Dimitris Agrafiotis; Nishan Canagarajah; David R Bull; Matthew Dye
In: Electronics Letters, vol. 39, pp. 1–2, 2003.
A perceptually optimised approach to sign language video coding is presented. The proposed approach is based on the results (included) of an eye tracking study in the visual attention of sign language viewers. Results show reductions in bit rate of over 30% with very good subjective quality.
Dimitris Agrafiotis; Nishan Canagarajah; David R Bull; Jim Kyle; Helen Seers; Matthew Dye
In: Signal Processing: Image Communication, vol. 21, no. 7, pp. 531–549, 2006.
The ability to communicate remotely through the use of video as promised by wireless networks and already practised over fixed networks, is for deaf people as important as voice telephony is for hearing people. Sign languages are visual-spatial languages and as such demand good image quality for interaction and understanding. In this paper, we first analyse the sign language viewer's eye-gaze, based on the results of an eye-tracking study that we conducted, as well as the video content involved in sign language person-to-person communication. Based on this analysis we propose a sign language video coding system using foveated processing, which can lead to bit rate savings without compromising the comprehension of the coded sequence or equivalently produce a coded sequence with higher comprehension value at the same bit rate. We support this claim with the results of an initial comprehension assessment trial of such coded sequences by deaf users. The proposed system constitutes a new paradigm for coding sign language image sequences at limited bit rates. textcopyright 2006 Elsevier B.V. All rights reserved.
Byunghoon “Tony” Ahn; Jason M Harley
In: British Journal of Educational Technology, vol. 51, no. 5, pp. 1563–1576, 2020.
Learning analytics (LA) incorporates analyzing cognitive, social and emotional processes in learning scenarios to make informed decisions regarding instructional design and delivery. Research has highlighted important roles that emotions play in learning. We have extended this field of research by exploring the role of emotions in a relatively uncommon learning scenario: learning about queer history with a multimedia mobile app. Specifically, we used an automatic facial recognition software (FaceReader 7) to measure learners' discrete emotions and a counter-balanced multiple-choice quiz to assess learning. We also used an eye tracker (EyeLink 1000) to identify the emotions learners experienced while they read specific content, as opposed to the emotions they experienced over the course of the entire learning session. A total of 33 out of 57 of the learners' data were eligible to be analyzed. Results revealed that learners expressed more negative-activating emotions (ie, anger, anxiety) and negative-deactivating emotions (ie, sadness) than positive-activating emotions (ie, happiness). Learners with an angry emotion profile had the highest learning gains. The importance of examining typically undesirable emotions in learning, such as anger, is discussed using the control-value theory of achievement emotions. Further, this study describes a multimodal methodology to integrate behavioral trace data into learning analytics research.
Avigael M Aizenman; Trafton Drew; Krista A Ehinger; Dianne Georgian-smith; Jeremy M Wolfe
In: Journal of Medical Imaging, vol. 4, no. 4, pp. 1–22, 2017.
As a promising imaging modality, digital breast tomosynthesis (DBT) leads to better diagnostic per- formance than traditional full-field digital mammograms (FFDM) alone. DBT allows different planes of the breast to be visualized, reducing occlusion from overlapping tissue. Although DBT is gaining popularity, best practices for search strategies in this medium are unclear. Eye tracking allowed us to describe search patterns adopted by radiologists searching DBT and FFDM images. Eleven radiologists examined eight DBT and FFDM cases. Observers marked suspicious masses with mouse clicks. Eye position was recorded at 1000 Hz and was coregistered with slice/depth plane as the radiologist scrolled through the DBT images, allowing a 3-D representation of eye position. Hit rate for masses was higher for tomography cases than 2-D cases and DBT led to lower false positive rates. However, search duration was much longer for DBT cases than FFDM. DBT was associated with longer fixations but similar saccadic amplitude compared with FFDM. When comparing radiologists' eye movements to a previous study, which tracked eye movements as radiologists read chest CT, we found DBT viewers did not align with previously identified “driller” or “scanner” strategies, although their search strategy most closely aligns with a type of vigorous drilling strategy.
Eye and Pen: A new device for studying reading Journal Article
In: Behavior Research Methods, vol. 38, no. 2, pp. 287–299, 2006.
We present a new method for studying reading during writing and the relationships between these two activities. the Eye and Pen device makes a synchronous recording of handwriting and eye move- ments during written composition. it complements existing online methods by providing a fine-grained description of the visual information fixated during pauses as well as during the actual writing act. this device can contribute to the exploration of several research issues, since it can be used to investigate the role of the text produced so far and the documentary sources displayed in the task environment. the study of the engagement of reading during writing should provide important information about the dynamics of writing processes based on visual information. Written
Hani Alers; Judith A Redi; Ingrid Heynderickx
In: Signal Processing: Image Communication, vol. 32, pp. 69–80, 2015.
Advances in digital technology have allowed us to embed significant processing power in everyday video consumption devices. At the same time, we have placed high demands on the video content itself by continuing to increase spatial resolution while trying to limit the allocated file size and bandwidth as much as possible. The result is typically a trade-off between perceptual quality and fulfillment of technological limitations. To bring this trade-off to its optimum, it is necessary to understand better how people perceive video quality. In this work, we particularly focus on understanding how the spatial location of compression artifacts impacts visual quality perception, and specifically in relation with visual attention. In particular we investigate how changing the quality of the region of interest of a video affects its overall perceived quality, and we quantify the importance of the visual quality of the region of interest to the overall quality judgment. A three stage experiment was conducted where viewers were shown videos with different quality levels in different parts of the scene. By asking them to score the overall quality we found that the quality of the region of interest has 10 times more impact than the quality of the rest of the scene. These results are in line with similar effects observed in still images, yet in videos the relevance of the visual quality of the region of interest is twice as high than in images. The latter finding is directly relevant for the design of more accurate objective quality metrics for videos, that are based on the estimation of local distortion visibility.
Hosam Al-Samarraie; Samer Muthana Sarsam; Hans Guesgen
In: Behaviour and Information Technology, vol. 35, no. 8, pp. 644–653, 2016.
It is a well-known fact that users vary in their preferences and needs. Therefore, it is very crucial to provide the customisation or personalisation for users in certain usage conditions that are more associated with their preferences. With the current limitation in adopting perceptual processing into user interface personalisation, we introduced the possibility of inferring interface design preferences from the user?s eye-movement behaviour. We firstly captured the user?s preferences of graphic design elements using an eye-tracker. Then we diagnosed these preferences towards the region of interests to build a prediction model for interface customisation. The prediction models from eye-movement behaviour showed a high potential for predicting users? preferences of interface design based on the paralleled relation between their fixation and saccadic movement. This mechanism provides a novel way of user interface design customisation and opens the door for new research in the areas of human?computer interaction and decision-making.
George J Andersen; Rui Ni; Zheng Bian; Julie Kang
In: Accident Analysis & Prevention, vol. 43, no. 1, pp. 381–390, 2011.
The present study examined the limits of spatial attention while performing two driving relevant tasks that varied in depth. The first task was to maintain a fixed headway distance behind a lead vehicle that varied speed. The second task was to detect a light-change target in an array of lights located above the roadway. In Experiment 1 the light detection task required drivers to encode color and location. The results indicated that reaction time to detect a light-change target increased and accuracy decreased as a function of the horizontal location of the light-change target and as a function of the distance from the driver. In a second experiment the light change task was changed to a singleton search (detect the onset of a yellow light) and the workload of the car following task was systematically varied. The results of Experiment 2 indicated that RT increased as a function of task workload, the 2D position of the light-change target and the distance of the light-change target. A multiple regression analysis indicated that the effect of distance on light detection performance was not due to changes in the projected size of the light target. In Experiment 3 we found that the distance effect in detecting a light change could not be explained by the location of eye fixations. The results demonstrate that when drivers attend to a roadway scene attention is limited in three-dimensional space. These results have important implications for developing tests for assessing crash risk among drivers as well as the design of in vehicle technologies such as head-up displays.
Nicola C Anderson; Evan F Risko; Alan Kingstone
Exploiting human sensitivity to gaze for tracking the eyes Journal Article
In: Behavior Research Methods, vol. 43, pp. 843–852, 2011.
Given the prevalence, quality, and low cost of web cameras, along with the remarkable human sensitivity to gaze, we examined the accuracy of eye tracking using only a web camera. Participants were shown webcamera recordings of a person's eyes moving 1°, 2°, or 3° of visual angle in one of eight radial directions (north, northeast, east, southeast, etc.), or no eye movement occurred at all. Observers judged whether an eye movement was made and, if so, its direction. Our findings demonstrate that for all saccades of any size or direction, observers can detect and discriminate eye movements significantly better than chance. Critically, the larger the saccade, the better the judgments, so that for eye movements of 3°, people can tell whether an eye movement occurred, and where it was going, at about 90% or better. This simple methodology of using a web camera and looking for eye movements offers researchers a simple, reliable, and cost-effective research tool that can be applied effectively both in studies where it is important that participants maintain central fixation (e.g., covert attention investigations) and in those where they are free or required to move their eyes (e.g., visual search).
Janice Attard; Markus Bindemann
In: Applied Cognitive Psychology, vol. 28, no. 2, pp. 215–225, 2014.
The time available for viewing a perpetrator at a crime scene predicts successful person recognition in subsequent identity line-ups. This time is usually unknown and must be derived from eyewitnesses' duration estimates. This study therefore compared the estimates that different individuals provide for crimes. We then attempted to determine the accuracy of these durations by measuring observers' general time estimation ability with a set of estimator videos. Observers differed greatly in their ability to estimate time, but individual duration estimates correlated strongly for crime and estimator materials. This indicates that it might be possible to infer unknown durations of events, such as criminal incidents, from a person's ability to estimate known durations. We also measured observers' eye movements to a perpetrator during crimes. Only fixations on a perpetrator's face related to eyewitness accuracy, but these fixations did not correlate with exposure estimates for this person. The implications of these findings are discussed.
Hamidreza Azemati; Fatemeh Jam; Modjtaba Ghorbani; Matthias Dehmer; Reza Ebrahimpour; Abdolhamid Ghanbaran; Frank Emmert-Streib
In: Symmetry, vol. 12, pp. 1–15, 2020.
Symmetry is an important visual feature for humans and its application in architecture is completely evident. This paper aims to investigate the role of symmetry in the aesthetics judgment of residential building façades and study the pattern of eye movement based on the expertise of subjects in architecture. In order to implement this in the present paper, we have created images in two categories: symmetrical and asymmetrical façade images. The experiment design allows us to investigate the preference of subjects and their reaction time to decide about presented images as well as record their eye movements. It was inferred that the aesthetic experience of a building façade is influenced by the expertise of the subjects. There is a significant difference between experts and non-experts in all conditions, and symmetrical façades are in line with the taste of non-expert subjects. Moreover, the patterns of fixational eye movements indicate that the horizontal or vertical symmetry (mirror symmetry) has a profound influence on the observer's attention, but there is a difference in the points watched and their fixation duration. Thus, although symmetry may attract the same attention during eye movements on façade images, it does not necessarily lead to the same preference between the expert and non-expert groups.
Elham Azizi; Larry Allen Abel; Matthew J Stainer
In: Attention, Perception, and Psychophysics, vol. 79, no. 2, pp. 484–497, 2017.
Action game playing has been associated with several improvements in visual attention tasks. However, it is not clear how such changes might influence the way we overtly select information from our visual world (i.e. eye movements). We examined whether action-video-game training changed eye movement behaviour in a series of visual search tasks including conjunctive search (relatively abstracted from natural behaviour), game-related search, and more naturalistic scene search. Forty nongamers were trained in either an action first-person shooter game or a card game (control) for 10 hours. As a further control, we recorded eye movements of 20 experienced action gamers on the same tasks. The results did not show any change in duration of fixations or saccade amplitude either from before to after the training or between all nongamers (pretraining) and experienced action gamers. However, we observed a change in search strategy, reflected by a reduction in the vertical distribution of fixations for the game-related search task in the action-game-trained group. This might suggest learning the likely distribution of targets. In other words, game training only skilled participants to search game images for targets important to the game, with no indication of transfer to the more natural scene search. Taken together, these results suggest no modification in overt allocation of attention. Either the skills that can be trained with action gaming are not powerful enough to influence information selection through eye movements, or action-game-learned skills are not used when deciding where to move the eyes.
D A Baker; N J Schweitzer; Evan F Risko; Jillian M Ware
Visual attention and the neuroimage bias Journal Article
In: PLoS ONE, vol. 8, no. 9, pp. e74449, 2013.
Several highly-cited experiments have presented evidence suggesting that neuroimages may unduly bias laypeople's judgments of scientific research. This finding has been especially worrisome to the legal community in which neuroimage techniques may be used to produce evidence of a person's mental state. However, a more recent body of work that has looked directly at the independent impact of neuroimages on layperson decision-making (both in legal and more general arenas), and has failed to find evidence of bias. To help resolve these conflicting findings, this research uses eye tracking technology to provide a measure of attention to different visual representations of neuroscientific data. Finding an effect of neuroimages on the distribution of attention would provide a potential mechanism for the influence of neuroimages on higher-level decisions. In the present experiment, a sample of laypeople viewed a vignette that briefly described a court case in which the defendant's actions might have been explained by a neurological defect. Accompanying these vignettes was either an MRI image of the defendant's brain, or a bar graph depicting levels of brain activity-two competing visualizations that have been the focus of much of the previous research on the neuroimage bias. We found that, while laypeople differentially attended to neuroimagery relative to the bar graph, this did not translate into differential judgments in a way that would support the idea of a neuroimage bias.
Ana Margarida Barreto
Do users look at banner ads on Facebook? Journal Article
In: Journal of Research in Interactive Marketing, vol. 7, no. 2, pp. 119–139, 2013.
Purpose – The main purpose of this study was to determine whether users of the online social network site, Facebook, actually look at the ads displayed (briefly, to test the existence of the phenomenon known as “banner blindness” in this website), thus ascertaining the effectiveness of paid advertising, and comparing it with the number of friends' recommendations seen. Design/methodology/approach – In order to achieve this goal, an experiment using eye-tracking technology was administered to a total of 20 participants from a major university in the USA, followed by a questionnaire. Findings – Findings show that online ads attract less attention levels than friends' recommendations. A possible explanation for this phenomenon may be related to the fact that ads on Facebook are outside of the F-shaped visual pattern range, causing a state of “banner blindness”. Results also show that statistically there is no difference in ads seen and clicked between women and men. Research limitations/implications – The sample type (undergraduate and graduate students) and the sample size (20 participants) inhibit the generalization of the findings to other populations. Practical implications – The paper includes implications for the development of an effective online advertising campaign, as well as some proposed conceptualizations of the terms social network site and advertising, which can be used as platforms for discussion or as standards for future definitions. Originality/value – This study fulfils some identified needs to study advertising effectiveness based on empirical data and to assess banner blindness in other contexts, representative of current internet users' habits.
Joseph E Barton; Anindo Roy; John D Sorkin; Mark W Rogers; Richard F Macko
In: Journal of Biomechanical Engineering, vol. 138, no. 1, pp. 1–11, 2016.
We developed a balance measurement tool (the balanced reach test (BRT)) to assess standing balance while reaching and pointing to a target moving in three-dimensional space according to a sum-of-sines function. We also developed a three-dimensional, 13-segment biomechanical model to analyze performance in this task. Using kinematic and ground reaction force (GRF) data from the BRT, we performed an inverse dynamics analysis to compute the forces and torques applied at each of the joints during the course of a 90 s test. We also performed spectral analyses of each joint's force activations. We found that the joints act in a different but highly coordinated manner to accomplish the tracking task-with individual joints responding congruently to different portions of the target disk's frequency spectrum. The test and the model also identified clear differences between a young healthy subject (YHS), an older high fall risk (HFR) subject before participating in a balance training intervention; and in the older subject's performance after training (which improved to the point that his performance approached that of the young subject). This is the first phase of an effort to model the balance control system with sufficient physiological detail and complexity to accurately simulate the multisegmental control of balance during functional reach across the spectra of aging, medical, and neurological conditions that affect performance. Such a model would provide insight into the function and interaction of the biomechanical and neurophysiological elements making up this system; and system adaptations to changes in these elements' performance and capabilities.
Visual qualities of future geography books Journal Article
In: European Journal of Geography, vol. 5, no. 4, pp. 56–66, 2014.
The capacity for spatial orientation and associated faculties are closely related to visual competencies. Consequently, the practice and acquisition of visual competencies are vital prerequisites to successful learning and teaching of geography. Today, geography can be understood as a visual discipline and as such may develop strong links to visual communication. In geography, textbooks may establish this link in an everyday context. This Ph.D. project aims to build the bridge between subject content and design. The result will be a visually convincing geography textbook prototype. Fifty-six geography textbooks from different European countries were analysed, focussing on the design concept. Furthermore, double-page spreads of current German geography textbooks were evaluated by observing students' textbook usage via eye tracking. Eye tracking monitors students' reactions to varying contents and designs. Findings from both analyses form the basis for the textbook concept, which is to be developed.
In: Nordidactica – Journal of Humanities and Social Science Education, vol. 1, pp. 38–62, 2016.
This paper investigates how textbook design may influence students' visual attention to graphics, photos and text in current geography textbooks. Eye tracking, a visual method of data collection and analysis, was utilised to precisely monitor students' eye movements while observing geography textbook spreads. In an exploratory study utilising random sampling, the eye movements of 20 students (secondary school students 15–17 years of age and university students 20–24 years of age) were recorded. The research entities were double- page spreads of current German geography textbooks covering an identical topic, taken from five separate textbooks. A two-stage test was developed. Each participant was given the task of first looking at the entire textbook spread to determine what was being explained on the pages. In the second stage, participants solved one of the tasks from the exercise section. Overall, each participant studied five different textbook spreads and completed five set tasks. After the eye tracking study, each participant completed a questionnaire. The results may verify textbook design as one crucial factor for successful knowledge acquisition from textbooks. Based on the eye tracking documentation, learning-related challenges posed by images and complex image-text structures in textbooks are elucidated and related to educational psychology insights and findings from visual communication and textbook analysis.
Palash Bera; Louis Philippe Sirois
Displaying background maps in business intelligence dashboards Journal Article
In: Iranian Journal of Psychiatry, vol. 18, no. 5, pp. 58–65, 2016.
Business data in geographic maps, called data maps, can be displayed via business intelligence dashboards. An important emerging feature is the use of background maps that overlap with existing data maps. Here, the authors examine the usefulness of background maps in dashboards and investigate how much cognitive effort users put in when they use dashboards with background maps as compared to dashboards without them. To test the extent of cognitive effort, the authors conducted an eye-tracking study in which users performed a decision-making task with maps in dashboards. In a separate study, users were asked directly about the mental effort required to perform tasks with the dashboards. Both studies identified that when users use background maps, they required less cognitive effort than users who use dashboards in which the information on the background map is represented in another form, such as a bar chart.
Erin Berenbaum; Amy E Latimer-Cheung
In: Journal of Sport and Exercise Psychology, vol. 36, no. 3, pp. 271–280, 2014.
Gain-framed messages are more effective at promoting physical activity than loss-framed messages. However, the mechanism through which this effect occurs is unclear. The current experiment examined the effects of message framing on variables described in the communication behavior change model (McGuire, 1989), as well as the mediating effects of these variables on the message-frame-behavior relationship. Sixty low-to-moderately active women viewed 20 gain- or loss-framed ads and five control ads while their eye movements were recorded via eye tracking. The gain-framed ads attracted greater attention, ps textless .05; produced more positive attitudes
Raymond Bertram; Laura Helle; Johanna K Kaakinen; Erkki Svedström
In: PLoS ONE, vol. 8, no. 6, pp. e66169, 2013.
The present eye-movement study assessed the effect of expertise on eye-movement behaviour during image perception in the medical domain. To this end, radiologists, computed-tomography radiographers and psychology students were exposed to nine volumes of multi-slice, stack-view, axial computed-tomography images from the upper to the lower part of the abdomen with or without abnormality. The images were presented in succession at low, medium or high speed, while the participants had to detect enlarged lymph nodes or other visually more salient abnormalities. The radiologists outperformed both other groups in the detection of enlarged lymph nodes and their eye-movement behaviour also differed from the other groups. Their general strategy was to use saccades of shorter amplitude than the two other participant groups. In the presence of enlarged lymph nodes, they increased the number of fixations on the relevant areas and reverted to even shorter saccades. In volumes containing enlarged lymph nodes, radiologists' fixation durations were longer in comparison to their fixation durations in volumes without enlarged lymph nodes. More salient abnormalities were detected equally well by radiologists and radiographers, with both groups outperforming psychology students. However, to accomplish this, radiologists actually needed fewer fixations on the relevant areas than the radiographers. On the basis of these results, we argue that expert behaviour is manifested in distinct eye-movement patterns of proactivity, reactivity and suppression, depending on the nature of the task and the presence of abnormalities at any given moment.
Raymond Bertram; Johanna K Kaakinen; Frank Bensch; Laura Helle; Eila Lantto; Pekka Niemi; Nina Lundbom
In: Radiology, vol. 281, no. 3, pp. 805–815, 2016.
PURPOSE: To establish potential markers of visual expertise in eye movement (EM) patterns of early residents, advanced residents, and specialists who interpret abdominal computed tomography (CT) studies. MATERIAL AND METHODS: The institutional review board approved use of anonymized CT studies as research materials and to obtain anonymized eye-tracking data from volunteers. Participants gave written informed consent. RESULTS: Early residents (n = 15), advanced residents (n = 14), and specialists (n = 12) viewed 26 abdominal CT studies as a sequence of images at either 3 or 5 frames per second while EMs were recorded. Data were analyzed by using linear mixed-effects models. Early residents' detection rate decreased with working hours (odds ratio, 0.81; 95% confidence interval [CI]: 0.73, 0.91; P = .001). They detected less of the low visual contrast (but not of the high visual contrast) lesions (45% [13 of 29]) than did specialists (62% [18 of 29]) (odds ratio, 0.39; 95% CI: 0.25, 0.61; P , .001) or advanced residents (56% [16 of 29]) (odds ratio, 0.55; 95% CI: 0.33, 0.93; P = .024). Specialists and advanced residents had longer fixation durations at 5 than at 3 frames per second (specialists: b = .01; 95% CI: .004, .026; P = .008; advanced residents: b = .04; 95% CI: .03, .05; P , .001). In the presence of lesions, saccade lengths of specialists shortened more than those of advanced (b = .02; 95% CI: .007, .04; P = .003) and of early residents (b = .02; 95% CI: .008, 0.04; P = .003). Irrespective of expertise, high detection rate correlated with greater reduction of saccade length in the presence of lesions (b = 2.10; 95% CI: 2.16, 2.04; P = .002) and greater increase at higher presentation speed (b = .11; 95% CI: .04, .17; P = .001). CONCLUSION: Expertise in CT reading is characterized by greater adaptivity in EM patterns in response to the demands of the task and environment.
Federica Bianchi; Sébastien Santurette; Dorothea Wendt; Torsten Dau
In: JARO - Journal of the Association for Research in Otolaryngology, vol. 17, no. 1, pp. 69–79, 2016.
Musicians typically show enhanced pitch discrimination abilities compared to non-musicians. The present study investigated this perceptual enhancement behaviorally and objectively for resolved and unresolved complex tones to clarify whether the enhanced performance in musicians can be ascribed to increased peripheral frequency selectivity and/or to a different processing effort in performing the task. In a first experiment, pitch discrimination thresholds were obtained for harmonic complex tones with fundamental frequencies (F0s) between 100 and 500 Hz, filtered in either a low- or a high-frequency region, leading to variations in the resolvability of audible harmonics. The results showed that pitch discrimination performance in musicians was enhanced for resolved and unresolved complexes to a similar extent. Additionally, the harmonics became resolved at a similar F0 in musicians and non-musicians, suggesting similar peripheral frequency selectivity in the two groups of listeners. In a follow-up experiment, listeners' pupil dilations were measured as an indicator of the required effort in performing the same pitch discrimination task for conditions of varying resolvability and task difficulty. Pupillometry responses indicated a lower processing effort in the musicians versus the non-musicians, although the processing demand imposed by the pitch discrimination task was individually adjusted according to the behavioral thresholds. Overall, these findings indicate that the enhanced pitch discrimination abilities in musicians are unlikely to be related to higher peripheral frequency selectivity and may suggest an enhanced pitch representation at more central stages of the auditory system in musically trained listeners.
Nicola Binetti; Charlotte Harrison; Isabelle Mareschal; Alan Johnston
Pupil response hazard rates predict perceived gaze durations Journal Article
In: Scientific Reports, vol. 7, pp. 3969, 2017.
We investigated the mechanisms for evaluating perceived gaze-shift duration. Timing relies on the accumulation of endogenous physiological signals. Here we focused on arousal, measured through pupil dilation, as a candidate timing signal. Participants timed gaze-shifts performed by face stimuli in a Standard/Probe comparison task. Pupil responses were binned according to “Longer/Shorter” judgements in trials where Standard and Probe were identical. This ensured that pupil responses reflected endogenous arousal fluctuations opposed to differences in stimulus content. We found that pupil hazard rates predicted the classification of sub-second intervals (steeper dilation = “Longer” classifications). This shows that the accumulation of endogenous arousal signals informs gaze-shift timing judgements. We also found that participants relied exclusively on the 2nd stimulus to perform the classification, providing insights into timing strategies under conditions of maximum uncertainty. We observed no dissociation in pupil responses when timing equivalent neutral spatial displacements, indicating that a stimulus-dependent timer exploits arousal to time gaze-shifts.
Daniel Bishop; Gustav Kuhn; Claire Maton
In: Journal of Eye Movement Research, vol. 7, no. 2, pp. 1–13, 2014.
Research has shown that identifiable visual search patterns characterize skilled performance of anticipation and decision-making tasks in sport. However, to date, the use of experts' gaze patterns to entrain novices' performance has been confined to aiming activities. Accordingly, in a first experiment, 40 participants of varying soccer experience viewed static images of oncoming soccer players and attempted to predict the direction in which those players were about to move. Multiple regression analyses showed that the sole predictor of decision-making efficiency was the time taken to initiate a saccade to the ball. In a follow-up experiment, soccer novices undertook the same task as in Experiment 1. Two experimental groups were instructed to either look at the ball, or the player's head, as quickly as possible; a control group received no instructions. The experimental groups were fastest to make a saccade to the ball or head, respectively, but decision-making efficiency was equivalent across all three groups. The fallibility of a nomothetic approach to training eye movements is discussed.
Indu P Bodala; Junhua Li; Nitish V Thakor; Hasan Al-Nashash
In: Frontiers in Human Neuroscience, vol. 10, pp. 1–12, 2016.
Maintaining vigilance is possibly the first requirement for surveillance tasks where personnel are faced with monotonous yet intensive monitoring tasks. Decrement in vigilance in such situations could result in dangerous consequences such as accidents, loss of life and system failure. In this paper, we investigate the possibility to enhance vigilance or sustained attention using ‘challenge integration', a strategy that integrates a primary task with challenging stimuli. A primary surveillance task (identifying an intruder in a simulated factory environment) and a challenge stimulus (periods of rain obscuring the surveillance scene) were employed to test the changes in vigilance levels. The effect of integrating challenging events (resulting from artificially simulated rain) into the task were compared to the initial monotonous phase. EEG and eye tracking data is collected and analyzed for n = 12 subjects. Frontal midline theta power and frontal theta to parietal alpha power ratio which are used as measures of engagement and attention allocation show an increase due to challenge integration (p textless 0.05 in each case). Relative delta band power of EEG also shows statistically significant suppression on the frontoparietal and occipital cortices due to challenge integration (p textless 0.05). Saccade amplitude, saccade velocity and blink rate obtained from eye tracking data exhibit statistically significant changes during the challenge phase of the experiment (p textless 0.05 in each case). From the correlation analysis between the statistically significant measures of eye tracking and EEG, we infer that saccade amplitude and saccade velocity decrease with vigilance decrement along with frontal midline theta and frontal theta to parietal alpha ratio. Conversely, blink rate and relative delta power increase with vigilance decrement. However, these measures exhibit a reverse trend when challenge stimulus appears in the task suggesting vigilance enhancement. Moreover, the mean reaction time is lower for the challenge integrated phase (RT mean = 3.65 ± 1.4 secs) compared to initial monotonous phase without challenge (RT mean = 4.6 ± 2.7 secs). Our work shows that vigilance level, as assessed by response of these vital signs, is enhanced by challenge integration.
Anissa Boutabla; Samuel Cavuscens; Maurizio Ranieri; Céline Crétallaz; Herman Kingma; Raymond van de Berg; Nils Guinand; Angélica Pérez Fornos
In: Journal of Neurology, vol. 267, no. 1, pp. S273–S284, 2020.
Background and purpose: Vestibular implants seem to be a promising treatment for patients suffering from severe bilateral vestibulopathy. To optimize outcomes, we need to investigate how, and to which extent, the different vestibular pathways are activated. Here we characterized the simultaneous responses to electrical stimuli of three different vestibular pathways. Methods: Three vestibular implant recipients were included. First, activation thresholds and amplitude growth functions of electrically evoked vestibulo-ocular reflexes (eVOR), cervical myogenic potentials (ecVEMPs) and vestibular percepts (vestibulo-thalamo-cortical, VTC) were recorded upon stimulation with single, biphasic current pulses (200 µs/phase) delivered through five different vestibular electrodes. Latencies of eVOR and ecVEMPs were also characterized. Then we compared the amplitude growth functions of the three pathways using different stimulation profiles (1-pulse, 200 µs/phase; 1-pulse, 50 µs/phase; 4-pulses, 50 µs/phase, 1600 pulses-per-second) in one patient (two electrodes). Results: The median latencies of the eVOR and ecVEMPs were 8 ms (8–9 ms) and 10.2 ms (9.6–11.8 ms), respectively. While the amplitude of eVOR and ecVEMP responses increased with increasing stimulation current, the VTC pathway showed a different, step-like behavior. In this study, the 200 µs/phase paradigm appeared to give the best balance to enhance responses at lower stimulation currents. Conclusions: This study is a first attempt to evaluate the simultaneous activation of different vestibular pathways. However, this issue deserves further and more detailed investigation to determine the actual possibility of selective stimulation of a given pathway, as well as the functional impact of the contribution of each pathway to the overall rehabilitation process.
Hanneke Bouwsema; Corry K van der Sluis; Raoul M Bongers
In: Journal of NeuroEngineering and Rehabilitation, vol. 11, no. 1, pp. 1–15, 2014.
BACKGROUND: Training increases the functional use of an upper limb prosthesis, but little is known about how people learn to use their prosthesis. The aim of this study was to describe the changes in performance with an upper limb myoelectric prosthesis during practice. The results provide a basis to develop an evidence-based training program. METHODS: Thirty-one able-bodied participants took part in an experiment as well as thirty-one age- and gender-matched controls. Participants in the experimental condition, randomly assigned to one of four groups, practiced with a myoelectric simulator for five sessions in a two-weeks period. Group 1 practiced direct grasping, Group 2 practiced indirect grasping, Group 3 practiced fixating, and Group 4 practiced a combination of all three tasks. The Southampton Hand Assessment Procedure (SHAP) was assessed in a pretest, posttest, and two retention tests. Participants in the control condition performed SHAP two times, two weeks apart with no practice in between. Compressible objects were used in the grasping tasks. Changes in end-point kinematics, joint angles, and grip force control, the latter measured by magnitude of object compression, were examined. RESULTS: The experimental groups improved more on SHAP than the control group. Interestingly, the fixation group improved comparable to the other training groups on the SHAP. Improvement in global position of the prosthesis leveled off after three practice sessions, whereas learning to control grip force required more time. The indirect grasping group had the smallest object compression in the beginning and this did not change over time, whereas the direct grasping and the combination group had a decrease in compression over time. Moreover, the indirect grasping group had the smallest grasping time that did not vary over object rigidity, while for the other two groups the grasping time decreased with an increase in object rigidity. CONCLUSIONS: A training program should spend more time on learning fine control aspects of the prosthetic hand during rehabilitation. Moreover, training should start with the indirect grasping task that has the best performance, which is probably due to the higher amount of useful information available from the sound hand.
Jan W Brascamp; Marnix Naber
In: Behavior Research Methods, vol. 49, no. 4, pp. 1303–1309, 2017.
In several research contexts it is important to obtain eye-tracking measures while presenting visual stimuli inde- pendently to each of the two eyes (dichoptic stimulation). However, the hardware that allows dichoptic viewing, such as mirrors, often interferes with high-quality eye tracking, es- pecially when using a video-based eye tracker. Here we detail an approach to combining mirror-based dichoptic stimulation with video-based eye tracking, centered on the fact that some mirrors, although they reflect visible light, are selectively transparent to the infrared wavelength range in which eye trackers record their signal. Although the method we propose is straightforward, affordable (on the order ofUS$1,000) and easy to implement, for many purposes it makes for an im- provement over existing methods, which tend to require spe- cialized equipment and often compromise on the quality ofthe visual stimulus and/or the eye tracking signal. The proposed method is compatible with standard display screens and eye trackers, and poses no additional limitations on the quality or nature of the stimulus presented or the data obtained. We in- clude an evaluation ofthe quality ofeye tracking data obtained using our method, and a practical guide to building a specific version of the setup used in our laboratories.
Hanna Brinkmann; Louis Williams; Raphael Rosenberg; Eugene McSorley
In: Art and Perception, vol. 8, no. 1, pp. 27–48, 2020.
Throughout the 20th century, there have been many different forms of abstract painting. While works by some artists, e.g., Piet Mondrian, are usually described as static, others are described as dynamic, such as Jackson Pollock's 'action paintings'. Art historians have assumed that beholders not only conceptualise such differences in depicted dynamics but also mirror these in their viewing behaviour. In an interdisciplinary eye-tracking study, we tested this concept through investigating both the localisation of fixations (polyfocal viewing) and the average duration of fixations as well as saccade velocity, duration and path curvature. We showed 30 different abstract paintings to 40 participants - 20 laypeople and 20 experts (art students) - and used self-reporting to investigate the perceived dynamism of each painting and its relationship with (a) the average number and duration of fixations, (b) the average number, duration and velocity of saccades as well as the amplitude and curvature area of saccade paths, and (c) pleasantness and familiarity ratings. We found that the average number of fixations and saccades, saccade velocity, and pleasantness ratings increase with an increase in perceived dynamism ratings. Meanwhile the saccade duration decreased with an increase in perceived dynamism. Additionally, the analysis showed that experts gave higher dynamic ratings compared to laypeople and were more familiar with the artworks. These results indicate that there is a correlation between perceived dynamism in abstract painting and viewing behaviour - something that has long been assumed by art historians but had never been empirically supported.
Tom Bullock; James C Elliott; John T Serences; Barry Giesbrecht
In: Journal of Cognitive Neuroscience, vol. 29, no. 4, pp. 605–618, 2016.
An organism's current behavioral state influences ongoing brain activity. Nonhuman mammalian and invertebrate brains exhibit large increases in the gain of feature-selective neural responses in sensory cortex during locomotion, suggesting that the visual system becomes more sensitive when actively exploring the environment. This raises the possibility that human vision is also more sensitive during active movement. To investigate this possibility, we used an inverted encoding model technique to estimate feature-selective neural response profiles from EEG data acquired from participants performing an orientation discrimination task. Participants (n = 18) fixated at the center of a flickering (15 Hz) circular grating presented at one of nine different orientations and monitored for a brief shift in orientation that occurred on every trial. Participants completed the task while seated on a stationary exercise bike at rest and during low- and high-intensity cycling. We found evidence for inverted-U effects; such that the peak of the reconstructed feature-selective tuning profiles was highest during low-intensity exercise compared with those estimated during rest and high-intensity exercise. When modeled, these effects were driven by changes in the gain of the tuning curve and in the profile bandwidth during low-intensity exercise relative to rest. Thus, despite profound differences in visual pathways across species, these data show that sensitivity in human visual cortex is also enhanced during locomotive behavior. Our results reveal the nature of exercise-induced gain on feature-selective coding in human sensory cortex and provide valuable evidence linking the neural mechanisms of behavior state across species.
Christopher D D Cabrall; Riender Happee; Joost C F De Winter
In: Transportation Research Part F: Traffic Psychology and Behaviour, vol. 68, pp. 187–197, 2020.
For transitions of control in automated vehicles, driver monitoring systems (DMS) may need to discern task difficulty and driver preparedness. Such DMS require models that relate driving scene components, driver effort, and eye measurements. Across two sessions, 15 participants enacted receiving control within 60 randomly ordered dashcam videos (3-second duration) with variations in visible scene components: road curve angle, road surface area, road users, symbols, infrastructure, and vegetation/trees while their eyes were measured for pupil diameter, fixation duration, and saccade amplitude. The subjective measure of effort and the objective measure of saccade amplitude evidenced the highest correlations (r = 0.34 and r = 0.42, respectively) with the scene component of road curve angle. In person-specific regression analyses combining all visual scene components as predictors, average predictive correlations ranged between 0.49 and 0.58 for subjective effort and between 0.36 and 0.49 for saccade amplitude, depending on cross-validation techniques of generalization and repetition. In conclusion, the present regression equations establish quantifiable relations between visible driving scene components with both subjective effort and objective eye movement measures. In future DMS, such knowledge can help inform road-facing and driver-facing cameras to jointly establish the readiness of would-be drivers ahead of receiving control.
Aurélie Calabrèse; Carlos Aguilar; Géraldine Faure; Frédéric Matonti; Louis Hoffart; Eric Castet
In: Optometry and Vision Science, vol. 95, no. 9, pp. 738–746, 2018.
SIGNIFICANCE: The overall goal of this work is to validate a low vision aid system that uses gaze as a pointing tool and provides smart magnification. We conclude that smart visual enhancement techniques as well as gaze contingency should improve the efficiency of assistive technology for the visually impaired. PURPOSE: A low vision aid, using gaze-contingent visual enhancement and primarily intended to help reading with central vision loss, was recently designed and tested with simulated scotoma. Here, we present a validation of this system for face recognition in age-related macular degeneration patients. METHODS: Twelve individuals with binocular central vision loss were recruited and tested on a face identification-matching task. Gaze position was measured in real time, thanks to an eye tracker. In the visual enhancement condition, at any time during the screen exploration, the fixated face was segregated from background and considered as a region of interest that could be magnified into a region of augmented vision by the participant, if desired. In the natural exploration condition, participants also performed the matching task but without the visual aid. Response time and accuracy were analyzed with mixed-effects models to (1) compare the performance with and without visual aid and (2) estimate the usability of the system. RESULTS: On average, the percentage of correct response for the natural exploration condition was 41%. This value was significantly increased to 63% with visual enhancement (95% confidence interval, 45 to 78%). For the large majority of our participants (83%), this improvement was accompanied by moderate increase in response time, suggesting a real functional benefit for these individuals. CONCLUSIONS Without visual enhancement, participants with age-related macular degeneration performed poorly, confirming their struggle for face recognition and the need to use efficient visual aids. Our system significantly improved face identification accuracy by 55%, proving to be helpful under laboratory conditions.
Rouwen Cañal-Bruland; Simone Lotz; Norbert Hagemann; Jörg Schorer; Bernd Strauss
Visual span and change detection in soccer: An expertise study Journal Article
In: Journal of Cognitive Psychology, vol. 23, no. 3, pp. 302–310, 2011.
There is evidence to suggest that sports experts are able to extract more perceptual information from a single fixation than novices when exposed to meaningful tasks that are specific to their field of expertise. In particular, Reingold et al. (2001) showed that chess experts use a larger visual span including fewer fixations when compared to their less skilled counterparts. The aim of the present study was to examine whether also in a more complex environment, namely soccer, skilled players use a larger visual span and fewer fixations than less skilled players when attempting to recognise players' positions. To this end, we combined the gaze-contingent window technique with the change detection paradigm. Results seem to suggest that skilled soccer players do not use a larger visual span than less skilled players. However, skilled soccer players showed significantly fewer fixations of longer duration than their less skilled counterparts, supporting the notion that experts may extract more information from a single glance.
Matt Canham; Mary Hegarty
In: Learning and Instruction, vol. 20, no. 2, pp. 155–166, 2010.
In two experiments, participants made inferences from weather maps, before and after they received instruction about relevant meteorological principles. Different versions of the maps showed either task-relevant information alone, or both task-relevant and task-irrelevant information. Participants improved on the inference task after instruction, indicating that they could apply newly acquired declarative knowledge to make inferences from graphics. In Experiment 1, participants spent more time viewing task-relevant information and less time viewing task-irrelevant information after instruction, and in Experiment 2, the presence of task-irrelevant information impaired performance. These results show that domain knowledge can affect information selection and encoding from complex graphics as well as processes of interpreting and making inferences from the encoded information. They also provide validation of one principle for the design of effective graphical displays, namely that graphics should not display more information than is required for the task at hand.
Andrea Caoli; Silvio P Sabatini; Agostino Gibaldi; Guido Maiello; Anna Kosovicheva; Peter Bex
In: Scientific Reports, vol. 10, pp. 1–13, 2020.
Strabismus is a prevalent impairment of binocular alignment that is associated with a spectrum of perceptual deficits and social disadvantages. Current treatments for strabismus involve ocular alignment through surgical or optical methods and may include vision therapy exercises. In the present study, we explore the potential of real-time dichoptic visual feedback that may be used to quantify and manipulate interocular alignment. A gaze-contingent ring was presented independently to each eye of 11 normally-sighted observers as they fixated a target dot presented only to their dominant eye. Their task was to center the rings within 2° of the target for at least 1 s, with feedback provided by the sizes of the rings. By offsetting the ring in the non-dominant eye temporally or nasally, this task required convergence or divergence, respectively, of the non-dominant eye. Eight of 11 observers attained 5° asymmetric convergence and 3 of 11 attained 3° asymmetric divergence. The results suggest that real-time gaze-contingent feedback may be used to quantify and transiently simulate strabismus and holds promise as a method to augment existing therapies for oculomotor alignment disorders.
Etzel Cardeña; Barbara Nordhjem; David Marcusson-Clavertz; Kenneth Holmqvist
In: PLoS ONE, vol. 12, no. 8, pp. e0182546, 2017.
Responsiveness to hypnotic procedures has been related to unusual eye behaviors for centuries. Kallio and collaborators claimed recently that they had found a reliable index for "the hypnotic state" through eye-tracking methods. Whether or not hypnotic responding involves a special state of consciousness has been part of a contentious debate in the field, so the potential validity of their claim would constitute a landmark. However, their conclusion was based on 1 highly hypnotizable individual compared with 14 controls who were not measured on hypnotizability. We sought t o replicate their results with a sample screened for High (n = 16) or Low (n = 13) hypnotizability. We used a factorial 2 (high vs. low hypnotizability) x 2 (hypnosis vs. resting conditions) counterbalanced order design with these eye-tracking tasks: Fixation, Saccade, Optokinetic nystagmus (OKN), Smooth pursuit, and Antisaccade (the first three tasks has been used in Kallio et al.'s experiment). Highs reported being more deeply in hypnosis than Lows but only in the hypnotic condition, as expected. There were no significant main or interaction effects for the Fixation, OKN, or Smooth pursuit tasks. For the Saccade task both Highs and Lows had smaller saccades during hypnosis, and in the Antisaccade task both groups had slower Antisaccades during hypnosis. Although a couple of results suggest that a hypnotic condition may produce reduced eye motility, the lack of significant interactions (e.g., showing only Highs expressing a particular eye behavior during hypnosis) does not support the claim that eye behaviors (at least as measured with the techniques used) are an indicator of a "hypnotic state.” Our results do not preclude the possibility that in a more spontaneous or different setting the experience of being hypnotized might relate to specific eye behaviors.
Jean Carletta; Robin L Hill; Craig Nicol; Tim Taylor; Jan Peter de Ruiter; Ellen Gurman Bard
In: Behavior Research Methods, vol. 42, no. 1, pp. 254–265, 2010.
Eyetracking facilities are typically restricted to monitoring a single person viewing static images or pre-recorded video. In the present article, we describe a system that makes it possible to study visual attention in coordination with other activity during joint action. The software links two eyetracking systems in parallel and provides an on-screen task. By locating eye movements against dynamic screen regions, it permits automatic tracking of moving on-screen objects. Using existing SR technology, the system can also cross-project each participant's eyetrack and mouse location onto the other's on-screen work space. Keeping a complete record of eyetrack and on-screen events in the same format as subsequent human coding, the system permits the analysis of multiple modalities. The software offers new approaches to spontaneous multimodal communication: joint action and joint attention. These capacities are demonstrated using an experimental paradigm for cooperative on-screen assembly of a two-dimensional model. The software is available under an open source license.
Matthew R Cavanaugh; Lisa M Blanchard; Michael McDermott; Byron L Lam; Madhura Tamhankar; Steven E Feldon
In: Ophthalmology, pp. 1–11, 2020.
Purpose: To evaluate the efficacy of motion discrimination training as a potential therapy for stroke-induced hemianopic visual field defects. Design: Clinical trial. Participants: Forty-eight patients with stroke-induced homonymous hemianopia (HH) were randomized into 2 training arms: intervention and control. Patients were between 21 and 75 years of age and showed no ocular issues at presentation. Methods: Patients were trained on a motion discrimination task previously evidenced to reduce visual field deficits, but not in a randomized clinical trial. Patients were randomized with equal allocation to receive training in either their sighted or deficit visual fields. Training was performed at home for 6 months, consisting of repeated visual discriminations at a single location for 20 to 30 minutes daily. Study staff and patients were masked to training type. Testing before and after training was identical, consisting of Humphrey visual fields (Carl Zeiss Meditech), macular integrity assessment perimetry, OCT, motion discrimination performance, and visual quality- of-life questionnaires. Main Outcome Measures: Primary outcome measures were changes in perimetric mean deviation (PMD) on Humphrey Visual Field Analyzer in both eyes. Results: Mean PMDs improved over 6 months in deficit-trained patients (mean change in the right eye, 0.58 dB; 95% confidence interval, 0.07e1.08 dB; mean change in the left eye 0.84 dB; 95% confidence interval, 0.22e1.47 dB). No improvement was observed in sighted-trained patients (mean change in the right eye, 0.12 dB; 95% confidence interval, e0.38 to 0.62 dB; mean change in the left eye, 0.10 dB; 95% confidence interval, e0.52 to 0.72 dB). However, no significant differences were found between the alternative training methods (right eye
Benedetta Cesqui; Maura Mezzetti; Francesco Lacquaniti; Andrea D'Avella
In: PLoS ONE, vol. 10, no. 3, pp. e0119445, 2015.
In ball sports, it is usually acknowledged that expert athletes track the ball more accurately than novices. However, there is also evidence that keeping the eyes on the ball is not always necessary for interception. Here we aimed at gaining new insights on the extent to which ocular pursuit performance is related to catching performance. To this end, we analyzed eye and head movements of nine subjects catching a ball projected by an actuated launching apparatus. Four different ball flight durations and two different ball arrival heights were tested and the quality of ocular pursuit was characterized by means of several timing and accuracy parameters. Catching performance differed across subjects and depended on ball flight characteristics. All subjects showed a similar sequence of eye movement events and a similar modulation of the timing of these events in relation to the characteristics of the ball trajectory. On a trial-by-trial basis there was a significant relationship only between pursuit duration and catching performance, confirming that keeping the eyes on the ball longer increases catching success probability. Ocular pursuit parameters values and their dependence on flight conditions as well as the eye and head contributions to gaze shift differed across subjects. However, the observed average individual ocular behavior and the eye-head coordination patterns were not directly related to the individual catching performance. These results suggest that several oculomotor strategies may be used to gather information on ball motion, and that factors unrelated to eye movements may underlie the observed differences in interceptive performance.
Myriam Chanceaux; Anne Guérin-Dugué; Benoît Lemaire; Thierry Baccino
In: Cognitive Computation, vol. 6, no. 1, pp. 1–17, 2014.
Document foraging for information is a crucial and increasingly prevalent activity nowadays. We designed a computational cognitive model to simulate the oculomotor scanpath of an average web user searching for specific information from textual materials. In particular, the developed model dynamically combines visual, semantic, and memory processes to predict the user's focus of attention during information seeking from paragraphs of text. A series of psychological experiments was conducted using eye-tracking techniques in order to validate and refine the proposed model. Comparisons between model simulations and human data are reported and discussed taking into account the strengths and shortcomings of the model. The proposed model provides a unique contribution to the investigation of the cognitive processes involved during information search and bears significant implications for web page design and evaluation.
Samuel G Charlton; Nicola J Starkey; John A Perrone; Robert B Isler
In: Transportation Research Part F: Traffic Psychology and Behaviour, vol. 25, no. A, pp. 50–64, 2014.
It has long been presumed that drivers' perceptions of risk play an important role in guiding on-road behaviour. The answer to how accurately drivers perceive the momentary risk of a driving situation, however, is unknown. This research compared drivers' perceptions of the momentary risk for a range of roads to the objective risk associated with those roads. Videos of rural roads, filmed from the drivers' perspective, were presented to 69 participants seated in a driving simulator while they indicated the momentary levels of risk they were experiencing by moving a risk meter mounted on the steering wheel. Estimates of the objective levels of risk for the roads were calculated using road protection scores from the KiwiRAP database (part of the International Road Assessment Programme). Subsequently, the participants also provided risk estimates for still photos taken from the videos. Another group of 10 participants viewed the videos and photos while their eye movements and fixations were recorded. In a third experiment, 14 participants drove a subset of the roads in a car while providing risk ratings at selected points of interest. Results showed a high degree of consistency across the different methods. Certain road situations were rated as being riskier than the objective risk, and perhaps more importantly, the risk of other situations was significantly under-rated. Horizontal curves and narrow lanes were associated with over-rated risk estimates, while intersections and roadside hazards such as narrow road shoulders, power poles and ditches were significantly under-rated. Analysis of eye movements indicated that drivers did not fixate these features and that the spread of fixations, pupil size and eye blinks were significantly correlated with the risk ratings. An analysis of the road design elements at 77 locations in the video revealed five road characteristics that predicted nearly 80% of the variance in drivers' risk perceptions; horizontal curvature, lane and shoulder width, gradient, and the presence of median barriers.
Wenxiang Chen; Xiangling Zhuang; Zixin Cui; Guojie Ma
In: Transportation Research Part F: Traffic Psychology and Behaviour, vol. 64, pp. 552–564, 2019.
Drivers' recognition of pedestrian road crossing intentions is an essential process during driver-pedestrian interaction. However, compared with the rich observational findings on interaction behavior, little is known on drivers' performance in recognizing pedestrian intentions, as well as the underlying cognitive processes. To fill in the gap, this study evaluated drivers' performance in making judgments of pedestrians' road crossing intentions in recorded natural driving scenes. Experienced and novice drivers identified pedestrians as “will cross” or “will not cross” at some time-to-arrival while their eye movements were recorded. The results showed that experienced drivers were more conservative in discriminating whether a pedestrian would cross or not (preferred a “pedestrian will cross” judgment) and took a higher level of information processing of pedestrian intention. Regardless of driving experience, drivers had a higher detection rate, earlier detection, higher level of information processing and quicker response over pedestrians who intended to cross than those did not intend to cross. A quicker response was also achieved when the time-to-arrival was smaller. Analysis of eye movements showed attentional bias to the upper body of pedestrians when recognizing intention. These findings offer an initial understanding of the intention recognition process during driver-pedestrian interaction and inform directions for autonomous driving research when interacting with pedestrians.
Xianglan Chen; Hulin Ren; Yamin Liu; Bendegul Okumus; Anil Bilgihan
In: International Journal of Hospitality Management, vol. 84, pp. 1–10, 2020.
Food is as cultural as it is practical, and names of dishes accordingly have cultural nuances. Menus serve as communication tools between restaurants and their guests, representing the culinary philosophy of the chefs and proprietors involved. The purpose of this experimental lab study is to compare differences of attention paid to textual and pictorial elements of menus with metaphorical and/or metonymic names. Eye movement technology was applied in a 2 × 3 between-subject experiment (n = 40), comparing the strength of visual metaphors (e.g., images of menu items on the menu) and direct textual names in Chinese and English with regard to guests' willingness to purchase the dishes in question. Post-test questionnaires were also employed to assess participants' attitudes toward menu designs. Study results suggest that visual metaphors are more efficient when reflecting a product's strength. Images are shown to positively influence consumers' expectations of taste and enjoyment, garnering the most attention under all six conditions studied here, and constitute the most effective format when Chinese alone names are present. The textual claim increases perception of the strength of menu items along with purchase intention. Metaphorical dish names with bilingual (i.e., Chinese and English) names hold the greatest appeal. This result can be interpreted from the perspective of grounded cognition theory, which suggests that situated simulations and re-enactment of perceptual, motor, and affective processes can support abstract thought. The lab results and survey provide specific theoretical and managerial implications with regard to translating names of Chinese dishes to attract customers' attention to specific menu items.
Agnieszka Chmiel; Przemysław Janikowski; Agnieszka Lijewska
Multimodal processing in simultaneous interpreting with text Journal Article
In: Target, vol. 32, no. 1, pp. 37–58, 2020.
The present study focuses on (in)congruence of input between the visual and the auditory modality in simultaneous interpreting with text. We asked twenty-four professional conference interpreters to simultaneously interpret an aurally and visually presented text with controlled incongruences in three categories (numbers, names and control words), while measuring interpreting accuracy and eye movements. The results provide evidence for the dominance of the visual modality, which goes against the professional standard of following the auditory modality in the case of incongruence. Numbers enjoyed the greatest accuracy across conditions possibly due to simple cross-language semantic mappings. We found no evidence for a facilitation effect for congruent items, and identified an impeding effect of the presence of the visual text for incongruent items. These results might be interpreted either as evidence for the Colavita effect (in which visual stimuli take precedence over auditory ones) or as strategic behaviour applied by professional interpreters to avoid risk.
Mina Choi; Joel Wang; Wei Chung Cheng; Giovanni Ramponi; Luigi Albani; Aldo Badano
In: IEEE/OSA Journal of Display Technology, vol. 10, no. 5, pp. 420–428, 2014.
We describe a methodology for predicting the detectability of subtle targets in dark regions of high-dynamic-range (HDR) images in the presence of veiling glare in the human eye. The method relies on predictions of contrast detection thresholds for the human visual system within a HDR image based on psychophysics measurements and modeling of the HDR display device characteristics. We present experimental results used to construct the model and discuss an image-dependent empirical veiling glare model and the validation of the model predictions with test patterns, natural scenes, and medical images. The model predictions are compared to a previously reported model (HDR-VDP2) for predicting HDR image quality accounting for glare effects. textcopyright 2005-2012 IEEE.
Rajib Chowdhury; A F M Saifuddin Saif
In: International Journal of Software Engineering and Computer Systems, vol. 53, no. 1, pp. 52–56, 2019.
The main purpose of this research is to investigate the human brain sensor activities related prior researches towards the needs of an efficient method to improve the human brain sensor activities. Human brain activities mainly measured by brain signal acquired from the brain sensor electrodes positioned on several parts of the brain cortex. Although previous researches investigated human brain activities in various aspects, the improvement of the human brain sensor activities is still unsolved. In today's world, it is very crucial need for improving the sensor activities of the human brain using that human brain improved signal externally. This research demonstrated a comprehensive critical analysis of human brain activities related prior researches to claim for an efficient method integrated with proposed neuroheadset device. This research presented a comprehensive review in various aspects like previous methods, existing frameworks analysis and existing results analysis with the discussion to establish an efficient method for acquiring human brain signal, improving the acquired signal and developing the sensor activities of the human brain using that human brain improved signal. Demonstrated critical review has expected for constituting an efficient method to improve the performance of maneuverability, visualization, subliminal activities and so forth on human brain activities.
Sauman Chu; Nora Paul; Laura Ruel
In: Information Design Journal, vol. 17, no. 1, pp. 31–43, 2009.
Online environments allow for a richer expression for certain design elements. The goal of this collaborative research project is to identify, design, and examine various online news features in order to determine the impact of different digital design combinations on news audiences. Eye tracking was the primary method we used to examine three main areas: navigation for slide shows, effectiveness of breaking news formats, and design options for supplemental links. The project used an applied research approach by taking academically rigorous research and using that to inform and guide industry practice. [ABSTRACT FROM AUTHOR] Copyright of Information Design Journal (IDJ) is the property of John Benjamins Publishing Co. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.
Tanja R M Coeckelbergh
The effect of visual field defects on driving performance Journal Article
In: Archives of Ophthalmology, vol. 120, no. 11, pp. 1509–1516, 2002.
Objectives: To investigate the effect of visual field de-fects on driving performance, and to predict practical fit-ness to drive. Methods: The driving performance of 87 subjects with visual field defects due to ocular abnormalities was as-sessed on a driving simulator and during an on-road driv-ing test. Outcome Measures: The final score on the on-road driving test and simulator indexes, such as driving speed, viewing behavior, lateral position, time-headway, and time to collision. Results: Subjects with visual field defects showed dif-ferential performance on measures of driving speed, steer-ing stability, lateral position, time to collision, and time-headway. Effective compensation consisted of reduced driving speed in cases of central visual field defects and increased scanning in cases of peripheral visual field de-fects. The sensitivity and specificity of models based on vision, visual attention, and compensatory viewing effi-ciency were increased when the distance at which the sub-ject started to scan was taken into account. Conclusions: Subjects with visual field defects demon-strated differential performance on several driving simu-lator indexes. Driving examiners considered reduced speed and increased scanning to be valid compensation for cen-tral and peripheral visual field defects, respectively. Pre-dicting practical fitness to drive was improved by taking driving simulator indexes into account.
Tanja R M Coeckelbergh; Frans W Cornelissen; Wiebo H Brouwer; Aart C Kooijman
In: Vision Research, vol. 42, no. 5, pp. 669–677, 2002.
Eye movements of subjects with visual field defects due to ocular pathology were monitored while performing a dot counting task and a visual search task. Subjects with peripheral field defects required more fixations, longer search times, made more errors, and had shorter fixation durations than control subjects. Subjects with central field defects performed less well than control subjects although no specific impairment could be pinpointed. In both groups a monotonous relationship was observed between the visual field impairment and eye movement parameters. The use of eye movement parameters to predict viewing behavior in a complex task (e.g. driving) was limited.
Martin C Cölln; Kerstin Kusch; Jens R Helmert; Petra Kohler; Boris M Velichkovsky; Sebastian Pannasch
In: Applied Ergonomics, vol. 43, no. 1, pp. 48–56, 2012.
Francisco M Costela; José J Castro-Torres
In: Transportation Research Part F: Traffic Psychology and Behaviour, vol. 74, pp. 511–521, 2020.
Background: Many studies have found that eye movement behavior provides a real-time index of mental activity. Risk management architectures embedded in autonomous vehicles fail to include human cognitive aspects. We set out to evaluate whether eye movements during a risk driving detection task are able to predict risk situations. Methods: Thirty-two normally sighted subjects (15 female) saw 20 clips of recorded driving scenes while their gaze was tracked. They reported when they considered the car should brake, anticipating any hazard. We applied both a mixed-effect logistic regression model and feedforward neural networks between hazard reports and eye movement descriptors. Results: All subjects reported at least one major collision hazard in each video (average 3.5 reports). We found that hazard situations were predicted by larger saccades, more and longer fixations, fewer blinks, and a smaller gaze dispersion in both horizontal and vertical dimensions. Performance between models incorporating a different combination of descriptors was compared running a test equality of receiver operating characteristic areas. Feedforward neural networks outperformed logistic regressions in accuracies. The model including saccadic magnitude, fixation duration, dispersion in ×, and pupil returned the highest ROC area (0.73). Conclusion: We evaluated each eye movement descriptor successfully and created separate models that predicted hazard events with an average efficacy of 70% using both logistic regressions and feedforward neural networks. The use of driving simulators and hazard detection videos can be considered a reliable methodology to study risk prediction.
Antoine Coutrot; Nathalie Guyader; Gelu Ionescu; Alice Caplier
In: Annals of Telecommunications, vol. 69, no. 1-2, pp. 89–97, 2014.
We assess whether salient auditory events contained in soundtracks modify eye movements when exploring videos. In a previous study, we found that, on average, nonspatial sound contained in video soundtracks impacts on eye movements. This result indicates that sound could play a leading part in visual attention models to predict eye movements. In this research, we go further and test whether the effect of sound on eye movements is stronger just after salient auditory events. To automatically spot salient auditory events, we used two auditory saliency models: the discrete energy separation algorithm and the energy model. Both models provide a saliency time curve, based on the fusion of several elementary audio features. The most salient auditory events were extracted by thresholding these curves. We examined some eye movement parameters just after these events rather than on all the video frames. We showed that the effect of sound on eye movements (variability between eye positions, saccade amplitude, and fixation duration) was not stronger after salient auditory events than on average over entire videos. Thus, we suggest that sound could impact on visual exploration not only after salient events but in a more global way. textcopyright 2013 Institut Mines-Télécom and Springer-Verlag France.
David P Crabb; Nicholas D Smith; Franziska G Rauscher; Catharine M Chisholm; John L Barbur; David F Edgar; David F Garway-Heath
In: PLoS ONE, vol. 5, no. 3, pp. e9710, 2010.
BACKGROUND: Glaucoma is a progressive eye disease and a leading cause of visual disability. Automated assessment of the visual field determines the different stages in the disease process: it would be desirable to link these measurements taken in the clinic with patient's actual function, or establish if patients compensate for their restricted field of view when performing everyday tasks. Hence, this study investigated eye movements in glaucomatous patients when viewing driving scenes in a hazard perception test (HPT). METHODOLOGY/PRINCIPAL FINDINGS: The HPT is a component of the UK driving licence test consisting of a series of short film clips of various traffic scenes viewed from the driver's perspective each containing hazardous situations that require the camera car to change direction or slow down. Data from nine glaucomatous patients with binocular visual field defects and ten age-matched control subjects were considered (all experienced drivers). Each subject viewed 26 different films with eye movements simultaneously monitored by an eye tracker. Computer software was purpose written to pre-process the data, co-register it to the film clips and to quantify eye movements and point-of-regard (using a dynamic bivariate contour ellipse analysis). On average, and across all HPT films, patients exhibited different eye movement characteristics to controls making, for example, significantly more saccades (Ptextless0.001; 95% confidence interval for mean increase: 9.2 to 22.4%). Whilst the average region of 'point-of-regard' of the patients did not differ significantly from the controls, there were revealing cases where patients failed to see a hazard in relation to their binocular visual field defect. CONCLUSIONS/SIGNIFICANCE: Characteristics of eye movement patterns in patients with bilateral glaucoma can differ significantly from age-matched controls when viewing a traffic scene. Further studies of eye movements made by glaucomatous patients could provide useful information about the definition of the visual field component required for fitness to drive.
Freya Crosby; Frouke Hermens
In: Quarterly Journal of Experimental Psychology, vol. 72, no. 3, pp. 599–615, 2019.
Studies of fear of crime often focus on demographic and social factors, but these can be difficult to change. Studies of visual aspects have suggested that features reflecting incivilities, such as litter, graffiti, and vandalism increase fear of crime, but methods often rely on participants actively mentioning such aspects, and more subtle, less conscious aspects may be overlooked. To address these concerns, this study examined people's eye movements while they judged scenes for safety. In total, 40 current and former university students were asked to rate images of day-time and night-time scenes of Lincoln, UK (where they studied) and Egham, UK (unfamiliar location) for safety, maintenance, and familiarity while their eye movements were recorded. Another 25 observers not from Lincoln or Egham rated the same images in an Internet survey. Ratings showed a strong association between safety and maintenance and lower safety ratings for night-time scenes for both groups, in agreement with earlier findings. Eye movements of the Lincoln participants showed increased dwell times on buildings, houses, and vehicles during safety judgements and increased dwell times on streets, pavements, and markers of incivilities for maintenance. Results confirm that maintenance plays an important role in perceptions of safety, but eye movements suggest that observers also look for indicators of current or recent presence of people.
David Crundall; Peter Chapman; Nicola Phelps; Geoffrey Underwood
In: Journal of Experimental Psychology: Applied, vol. 9, no. 3, pp. 163–174, 2003.
How do police cope with the visual demands placed on them during pursuit driving? This study compared the hazard ratings, eye movements, and physiological responses of police drivers with novice and with age-matched control drivers while viewing video clips of driving taken from police vehicles. The clips included pursuits, emergency responses, and control drives. Although police drivers did not report more hazards than the other participants reported, they had an increased frequency of electrodermal responses while viewing dangerous clips and a greater visual sampling rate and spread of search. However, despite an overall police advantage in oculomotor and physiological measures, all drivers had a reduced spread of search in nighttime pursuits because of the focusing of overt attention.
David Crundall; Claire Shenton; Geoffrey Underwood
Eye movements during intentional car following Journal Article
In: Perception, vol. 33, no. 8, pp. 975–986, 2004.
Does intentional car following capture visual attention to the extent that driving may be impaired? We tested fifteen participants on a rudimentary driving simulator. Participants were either instructed to follow a vehicle ahead through a simulated version of London, or were given verbal instructions on where to turn during the route. The presence or absence of pedestrians, and the simulated time of the drive (day or night) were varied across the trials. Eye movements were recorded along with behavioural measures including give-way violations, give-way accidents, and kerb impacts. The results revealed that intentional car following reduced the spread of search and increased fixation durations, with a dramatic increase in the time spent processing the vehicle ahead (controlled for exposure). The effects were most pronounced during nighttime drives. During the car-following trials participants were also less aware of pedestrians, produced more give-way violations, and were involved in more give-way accidents. The results draw attention to the problems encountered during car following, and we relate this to the cognitive demands placed on drivers, especially police drivers who often engage in intentional car following and pursuits.
David Crundall; Peter Chapman; Emma France; Geoffrey Underwood; Nicola Phelps
What attracts attention during police pursuit driving? Journal Article
In: Applied Cognitive Psychology, vol. 19, no. 4, pp. 409–420, 2005.
Efficient deployment of attention is important to the safe execution of tasks with a high content of visual information, such as driving. Chasing a lead vehicle is an extremely demanding and dangerous task, though little is known of the visual skills required. A study is reported that recorded the eye movements of police drivers and two control groups (novices and age- and experienced- matched controls) while watching a series of video clips of driving. The clips included pursuits, emergency response drives, and control drives (at normal speeds) around Nottinghamshire, UK. Analysis of gaze durations within certain categories of stimuli revealed that daytime pursuit drives correspond with an increase in gaze durations on a lead car (controlled for exposure), though police drivers direct their attention to other sources of potential hazards, such as pedestrians, more so than other drivers.
David Crundall; Editha M van Loon; Geoffrey Underwood
In: Accident Analysis & Prevention, vol. 38, no. 4, pp. 671–677, 2006.
The optimum positioning of roadside advertisements is recognized by the industry as an important factor in attracting the attention of passing drivers. Less acknowledged is the possibility that the location of an advertisement may distract attention from vital driving-related information. This study compared street-level advertisements (SLAs; predominantly bus shelters) with raised-level advertisements (RLAs) of the same size that were suspended 3 m above the ground, on their ability to attract attention under different task conditions. Participants were split into two groups and watched video clips of driving, rating them for hazardousness while their eye movements were recorded. One of the groups was additionally primed to attend to advertisements. SLAs received the most fixations when participants were solely looking for hazards, and the fewest fixations when primed to look for advertisements. Though SLAs also had longer fixations than the RLAs, they were more poorly recognized in a subsequent memory test. We conclude that SLAs attract and hold attention at inappropriate times compared to raised-level advertisements.
Joe Cutting; Paul Cairns
In: Behaviour and Information Technology, pp. 1–21, 2020.
Digital games are well known for holding players' attention and stopping them from being distracted by events around them. Being able to quantify how well games hold attention provides a behavioral foundation for measures of game engagement and a link to existing research on attention. We developed a new behavioral measure of how well games hold attention, based on players' post-game recognition of irrelevant distractors which are shown around the game. This is known as the Distractor Recognition Paradigm (DRP). In two studies we show that the DRP is an effective measure of how well self-paced games hold attention. We show that even simple self-paced games can hold players' attention completely and the consistency of attentional focus is moderated by game engagement. We compare the DRP to existing measures of both attention and engagement and consider how practical it is as a measure of game engagement. We find no evidence that eye tracking is a superior measure of attention to distractor recognition. We discuss existing research on attention and consider implications for areas such as motivation to play and serious games.
Joke Daems; Sonia Vandepitte; Robert J Hartsuiker; Lieve Macken
In: Meta: Journal des traducteurs, vol. 62, no. 2, pp. 245–270, 2017.
While the benefits of using post-editing for technical texts have been more or less acknowledged, it remains unclear whether post-editing is a viable alternative to human translation for more general text types. In addition, we need a better understanding of both translation methods and how they are performed by students as well as professionals, so that pitfalls can be determined and translator training can be adapted accordingly. In this article, we aim to get a better understanding of the differences between human translation and post-editing for newspaper articles. Processes are registered by means of eye tracking and keystroke logging, which allows us to study translation speed, cognitive load, and the use of external resources. We also look at the final quality of the product as well as translators' attitude towards both methods of translation. Studying these different aspects shows that both methods and groups are more similar than anticipated.
Joke Daems; Sonia Vandepitte; Robert J Hartsuiker; Lieve Macken
In: Frontiers in Psychology, vol. 8, pp. 1–15, 2017.
Translation Environment Tools make translators' work easier by providing them with term lists, translation memories and machine translation output. Ideally, such tools automatically predict whether it is more effortful to post-edit than to translate from scratch, and determine whether or not to provide translators with machine translation output. Current machine translation quality estimation systems heavily rely on automatic metrics, even though they do not accurately capture actual post-editing effort. In addition, these systems do not take translator experience into account, even though novices' translation processes are different from those of professional translators. In this paper, we report on the impact of machine translation errors on various types of post-editing effort indicators, for professional translators as well as student translators. We compare the impact of MT quality on a product effort indicator (HTER) with that on various process effort indicators. The translation and post-editing process of student translators and professional translators was logged with a combination of keystroke logging and eye-tracking, and the MT output was analyzed with a fine-grained translation quality assessment approach. We find that most post-editing effort indicators (product as well as process) are influenced by machine translation quality, but that different error types affect different post-editing effort indicators, confirming that a more fine-grained MT quality analysis is needed to correctly estimate actual post-editing effort. Coherence, meaning shifts, and structural issues are shown to be good indicators of post-editing effort. The additional impact of experience on these interactions between MT quality and post-editing effort is smaller than expected.
Rong-Fuh Day; Gary C -W Shyi; Jyun Cheng Wang
In: Psychology and Marketing, vol. 23, no. 5, pp. 369–382, 2006.
The role of peripheral flash advertisements in decision making as a distractor or a source of arousal was examined. Participants were asked to perform multiattribute decision making in a display envi- ronment with or without banners of advertisement flashing occasion- ally in the peripheral region of the display. The flash banners acceler- ated the speed of decision making, although the participants rarely made eye movements in response to the banners or fixated their eyes on them. It was interesting to note that the participants' pupil sizes increased with the presence of flash banners. These findings suggest that rather than distracting participants' attention, flash banners appear to elevate the general level of arousal of the participants, which in turn led to making faster on-line decisions.
In: Decision Support Systems, vol. 49, no. 4, pp. 396–403, 2010.
A new generation of eye trackers shows us a promising alternative approach to tracing decision processes beyond the popular computerized-information-board approach. In order to exploit the eye-movement data, this study examined the validity of the Needleman-Wunsch algorithm (NWA) to characterize the decision process, and proposed an NWA-based classification method to predict which typical strategy an empirical search behavior might belong to. An eye-tracking based experiment was conducted. Our results showed that the resemblance score by NWA conformed to the assumption that the pair of information search behaviors based on the same strategy should have the closest resemblance. Moreover, with respect to our NWA-based classification method, our result showed that its overall prediction accuracy, hit-ratio, in identifying underlying strategies achieved 88%, significantly much higher than that gained from chance. On the whole, the combination of eye-fixation data and our NWA-based classification method is qualified.
Rong-Fuh Day; Peng Yeng Yin; Yu Chi Wang; Ching Hui Chao
In: Applied Soft Computing, vol. 48, pp. 217–229, 2016.
It is known that the decision strategy performed by a subject is implicit in his/her external behaviors. Eye movement is one of the observable external behaviors when humans are performing decision activities. Due to the dramatic increase of e-commerce volume on WWW, it is beneficial for the companies to know where the customers focus their attention on the webpage in deciding to make a purchase. This study proposes a new hybrid multi-start tabu search (HMTS) algorithm for finding the hidden decision strategies by clustering the eye-movement data obtained during the decision activities. The HMTS uses adaptive memory and employs both multi-start and local search strategies. An empirical dataset containing 294 eye-fixation sequences and a synthetic dataset consisting of 360 sequences were experimented with. We conduct the Sign test and the result shows that the proposed HMTS method significantly outperforms its variants which implement just one strategy, and the HMTS algorithm shows an improvement over genetic algorithm, particle swarm optimization, and K-means, with a level of significance $alpha$ = 0.01. The scalability and robustness of the HMTS is validated through a series of statistical tests.
Tao Deng; Kaifu Yang; Yongjie Li; Hongmei Yan
In: IEEE Transactions on Intelligent Transportation Systems, vol. 17, no. 7, pp. 2051–2062, 2016.
A traffic driving environment is a complex and dynamically changing scene. When driving, drivers always allocate their attention to the most important and salient areas or targets. Traffic saliency detection, which computes the salient and prior areas or targets in a specific driving environment, is an indispensable part of intelligent transportation systems and could be useful in supporting autonomous driving, traffic sign detection, driving training, car collision warning, and other tasks. Recently, advances in visual attention models have provided substantial progress in describing eye movements over simple stimuli and tasks such as free viewing or visual search. However, to date, there exists no computational framework that can accurately mimic a driver's gaze behavior and saliency detection in a complex traffic driving environment. In this paper, we analyzed the eye-tracking data of 40 subjects consisted of nondrivers and experienced drivers when viewing 100 traffic images. We found that a driver's attention was mostly concentrated on the end of the road in front of the vehicle. We proposed that the vanishing point of the road can be regarded as valuable top-down guidance in a traffic saliency detection model. Subsequently, we build a framework of a classic bottom-up and top-down combined traffic saliency detection model. The results show that our proposed vanishing-point-based top-down model can effectively simulate a driver's attention areas in a driving environment.
Tao Deng; Hongmei Yan; Yong Jie Li
In: IEEE Transactions on Intelligent Transportation Systems, vol. 19, no. 9, pp. 3059–3067, 2018.
Saliency detection, an important step in many computer vision applications, can, for example, predict where drivers look in a vehicular traffic environment. While many bottom-up and top-down saliency detection models have been proposed for fixation prediction in outdoor scenes, no specific attempt has been made for traffic images. Here, we propose a learning saliency detection model based on a random forest (RF) to predict drivers' fixation positions in a driving environment. First, we extract low-level (color, intensity, orientation, etc.) and high-level (e.g., the vanishing point and center bias) features and then predict the fixation points via RF-based learning. Finally, we evaluate the performance of our saliency prediction model qualitatively and quantitatively. We use quantitative evaluation metrics that include the revised receiver operating characteristic (ROC), the area under the ROC curve value, and the normalized scan-path saliency score. The experimental results on real traffic images indicate that our model can more accurately predict a driver's fixation area, while driving than the state-of-the-art bottom-up saliency models.
Jelmer P De Vries; Britta K Ischebeck; L P Voogt; Malou Janssen; Maarten A Frens; Gert Jan Kleinrensink; Josef N van der Geest
In: Physical Therapy, vol. 96, no. 8, pp. 1190–1195, 2016.
Background: Neck pain is a widespread complaint. People experiencing neck pain often present an altered timing in contraction of cervical muscles. This altered afferent information elicits the cervico-ocular reflex (COR), which stabilizes the eye in response to trunk-to-head movements. The vestibulo-ocular reflex (VOR) elicited by the vestibulum is thought to be unaffected by afferent information from the cervical spine. Objective The aim of the study was to measure the COR and VOR in people with nonspecific neck pain. Design: This study utilized a cross-sectional design in accordance with the STROBE statement. Methods: An infrared eye-tracking device was used to record the COR and the VOR while the participant was sitting on a rotating chair in darkness. Eye velocity was calculated by taking the derivative of the horizontal eye position. Parametric statistics were performed. Results: The mean COR gain in the control group (n=30) was 0.26 (SD=0.15) compared with 0.38 (SD=0.16) in the nonspecific neck pain group (n=37). Analyses of covariance were performed to analyze differences in COR and VOR gains, with age and sex as covariates. Analyses of covariance showed a significantly increased COR in participants with neck pain. The VOR between the control group, with a mean VOR of 0.67 (SD=0.17), and the nonspecific neck pain group, with a mean VOR of 0.66 (SD=0.22), was not significantly different. Limitations: Measuring eye movements while the participant is sitting on a rotating chair in complete darkness is technically complicated. Conclusions: This study suggests that people with nonspecific neck pain have an increased COR. The COR is an objective, nonvoluntary eye reflex and an unaltered VOR. This study shows that an increased COR is not restricted to patients with traumatic neck pain.
Ivan Diaz; Sabine Schmidt; Francis R Verdun; François O Bochud
Eye‐tracking of nodule detection in lung CT volumetric data Journal Article
In: Medical Physics, vol. 42, no. 6, pp. 2925–2932, 2015.
PURPOSE: Signal detection on 3D medical images depends on many factors, such as foveal and peripheral vision, the type of signal, and background complexity, and the speed at which the frames are displayed. In this paper, the authors focus on the speed with which radiologists and naïve observers search through medical images. Prior to the study, the authors asked the radiologists to estimate the speed at which they scrolled through CT sets. They gave a subjective estimate of 5 frames per second (fps). The aim of this paper is to measure and analyze the speed with which humans scroll through image stacks, showing a method to visually display the behavior of observers as the search is made as well as measuring the accuracy of the decisions. This information will be useful in the development of model observers, mathematical algorithms that can be used to evaluate diagnostic imaging systems.$backslash$n$backslash$nMETHODS: The authors performed a series of 3D 4-alternative forced-choice lung nodule detection tasks on volumetric stacks of chest CT images iteratively reconstructed in lung algorithm. The strategy used by three radiologists and three naïve observers was assessed using an eye-tracker in order to establish where their gaze was fixed during the experiment and to verify that when a decision was made, a correct answer was not due only to chance. In a first set of experiments, the observers were restricted to read the images at three fixed speeds of image scrolling and were allowed to see each alternative once. In the second set of experiments, the subjects were allowed to scroll through the image stacks at will with no time or gaze limits. In both static-speed and free-scrolling conditions, the four image stacks were displayed simultaneously. All trials were shown at two different image contrasts.$backslash$n$backslash$nRESULTS: The authors were able to determine a histogram of scrolling speeds in frames per second. The scrolling speed of the naïve observers and the radiologists at the moment the signal was detected was measured at 25-30 fps. For the task chosen, the performance of the observers was not affected by the contrast or experience of the observer. However, the naïve observers exhibited a different pattern of scrolling than the radiologists, which included a tendency toward higher number of direction changes and number of slices viewed.$backslash$n$backslash$nCONCLUSIONS: The authors have determined a distribution of speeds for volumetric detection tasks. The speed at detection was higher than that subjectively estimated by the radiologists before the experiment. The speed information that was measured will be useful in the development of 3D model observers, especially anthropomorphic model observers which try to mimic human behavior.
Carolina Diaz-Piedra; Héctor Rieiro; Juan Suárez; Francisco Rios-Tejada; Andrés Catena; Leandro Luigi Di Stasi
In: Physiological Measurement, vol. 37, no. 9, pp. N62–N75, 2016.
Fatigue is a major contributing factor to operational errors. Therefore, the validation of objective and sensitive indices to detect fatigue is critical to prevent accidents and catastrophes. Whereas tests based on saccadic velocity (SV) have become popular, their sensitivity in the military is not yet clear, since most research has been conducted in laboratory settings using not fully validated instruments. Field studies remain scarce, especially in extreme conditions such as real flights. Here, we investigated the effects of real, long flights on SV. We assessed five newly commissioned military helicopter pilots during their naviation training. Pilots flew Sikorsky S-76C helicopters, under instrumental flight rules, for more than 2 h (ca. 150 min). Eye movements were recorded before and after the flight with an eye tracker using a standard guided-saccade task. We also collected subjective ratings of fatigue. SV significantly decreased from the Pre-Flight to the Post-Flight session in all pilots by around 3% (range: 1-4%). Subjective ratings showed the same tendency. We provide conclusive evidence about the high sensitivity of fatigue tests based on SV in real flight conditions, even in small samples. This result might offer military medical departments a valid and useful biomarker of warfighter physiological state.
Giorgia D'Innocenzo; Alexander V Nowicky; Daniel T Bishop
In: Behavioural Brain Research, vol. 379, pp. 1–13, 2020.
Action observation elicits changes in primary motor cortex known as motor resonance, a phenomenon thought to underpin several functions, including our ability to understand and imitate others' actions. Motor resonance is modulated not only by the observer's motor expertise, but also their gaze behaviour. The aim of the present study was to investigate motor resonance and eye movements during observation of a dynamic goal-directed action, relative to an everyday one – a reach-grasp-lift (RGL) action, commonly used in action-observation-based neurorehabilitation protocols. Skilled and novice golfers watched videos of a golf swing and an RGL action as we recorded MEPs from three forearm muscles; gaze behaviour was concurrently monitored. Corticospinal excitability increased during golf swing observation, but it was not modulated by expertise, relative to baseline; no such changes were observed for the RGL task. MEP amplitudes were related to participants' gaze behaviour: in the RGL condition, target viewing was associated with lower MEP amplitudes; in the golf condition, MEP amplitudes were positively correlated with time spent looking at the effector or neighbouring regions. Viewing of a dynamic action such as the golf swing may enhance action observation treatment, especially when concurrent physical practice is not possible.
Leandro Luigi Di Stasi; Vanessa Álvarez-Valbuena; José J Cañas; Antonio Maldonado; Andrés Catena; Adoración Antolí; Antonio Candido
In: Transportation Research Part F: Traffic Psychology and Behaviour, vol. 12, no. 5, pp. 361–370, 2009.
We present data from an ongoing research project on the cognitive, emotional and neuropsychological basis of risk behaviour. The main aim of the project is to build a model of risk behaviour so that if we know certain cognitive, behavioural and emotional variables, we will be able to predict decisions made in the face of uncertainty and risk, with the final goal of designing programs for evaluating, preventing and controlling risk behaviour. The objective of the present study was to look for individual differences in hazard perception during a static riding simulation and their relationship with mental workload. We used a multidimensional methodology, including behavioural, subjective and physiological data. The behavioural measures were obtained in a static riding simulation during eight hazard situations. We evaluated whether eye activity measures correlated with cognitive workload and different types of risky behaviours. Eye movement parameters were measured using a video-based eye tracking system. We found that risk-prone individuals showed specific patterns of risky behaviours and that peak of saccadic velocity and subjective mental workload indexes were both reliable indicators of risk proneness. Mental workload was higher for participants showing attitudes to risk behaviours probably because of a lack of conscious awareness of specific cues indicating dangerous scenarios.
Leandro Luigi Di Stasi; Mauro Marchitto; Adoracíon Antolí; Thierry Baccino; José J Cañas
In: Journal of Air Transport Management, vol. 16, no. 6, pp. 330–333, 2010.
To assess the effects of workload pressures, participants interacted with a modified version of air traffic control simulated tasks requiring different levels of cognitive resources. Changes in mental workload between the levels were evaluated multidimensionally using a subjective rating, performance in a secondary task, and other behavioural indices. Saccadic movements were measured using a video-based eye tracking system. The Wickens multiple resource model is used as a theoretical reference framework. Saccadic peak velocity decreases with increasing cognitive load, in agreement with subjective test scores and performance data. That saccadic peak velocity is sensitive to variations in mental workload during ecologically valid tasks is demonstrated.
Leandro Luigi Di Stasi; Rebekka Renner; Peggy Staehr; Jens R Helmert; Boris M Velichkovsky; Jose J Canas; Andrés Catena; Sebastian Pannasch
In: Aviation Space and Environmental Medicine, vol. 81, no. 4, pp. 413–417, 2010.
Introduction: For research and applications in the field of (neuro)ergonomics, it is of increasing importance to have reliable methods for measuring mental workload. In the present study we examined the hypothesis that saccadic eye movements can be used for an online assessment of mental workload. Methods: Saccadic main sequence (amplitude, dura- tion and peak velocity) was used as a diagnostic measure of mental workload in a virtual driving task with three complexity levels. We tested 18 drivers in the SIRCA driving simulator while their eye movements were recorded. The Wickens' multiple resources model was used as theoretical framework. Changes in mental workload between the complexity levels were evaluated multidimensionally, using subjective rating, performance in a secondary task, and other behavioral indices. Results: Saccadic peak velocity decreased (7.2 visual °/s) as the mental workload increased, as measured by scores of mental workload test (15.2 scores) and the increase of the reaction time on the secondary task (46 ms). Discussion: Saccadic peak velocity is affected by variations in mental workload during ecologically valid tasks. We conclude that saccadic peak velocity could be a useful diagnostic index for the assessment of operators' mental workload and attentional state in hazardous environments.
Leandro Luigi Di Stasi; Adoración Antolí; José J Cañas
In: Applied Ergonomics, vol. 42, no. 6, pp. 807–813, 2011.
The primary aim of this study was to validate the saccadic main sequence, in particular the peak velocity [PV], as an alternative psychophysiological measure of Mental Workload [MW]. Taking the Wickens' multiple resource model as the theoretical framework of reference, an experiment was conducted using the Firechieftextregisteredmicroworld. MW was manipulated by changing the task complexity (between groups) and the amount of training (within groups). There were significant effects on PV from both factors. These results provide additional empirical support for the sensitivity of PV to discriminate MW variation on visual-dynamic complex tasks. These findings and other recent results on PV could provide important information for the development of a new vigilance screening tool for the prevention of accidents in several fields of applied ergonomics.
Leandro Luigi Di Stasi; Adoración Antolí; Miguel Gea; José J Cañas
In: International Journal of Industrial Ergonomics, vol. 41, no. 3, pp. 298–304, 2011.
Neuroergonomics could provide on-line methods for measuring mental effort while the operator interacts with hypermedia. We present an experimental study in which 28 participants interacted with a modified version of an existing Spanish e-commerce website in two searching tasks (Goal oriented shopping and Experiential shopping) that demand different amounts of cognitive resources. Mental workload was evaluated multidimensionally, using subjective rating, an interaction index, and eye-related indices. Eye movements and pupil diameter were recorded. The results showed visual scanning behaviour coincided with subjective test scores and performance data in showing a higher information processing load in Goal oriented shopping. However, pupil diameter was able to detect only the variation in user activation during the interaction task, a finding that replicates previous results on the validity of pupil size as an index of arousal. We conclude that a neuroergonomics approach could be a useful method for detecting variations in operators' attentional states. Relevance to industry: These results could provide important information for the development of a new attentional screening tool for the prevention of accidents in several application domains.
Leandro Luigi Di Stasi; D Contreras; Antonio Cándido; José J Cañas; A Catena
In: Transportation Research Part F: Traffic Psychology and Behaviour, vol. 14, no. 1, pp. 26–35, 2011.
Motorcyclist deaths and injuries follow the trend in sales rather than in growth in the number of motorcycles, suggesting that fatalities are related to the lack of driver experience with recently purchased motorcycles. The aim of the present investigation was to assess the effects of experience and training in hazard perception. We compared first-time riders (people who are not yet riders/drivers) before and after training in six different riding scenarios to expert motorcycle riders. Thirty-three participants took part in the experiment. Volunteers rode a moped in a fixed-base virtual environment and were presented with a number of preset risky events. We used a multidimensional methodology, including behavioral, subjective and eye-movements data. The results revealed differences between experts and first-time riders, as well as the effect of training on the novice group. As expected, training led to an improvement in the riding skills of first-time riders, reducing the number of accidents, improving their capacity to adapt their speed to the situation, reducing trajectory-corrective movements, and changing their pattern of gaze exploration. We identified several behavioral and eye-related measures that are sensitive to both long-term experience and training in motorcycle riders. These findings will be useful for the design of on-line monitoring systems to evaluate changes in risk behavior and of programs for preventing and controlling risk behavior and improving situation awareness for novice riders, with the ultimate aim of reducing road-user mortality.
Leandro Luigi Di Stasi; Rebekka Renner; Andrés Catena; José J Cañas; Boris M Velichkovsky; Sebastian Pannasch
In: Transportation Research Part C: Emerging Technologies, vol. 21, no. 1, pp. 122–133, 2012.
Developing a valid measurement of mental fatigue remains a big challenge and would be beneficial for various application areas, such as the improvement of road traffic safety. In the present study we examined influences of mental fatigue on the dynamics of saccadic eye movements. Based on previous findings, we propose that among amplitude and duration of saccades, the peak velocity of saccadic eye movements is particularly sensitive to changes in mental fatigue. Ten participants completed a fixation task before and after 2. h of driving in a virtual simulation environment as well as after a rest break of fifteen minutes. Driving and rest break were assumed to directly influence the level of mental fatigue and were evaluated using subjective ratings and eye movement indices. According to the subjective ratings, mental fatigue was highest after driving but decreased after the rest break. The peak velocity of saccadic eye movements decreased after driving while the duration of saccades increased, but no effects of the rest break were observed in the saccade parameters. We conclude that saccadic eye movement parameters-particularly the peak velocity-are sensitive indicators for mental fatigue. According to these findings, the peak velocity analysis represents a valid on-line measure for the detection of mental fatigue, providing the basis for the development of new vigilance screening tools to prevent accidents in several application domains.
Leandro Luigi Di Stasi; Adoración Antolí; José J Cañas
In: Entertainment Computing, vol. 4, no. 1, pp. 63–69, 2013.
The need to evaluate user behaviour and cognitive efforts when interacting with complex simulations plays a crucial role in many information and communications technologies. The aim of this paper is to propose the use of eye-related measures as indices of mental workload in complex tasks. An experiment was conducted using the FireChieftextregistered microworld in which user mental workload was manipulated by changing the interaction strategy required to perform a common task. There were significant effects of the attentional state of users on visual scanning behavior. Longer fixations were found for the more demanding strategy, slower saccades were found as the time-on-task increased, and pupil diameter decreased when an environmental change was introduced. Questionnaire and performance data converged with the psychophysiological ones. These results provide additional empirical support for the ability of some eye-related indices to discriminate variations in the attentional state of the user in visual-dynamic complex tasks and show their potential diagnostic capacity in the field of applied ergonomics.
Leandro Luigi Di Stasi; Andrés Catena; José J Cañas; Stephen L Macknik; Susana Martinez-Conde
Saccadic velocity as an arousal index in naturalistic tasks Journal Article
In: Neuroscience and Biobehavioral Reviews, vol. 37, no. 5, pp. 968–975, 2013.
Experimental evidence indicates that saccadic metrics vary with task difficulty and time-on-task in naturalistic scenarios. We explore historical and recent findings on the correlation of saccadic velocity with task parameters in clinical, military, and everyday situations, and its potential role in ergonomics. We moreover discuss the hypothesis that changes in saccadic velocity indicate variations in sympathetic nervous system activation; that is, variations in arousal.
Leandro Luigi Di Stasi; Michael B McCamy; Stephen L Macknik; James A Mankin; Nicole Hooft; Andrés Catena; Susana Martinez-Conde
In: Annals of Surgery, vol. 259, no. 4, pp. 824–829, 2014.
OBJECTIVE: Little is known about the effects of surgical residentsÊ fatigue on patient safety. We monitored surgical residentsÊ fatigue levels during their call day using (1) eye movement metrics, (2) objective measures of laparoscopic surgical performance, and (3) subjective reports based on standardized questionnaires. BACKGROUND: Prior attempts to investigate the effects of fatigue on surgical performance have suffered from methodological limitations, including inconsistent definitions and lack of objective measures of fatigue, and nonstandardized measures of surgical performance. Recent research has shown that fatigue can affect the characteristics of saccadic (fast ballistic) eye movements in nonsurgical scenarios. Here we asked whether fatigue induced by time-on-duty (∼24 hours) might affect saccadic metrics in surgical residents. Because saccadic velocity is not under voluntary control, a fatigue index based on saccadic velocity has the potential to provide an accurate and unbiased measure of the residentÊs fatigue level. METHODS: We measured the eye movements of members of the general surgery resident team at St. JosephÊs Hospital and Medical Center (Phoenix, AZ) (6 males and 6 females), using a head-mounted video eye tracker (similar configuration to a surgical headlight), during the performance of 3 tasks: 2 simulated laparoscopic surgery tasks (peg transfer and precision cutting) and a guided saccade task, before and after their call day. Residents rated their perceived fatigue level every 3 hours throughout their 24-hour shift, using a standardized scale. RESULTS:: Time-on-duty decreased saccadic velocity and increased subjective fatigue but did not affect laparoscopic performance. These results support the hypothesis that saccadic indices reflect graded changes in fatigue. They also indicate that fatigue due to prolonged time-on-duty does not result necessarily in medical error, highlighting the complicated relationship among continuity of care, patient safety, and fatigued providers. CONCLUSIONS: Our data show, for the first time, that saccadic velocity is a reliable indicator of the subjective fatigue of health care professionals during prolonged time-on-duty. These findings have potential impacts for the development of neuroergonomic tools to detect fatigue among health professionals and in the specifications of future guidelines regarding residentsÊ duty hours.
Leandro Luigi Di Stasi; Michael B McCamy; Sebastian Pannasch; Rebekka Renner; Andrés Catena; José J Cañas; Boris M Velichkovsky; Susana Martinez-Conde
Effects of driving time on microsaccadic dynamics Journal Article
In: Experimental Brain Research, vol. 233, no. 2, pp. 599–605, 2015.
Driver fatigue is a common cause of car acci- dents. Thus, the objective detection of driver fatigue is a first step toward the effective management of fatigue- related traffic accidents. Here, we investigated the effects of driving time, a common inducer of driver fatigue, on the dynamics of fixational eye movements. Participants drove for 2 h in a virtual driving environment while we recorded their eye movements. Microsaccade velocities decreased with driving time, suggesting a potential effect of fatigue on microsaccades during driving.
Leandro L Di Stasi; Michael B McCamy; Susana Martinez-Conde; Ellis Gayles; Chad Hoare; Michael Foster; Andrés Catena; Stephen L Macknik
In: Physiology and Behavior, vol. 153, pp. 91–96, 2016.
Aircrew fatigue is a major contributor to operational errors in civil and military aviation. Objective detection of pilot fatigue is thus critical to prevent aviation catastrophes. Previous work has linked fatigue to changes in oculomotor dynamics, but few studies have studied this relationship in critical safety environments. Here we measured the eye movements of US Marine Corps combat helicopter pilots before and after simulated flight missions of different durations. We found a decrease in saccadic velocities after long simulated flights compared to short simulated flights. These results suggest that saccadic velocity could serve as a biomarker of aviator fatigue.
Ewa Domaradzka; Maksymilian Bielecki
In: Frontiers in Psychology, vol. 8, pp. 1–11, 2017.
Numerous studies have shown that biases in visual attention might be evoked by affective and personally relevant stimuli, for example addiction-related objects. Despite the fact that addiction is often linked to specific products and systematic purchase behaviors, no studies focused directly on the existence of bias evoked by brands. Smokers are characterized by high levels of brand loyalty and everyday contact with cigarette packaging. Using the incentive-salience mechanism as a theoretical framework, we hypothesized that this group might exhibit a bias toward the preferred cigarette brand. In our study, a group of smokers (N = 40) performed a dot probe task while their eye movements were recorded. In every trial a pair of pictures was presented – each of them showed a single cigarette pack. The visual properties of stimuli were carefully controlled, so branding information was the key factor affecting subjects' reactions. For each participant, we compared gaze behavior related to the preferred vs. other brands. The analyses revealed no attentional bias in the early, orienting phase of the stimulus processing and strong differences in maintenance and disengagement. Participants spent more time looking at the preferred cigarettes and saccades starting at the preferred brand location had longer latencies. In sum, our data shows that attentional bias toward brands might be found in situations not involving choice or decision making. These results provide important insights into the mechanisms of formation and maintenance of attentiona l biases to stimuli of personal relevance and might serve as a first step toward developing new attitude measurement techniques.
Trafton Drew; Melissa L -H Võ; Alex Olwal; Francine Jacobson; Steven E Seltzer; Jeremy M Wolfe
In: Journal of Vision, vol. 13, no. 10, pp. 1–13, 2013.
Modern imaging methods like computed tomography (CT) generate 3-D volumes of image data. How do radiologists search through such images? Are certain strategies more efficient? Although there is a large literature devoted to understanding search in 2-D, relatively little is known about search in volumetric space. In recent years, with the ever-increasing popularity of volumetric medical imaging, this question has taken on increased importance as we try to understand, and ultimately reduce, errors in diagnostic radiology. In the current study, we asked 24 radiologists to search chest CTs for lung nodules that could indicate lung cancer. To search, radiologists scrolled up and down through a "stack" of 2-D chest CT "slices." At each moment, we tracked eye movements in the 2-D image plane and coregistered eye position with the current slice. We used these data to create a 3-D representation of the eye movements through the image volume. Radiologists tended to follow one of two dominant search strategies: "drilling" and "scanning." Drillers restrict eye movements to a small region of the lung while quickly scrolling through depth. Scanners move more slowly through depth and search an entire level of the lung before moving on to the next level in depth. Driller performance was superior to the scanners on a variety of metrics, including lung nodule detection rate, percentage of the lung covered, and the percentage of search errors where a nodule was never fixated.
Trafton Drew; James Guthrie; Isabel Reback
In: Journal of Experimental Psychology: Applied, vol. 26, no. 4, pp. 659–670, 2020.
Computer-aided detection (CAD) is applied during screening mammography for millions of women each year. Despite its popularity, several large studies have observed no benefit in breast cancer detection for practices that use CAD. This lack of benefit may be driven by how CAD information is conveyed to the radiologist. In the current study, we examined this possibility in an artificial task modeled after screening mammography. Prior work at high (50%) target prevalence suggested that CAD marks might disrupt visual attention: Targets that are missed by the CAD system are more likely to be missed by the user. However, targets are much less common in screening mammography. Moreover, the prior work on this topic has focused on simple binary CAD systems that place marks on likely locations, but some modern CAD systems employ interactive CAD (iCAD) systems that may mitigate the previously observed costs. Here, we examined the effects of target prevalence and CAD system. We found that the costs of binary CAD were exacerbated at low prevalence. Meanwhile, iCAD did not lead to a cost on unmarked targets, which suggests that this sort of CAD implementation may be superior to more traditional binary CAD implementations when targets occur infrequently.
Lien Dupont; Marc Antrop; Veerle Van Eetvelde
In: Landscape Research, vol. 39, no. 4, pp. 417–432, 2014.
The European Landscape Convention emphasises the need for public participation in landscape planning and management. This demands understanding of how people perceive and observe landscapes. This can objectively be measured using eye tracking, a system recording eye movements and fixations while observing images. In this study, 23 participants were asked to observe 90 landscape photographs, representing 18 landscape character types in Flanders (Belgium) differing in degree of openness and heterogeneity. For each landscape, five types of photographs were shown, varying in view angle. This experiment design allowed testing the effect of the landscape characteristics and photograph types on the observation pattern, measured by Eye-tracking Metrics (ETM). The results show that panoramic and detail photographs are observed differently than the other types. The degree of openness and heterogeneity also seems to exert a significant influence on the observation of the landscape.
Yke Bauke Eisma; Clark Borst; René van Paassen; Joost de Winter
Augmented visual feedback: Cure or distraction? Journal Article
In: Human Factors, pp. 1–13, 2020.
Objective: The aim of the study was to investigate the effect of augmented feedback on participants' workload, performance, and distribution of visual attention. Background: An important question in human–machine interface design is whether the operator should be provided with direct solutions. We focused on the solution space diagram (SSD), a type of augmented feedback that shows directly whether two aircraft are on conflicting trajectories. Method: One group of novices (n = 13) completed conflict detection tasks with SSD, whereas a second group (n = 11) performed the same tasks without SSD. Eye-tracking was used to measure visual attention distribution. Results: The mean self-reported task difficulty was substantially lower for the SSD group compared to the No-SSD group. The SSD group had a better conflict detection rate than the No-SSD group, whereas false-positive rates were equivalent. High false-positive rates for some scenarios were attributed to participants who misunderstood the SSD. Compared to the No-SSD group, the SSD group spent a large proportion of their time looking at the SSD aircraft while looking less at other areas of interest. Conclusion: Augmented feedback makes the task subjectively easier but has side effects related to visual tunneling and misunderstanding. Application: Caution should be exercised when human operators are expected to reproduce task solutions that are provided by augmented visual feedback.
Camilla E J Elphick; Graham E Pike; Graham J Hole
In: Psychology, Crime and Law, vol. 26, no. 1, pp. 67–92, 2020.
As pupil size is affected by cognitive processes, we investigated whether it could serve as an independent indicator of target recognition in lineups. Participants saw a simulated crime video, followed by two viewings of either a target-present or target-absent video lineup while pupil size was measured with an eye-tracker. Participants who made correct identifications showed significantly larger pupil sizes when viewing the target compared with distractors. Some participants were uncertain about their choice of face from the lineup, but nevertheless showed pupillary changes when viewing the target, suggesting covert recognition of the target face had occurred. The results suggest that pupillometry might be a useful aid in assessing the accuracy of an eyewitness' identification.
Ashleigh J Filtness; Vanessa Beanland
Sleep loss and change detection in driving scenes Journal Article
In: Transportation Research Part F: Traffic Psychology and Behaviour, vol. 57, pp. 10–22, 2018.
Driver sleepiness is a significant road safety problem. Sleep-related crashes occur on both urban and rural roads, yet to date driver-sleepiness research has focused on understanding impairment in rural and motorway driving. The ability to detect changes is an attention and awareness skill vital for everyday safe driving. Previous research has demonstrated that person states, such as age or motivation, influence susceptibility to change blindness (i.e., failure or delay in detecting changes). The current work considers whether sleepiness increases the likelihood of change blindness within urban and rural driving contexts. Twenty fully-licenced drivers completed a change detection ‘flicker' task twice in a counterbalanced design: once following a normal night of sleep (7–8 h) and once following sleep restriction (5 h). Change detection accuracy and response time were recorded while eye movements were continuously tracked. Accuracy was not significantly affected by sleep loss; however, following sleep loss there was some evidence of slowed change detection responses to urban images, but faster responses for rural images. Visual scanning across the images remained consistent between sleep conditions, resulting in no difference in the probability of fixating on the change target. Overall, the results suggest that sleep loss has minimal impact on change detection accuracy and visual scanning for changes in driving scenes. However, a subtle difference in response time to change detection between urban and rural images indicates that change blindness may have implications for sleep-related crashes in more visually complex urban environments. Further research is needed to confirm this finding.
Gemma Fitzsimmons; Mark J Weal; Denis Drieghe
The impact of hyperlinks on reading text Journal Article
In: PLoS ONE, vol. 14, no. 2, pp. e0210900, 2019.
There has been debate about whether blue hyperlinks on the Web cause disruption to reading. A series of eye tracking experiments were conducted to explore if coloured words in black text had any impact on reading behaviour outside and inside a Web environment. Experiment 1 and 2 explored the saliency of coloured words embedded in single sentences and the impact on reading behaviour. In Experiment 3, the effects of coloured words/hyperlinks in passages of text in a Web-like environment was explored. Experiment 1 and 2 showed that multiple coloured words in text had no negative impact on reading behaviour. However, if the sentence featured only a single coloured word, a reduction in skipping rates was observed. This suggests that the visual saliency associated with a single coloured word may signal to the reader that the word is important, whereas this signalling is reduced when multiple words are coloured. In Experiment 3, when reading passages of text containing hyperlinks in a Web environment, participants showed a tendency to re-read sentences that contained hyperlinked, uncommon words compared to hyperlinked, common words. Hyperlinks highlight important information and suggest additional content, which for more difficult concepts, invites rereading of the preceding text.
Gemma Fitzsimmons; Lewis T Jayes; Mark J Weal; Denis Drieghe
In: PLoS ONE, vol. 15, no. 9, pp. 1–23, 2020.
It has been shown that readers spend a great deal of time skim reading on the Web and that this type of reading can affect lexical processing of words. Across two experiments, we utilised eye tracking methodology to explore how hyperlinks and navigating webpages affect reading behaviour. In Experiment 1, participants read static Webpages either for comprehension or whilst skim reading, while in Experiment 2, participants additionally read through a navigable Web environment. Embedded target words were either hyperlinks or not and were either high-frequency or low-frequency words. Results from Experiment 1 show that while readers lexically process both linked and unlinked words when reading for comprehension, readers only fully lexically process linked words when skim reading, as was evidenced by a frequency effect that was absent for the unlinked words. They did fully lexically process both linked and unlinked words when reading for comprehension. In Experiment 2, which allowed for navigating, readers only fully lexically processed linked words compared to unlinked words, regardless of whether they were skim reading or reading for comprehension. We suggest that readers engage in an efficient reading strategy where they attempt to minimise comprehension loss while maintaining a high reading speed. Readers use hyperlinks as markers to suggest important information and use them to navigate through the text in an efficient and effective way. The task of reading on the Web causes readers to lexically process words in a markedly different way from typical reading experiments.
In: Applied Cognitive Psychology, vol. 25, no. 2, pp. 244–254, 2011.
The contribution of internal (eyes, nose and mouth) and external (hair-line, cheek and jaw-line) features across eyewitness identification tests was examined using eye tracking. In Experiment 1, participants studied faces and were tested with lineups, either simultaneous (test faces presented in an array) or sequential (test faces presented one at a time). In Experiment 2, the recognition of previously studied faces was tested in a showup (a suspect face alone was presented). Results indicated that foils were analysed for a shorter period of time in the simultaneous compared to the sequential condition, whereas a positively identified face was analysed for a comparable period of time across lineup procedures. In simultaneous lineups and showups, a greater proportion of time was spent analysing internal features of the test faces compared to sequential lineups. Different decision processes across eyewitness identification tests are inferred based on the results.
Heather Flowe; Garrison W Cottrell
In: Applied Cognitive Psychology, vol. 25, pp. 443–451, 2011.
Decision processes in simultaneous lineups (an array of faces in which a ‘suspect' face is displayed along with foil faces) were examined using eye tracking to capture the length and number oftimes that individual faces were visually analysed. The similarity of the lineup target face relative to the study face was manipulated, and face dwell times on the first visit and on return visits to the individual lineup faces were measured. On first visits, positively identified faces were examined for a longer duration compared to faces that were not identified. When no face was identified from the lineup, the suspect was visited for a longer duration compared to a foil face. On return visits, incorrectly identified faces were examined for a longer duration and visited more often compared to correctly identified faces. The results indicate that lineup decisions can be predicted by face dwell time and the number of visits made to faces.
Victoria Foglia; Annie Roy-Charland; Dominique Leroux; Suzanne Lemieux; Nicole Yantzi; Tina Skjonsby-McKinnon; Sylvain Fiset; Dominic Guitard
In: Canadian Journal of Experimental Psychology, pp. 1–14, 2019.
This study examined eye-movement patterns of young adults, while they were viewing texting and driving prevention advertisements, to determine which format attracts the most attention. As young adults are the most at risk for this public health issue, understanding which format is most successful at maintaining young adults' attention is especially important. Participants viewed nondriving, general distracted driving, and texting and driving advertisements. Each of these advertisement types were edited to contain text-only, image-only, and text and image content. Participants were told that they had unlimited time to view each advertisement, while their eye-movements were recorded throughout. Participants spent more time viewing the texting and driving advertisements than other types when they comprised text only. When examining differences in attention to the text and image portions of the advertisements, participants spent more time viewing the images than the text for the nondriving and general distracted driving advertisements. However, for texting and driving-specific advertisements the text-only format resulted in the most attention toward the advertisements. These results indicate that in attracting young adults' attention to texting and driving public health advertisements, the most successful format would be text-based.
Daniel Frings; John Parkin; Anne M Ridley
In: Accident Analysis & Prevention, vol. 72, pp. 411–421, 2014.
Increased frequency of cycle journeys has led to an escalation in collisions between cyclists and vehicles, particularly at shared junctions. Risks associated with passing decisions have been shown to influence cyclists' behavioural intentions. The current study extended this research by linking not only risk perception but also attention allocation (via tracking the eye movements of twenty cyclists viewing junction approaches presented on video) to behavioural intentions. These constructs were measured in a variety of contexts: junctions featuring cycle lanes, large vs. small vehicles and differing kerb to vehicle distances). Overall, cyclists devoted the majority of their attention to the nearside (side closest to kerb) of vehicles, and perceived near and offside (side furthest from kerb) passing as most risky. Waiting behind was the most frequent behavioural intention, followed by nearside and then offside passing. While cycle lane presence did not affect behaviour, it did lead to nearside passing being perceived as less risky, and to less attention being devoted to the offside. Large vehicles led to increased risk perceived with passing, and more attention directed towards the rear of vehicles, with reduced offside passing and increased intentions to remain behind the vehicle. Whether the vehicle was large or small, nearside passing was preferred around 30% of the time. Wide kerb distances increased nearside passing intentions and lower associated perceptions of risk. Additionally, relationships between attention and both risk evaluations and behaviours were observed. These results are discussed in relation to the cyclists' situational awareness and biases that various contextual factors can introduce. From these, recommendations for road safety and training are suggested.
Mathilda Froesel; Quentin Goudard; Marc Hauser; Maëva Gacoin; Suliann Ben Hamed
In: Scientific Reports, vol. 10, pp. 1–11, 2020.
Heart rate (HR) is extremely valuable in the study of complex behaviours and their physiological correlates in non-human primates. However, collecting this information is often challenging, involving either invasive implants or tedious behavioural training. In the present study, we implement a Eulerian video magnification (EVM) heart tracking method in the macaque monkey combined with wavelet transform. This is based on a measure of image to image fluctuations in skin reflectance due to changes in blood influx. We show a strong temporal coherence and amplitude match between EVM-based heart tracking and ground truth ECG, from both color (RGB) and infrared (IR) videos, in anesthetized macaques, to a level comparable to what can be achieved in humans. We further show that this method allows to identify consistent HR changes following the presentation of conspecific emotional voices or faces. EVM is used to extract HR in humans but has never been applied to non-human primates. Video photoplethysmography allows to extract awake macaques HR from RGB videos. In contrast, our method allows to extract awake macaques HR from both RGB and IR videos and is particularly resilient to the head motion that can be observed in awake behaving monkeys. Overall, we believe that this method can be generalized as a tool to track HR of the awake behaving monkey, for ethological, behavioural, neuroscience or welfare purposes.
In: PeerJ, vol. 4, pp. 1–11, 2016.
BACKGROUND: Highlighted text in the Internet (i.e., hypertext) is predominantly blue and underlined. The perceptibility of these hypertext characteristics was heavily questioned by applied research and empirical tests resulted in inconclusive results. The ability to recognize blue text in foveal and parafoveal vision was identified as potentially constrained by the low number of foveally centered blue light sensitive retinal cells. The present study investigates if foveal and parafoveal perceptibility of blue hypertext is reduced in comparison to normal black text during reading. METHODS: A silent-sentence reading study with simultaneous eye movement recordings and the invisible boundary paradigm, which allows the investigation of foveal and parafoveal perceptibility, separately, was realized (comparing fixation times after degraded vs. un-degraded parafoveal previews). Target words in sentences were presented in either black or blue and either underlined or normal. RESULTS: No effect of color and underlining, but a preview benefit could be detected for first pass reading measures. Fixation time measures that included re-reading, e.g., total viewing times, showed, in addition to a preview effect, a reduced fixation time for not highlighted (black not underlined) in contrast to highlighted target words (either blue or underlined or both). DISCUSSION: The present pattern reflects no detectable perceptual disadvantage of hyperlink stimuli but increased attraction of attention resources, after first pass reading, through highlighting. Blue or underlined text allows readers to easily perceive hypertext and at the same time readers re-visited highlighted words longer. On the basis of the present evidence, blue hypertext can be safely recommended to web designers for future use.
Susan M Gass; Paula Winke; Daniel R Isbell; Jieun Ahn
In: Language Learning and Technology, vol. 23, no. 2, pp. 84–104, 2019.
Captions provide a useful aid to language learners for comprehending videos and learning new vocabulary, aligning with theories of multimedia learning. Multimedia learning predicts that a learner's working memory (WM) influences the usefulness of captions. In this study, we present two eye-tracking experiments investigating the role of WM in captioned video viewing behavior and comprehension. In Experiment 1, Spanish-as-a-foreign-language learners differed in caption use according to their level of comprehension and to a lesser extent, their WM capacities. WM did not impact comprehension. In Experiment 2, English-as-a-second-language learners differed in comprehension according to their WM capacities. Those with high comprehension and high WM used captions less on a second viewing. These findings highlight the effects of potential individual differences and have implications for the integration of multimedia with captions in instructed language learning. We discuss how captions may help neutralize some of working memory's limiting effects on learning.
Agostino Gibaldi; Silvio P Sabatini
In: Behavior Research Methods, pp. 1–21, 2020.
Saccades are rapid ballistic eye movements that humans make to direct the fovea to an object of interest. Their kinematics is well defined, showing regular relationships between amplitude, duration, and velocity: the saccadic 'main sequence'. Deviations of eye movements from the main sequence can be used as markers of specific neurological disorders. Despite its significance, there is no general methodological consensus for reliable and repeatable measurements of the main sequence. In this work, we propose a novel approach for standard indicators of oculomotor performance. The obtained measurements are characterized by high repeatability, allowing for fine assessments of inter- and intra-subject variability, and inter-ocular differences. The designed experimental procedure is natural and non-fatiguing, thus it is well suited for fragile or non-collaborative subjects like neurological patients and infants. The method has been released as a software toolbox for public use. This framework lays the foundation for a normative dataset of healthy oculomotor performance for the assessment of oculomotor dysfunctions.
Elizabeth Gilman; Geoffrey Underwood
In: Visual Cognition, vol. 10, no. 2, pp. 201–232, 2003.
An experiment is reported, which was designed to determine how the perceptual span of pianists varies with developing skill and cognitive load. Eye-movements were recorded as musical phrases were presented through a gaze-contingent window, which contained one beat, two beats, or four beats. In a control condition, the music was presented without a window. The pianists were required to perform three tasks of varying cognitive load: An error-detection task (low load); a sight- reading task (medium load); and a transposition task (high load). Measures taken comprised fixation duration, fixation frequency, saccade length, fixation locations, performance duration, note duration, position of first error, number of errors, and eye±hand span. The results indicate that good and poor sight-readers do not differ in terms of perceptual span. However, good sight-readers were found to have larger eye±hand spans. Furthermore, the results show that increasing cognitive load decreases eye±hand span, but has little effect on perceptual span.