posterior parietal cortex and lateral occipital cortex-when the participants viewed the movie with similar rather than different perspectives. Synchronization was not explained by differences in visual sampling of the movies, as estimated by eye gaze. We propose that synchronous brain activity across individuals adopting similar psychological perspectives could be an important neural mechanism supporting shared understanding of the environment.}, keywords = {}, pubstate = {published}, tppubtype = {article} } For successful communication, we need to understand the external world consistently with others. This task requires sufficiently similar cognitive schemas or psychological perspectives that act as filters to guide the selection, interpretation and storage of sensory information, perceptual objects and events. Here we show that when individuals adopt a similar psychological perspective during natural viewing, their brain activity becomes synchronized in specific brain regions. We measured brain activity with functional magnetic resonance imaging (fMRI) from 33 healthy participants who viewed a 10-min movie twice, assuming once a 'social' (detective) and once a 'non-social' (interior decorator) perspective to the movie events. Pearson's correlation coefficient was used to derive multisubject voxelwise similarity measures (inter-subject correlations; ISCs) of functional MRI data. We used k-nearest-neighbor and support vector machine classifiers as well as a Mantel test on the ISC matrices to reveal brain areas wherein ISC predicted the participants' current perspective. ISC was stronger in several brain regions-most robustly in the parahippocampal gyrus, posterior parietal cortex and lateral occipital cortex-when the participants viewed the movie with similar rather than different perspectives. Synchronization was not explained by differences in visual sampling of the movies, as estimated by eye gaze. We propose that synchronous brain activity across individuals adopting similar psychological perspectives could be an important neural mechanism supporting shared understanding of the environment. |
Stephanie J Larcombe; Christopher Kennard; Holly Bridge Increase in MST activity correlates with visual motion learning: A functional MRI study of perceptual learning Journal Article Human Brain Mapping, 39 (1), pp. 145–156, 2018. @article{Larcombe2018, title = {Increase in MST activity correlates with visual motion learning: A functional MRI study of perceptual learning}, author = {Stephanie J Larcombe and Christopher Kennard and Holly Bridge}, doi = {10.1002/hbm.23832}, year = {2018}, date = {2018-01-01}, journal = {Human Brain Mapping}, volume = {39}, number = {1}, pages = {145--156}, abstract = {Repeated practice of a specific task can improve visual performance, but the neural mechanisms underlying this improvement in performance are not yet well understood. Here we trained healthy partici- pants on a visual motion task daily for 5 days in one visual hemifield. Before and after training, we used functional magnetic resonance imaging (fMRI) to measure the change in neural activity. We also imaged a control group of participants on two occasions who did not receive any task training. While in the MRI scanner, all participants completed the motion task in the trained and untrained visual hemifields sepa- rately. Following training, participants improved their ability to discriminate motion direction in the trained hemifield and, to a lesser extent, in the untrained hemifield. The amount of task learning correlated positively with the change in activity in the medial superior temporal (MST) area. MST is the anterior por- tion of the human motion complex (hMT1). MST changes were localized to the hemisphere contralateral to the region of the visual field, where perceptual training was delivered. Visual areas V2 and V3a showed an increase in activity between the first and second scan in the training group, but this was not correlated with performance. The contralateral anterior hippocampus and bilateral dorsolateral prefrontal cortex (DLPFC) and frontal pole showed changes in neural activity that also correlated with the amount of task learning. These findings emphasize the importance of MST in perceptual learning of a visual motion task.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Repeated practice of a specific task can improve visual performance, but the neural mechanisms underlying this improvement in performance are not yet well understood. Here we trained healthy partici- pants on a visual motion task daily for 5 days in one visual hemifield. Before and after training, we used functional magnetic resonance imaging (fMRI) to measure the change in neural activity. We also imaged a control group of participants on two occasions who did not receive any task training. While in the MRI scanner, all participants completed the motion task in the trained and untrained visual hemifields sepa- rately. Following training, participants improved their ability to discriminate motion direction in the trained hemifield and, to a lesser extent, in the untrained hemifield. The amount of task learning correlated positively with the change in activity in the medial superior temporal (MST) area. MST is the anterior por- tion of the human motion complex (hMT1). MST changes were localized to the hemisphere contralateral to the region of the visual field, where perceptual training was delivered. Visual areas V2 and V3a showed an increase in activity between the first and second scan in the training group, but this was not correlated with performance. The contralateral anterior hippocampus and bilateral dorsolateral prefrontal cortex (DLPFC) and frontal pole showed changes in neural activity that also correlated with the amount of task learning. These findings emphasize the importance of MST in perceptual learning of a visual motion task. |
Rebecca P Lawson; Ben Seymour; Eleanor Loh; Antoine Lutti; Raymond J Dolan; Peter Dayan; Nikolaus Weiskopf; Jonathan P Roiser The habenula encodes negative motivational value associated with primary punishment in humans Journal Article Proceedings of the National Academy of Sciences, 111 (32), pp. 11858–11863, 2014. @article{Lawson2014, title = {The habenula encodes negative motivational value associated with primary punishment in humans}, author = {Rebecca P Lawson and Ben Seymour and Eleanor Loh and Antoine Lutti and Raymond J Dolan and Peter Dayan and Nikolaus Weiskopf and Jonathan P Roiser}, doi = {10.1073/pnas.1323586111}, year = {2014}, date = {2014-01-01}, journal = {Proceedings of the National Academy of Sciences}, volume = {111}, number = {32}, pages = {11858--11863}, abstract = {Learning what to approach, and what to avoid, involves assigning value to environmental cues that predict positive and negative events. Studies in animals indicate that the lateral habenula encodes the previously learned negative motivational value of stimuli. However, involvement of the habenula in dynamic trial-by-trial aversive learning has not been assessed, and the functional role of this structure in humans remains poorly characterized, in part, due to its small size. Using high-resolution functional neuroimaging and computational modeling of reinforcement learning, we demonstrate positive habenula responses to the dynamically changing values of cues signaling painful electric shocks, which predict behavioral suppression of responses to those cues across individuals. By contrast, negative habenula responses to monetary reward cue values predict behavioral invigoration. Our findings show that the habenula plays a key role in an online aversive learning system and in generating associated motivated behavior in humans.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Learning what to approach, and what to avoid, involves assigning value to environmental cues that predict positive and negative events. Studies in animals indicate that the lateral habenula encodes the previously learned negative motivational value of stimuli. However, involvement of the habenula in dynamic trial-by-trial aversive learning has not been assessed, and the functional role of this structure in humans remains poorly characterized, in part, due to its small size. Using high-resolution functional neuroimaging and computational modeling of reinforcement learning, we demonstrate positive habenula responses to the dynamically changing values of cues signaling painful electric shocks, which predict behavioral suppression of responses to those cues across individuals. By contrast, negative habenula responses to monetary reward cue values predict behavioral invigoration. Our findings show that the habenula plays a key role in an online aversive learning system and in generating associated motivated behavior in humans. |
Adrian K C Lee; Siddharth Rajaram; Jing Xia; Hari Bharadwaj; Eric D Larson; Matti S Hämäläinen; Barbara G Shinn-Cunningham Auditory selective attention reveals preparatory activity in different cortical regions for selection based on source location and source pitch Journal Article Frontiers in Neuroscience, 6 , pp. 1–9, 2013. @article{Lee2013b, title = {Auditory selective attention reveals preparatory activity in different cortical regions for selection based on source location and source pitch}, author = {Adrian K C Lee and Siddharth Rajaram and Jing Xia and Hari Bharadwaj and Eric D Larson and Matti S Hämäläinen and Barbara G Shinn-Cunningham}, doi = {10.3389/fnins.2012.00190}, year = {2013}, date = {2013-01-01}, journal = {Frontiers in Neuroscience}, volume = {6}, pages = {1--9}, abstract = {In order to extract information in a rich environment, we focus on different features that allow us to direct attention to whatever source is of interest. The cortical network deployed during spatial attention, especially in vision, is well characterized. For example, visuospatial attention engages a frontoparietal network including the frontal eye fields (FEFs), which modulate activity in visual sensory areas to enhance the representation of an attended visual object. However, relatively little is known about the neural circuitry controlling attention directed to non-spatial features, or to auditory objects or features (either spatial or non-spatial). Here, using combined magnetoencephalography (MEG) and anatomical information obtained from MRI, we contrasted cortical activity when observers attended to different auditory features given the same acoustic mixture of two simultaneous spoken digits. Leveraging the fine temporal resolution of MEG, we establish that activity in left FEF is enhanced both prior to and throughout the auditory stimulus when listeners direct auditory attention to target location compared to when they focus on target pitch. In contrast, activity in the left posterior superior temporal sulcus (STS), a region previously associated with auditory pitch categorization, is greater when listeners direct attention to target pitch rather than target location. This differential enhancement is only significant after observers are instructed which cue to attend, but before the acoustic stimuli begin. We therefore argue that left FEF participates more strongly in directing auditory spatial attention, while the left STS aids auditory object selection based on the non-spatial acoustic feature of pitch.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In order to extract information in a rich environment, we focus on different features that allow us to direct attention to whatever source is of interest. The cortical network deployed during spatial attention, especially in vision, is well characterized. For example, visuospatial attention engages a frontoparietal network including the frontal eye fields (FEFs), which modulate activity in visual sensory areas to enhance the representation of an attended visual object. However, relatively little is known about the neural circuitry controlling attention directed to non-spatial features, or to auditory objects or features (either spatial or non-spatial). Here, using combined magnetoencephalography (MEG) and anatomical information obtained from MRI, we contrasted cortical activity when observers attended to different auditory features given the same acoustic mixture of two simultaneous spoken digits. Leveraging the fine temporal resolution of MEG, we establish that activity in left FEF is enhanced both prior to and throughout the auditory stimulus when listeners direct auditory attention to target location compared to when they focus on target pitch. In contrast, activity in the left posterior superior temporal sulcus (STS), a region previously associated with auditory pitch categorization, is greater when listeners direct attention to target pitch rather than target location. This differential enhancement is only significant after observers are instructed which cue to attend, but before the acoustic stimuli begin. We therefore argue that left FEF participates more strongly in directing auditory spatial attention, while the left STS aids auditory object selection based on the non-spatial acoustic feature of pitch. |