All EyeLink usability and applied research publications are listed below in alphabetical order based on the first author. You can search the publications using key words such as Driving, Sport, Workload, etc. You can also search for individual author names. If we missed any EyeLink usability or applied article, please email us!
Dimitris Agrafiotis; Nishan Canagarajah; David R Bull; Matthew Dye Perceptually optimised sign language video coding based on eye tracking analysis Journal Article Electronics Letters, 39 , pp. 1–2, 2003. @article{Agrafiotis2003, title = {Perceptually optimised sign language video coding based on eye tracking analysis}, author = {Dimitris Agrafiotis and Nishan Canagarajah and David R Bull and Matthew Dye}, doi = {10.1049/el}, year = {2003}, date = {2003-01-01}, journal = {Electronics Letters}, volume = {39}, pages = {1--2}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 A perceptually optimised video coding system for sign language communication at low bit rates Journal Article Signal Processing: Image Communication, 21 (7), pp. 531–549, 2006. @article{Agrafiotis2006, title = {A perceptually optimised video coding system for sign language communication at low bit rates}, author = {Dimitris Agrafiotis and Nishan Canagarajah and David R Bull and Jim Kyle and Helen Seers and Matthew Dye}, doi = {10.1016/j.image.2006.02.003}, year = {2006}, date = {2006-01-01}, journal = {Signal Processing: Image Communication}, volume = {21}, number = {7}, pages = {531--549}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Avigael M Aizenman; Trafton Drew; Krista A Ehinger; Dianne Georgian-smith; Jeremy M Wolfe Comparing search patterns in digital breast tomosynthesis and full-field digital mammography: An eye tracking study Journal Article Journal of Medical Imaging, 4 (4), pp. 1–22, 2017. @article{Aizenman2017, title = {Comparing search patterns in digital breast tomosynthesis and full-field digital mammography: An eye tracking study}, author = {Avigael M Aizenman and Trafton Drew and Krista A Ehinger and Dianne Georgian-smith and Jeremy M Wolfe}, doi = {10.1117/1.JMI.4.4.045501}, year = {2017}, date = {2017-01-01}, journal = {Journal of Medical Imaging}, volume = {4}, number = {4}, pages = {1--22}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Hosam Al-Samarraie; Samer Muthana Sarsam; Hans Guesgen Predicting user preferences of environment design: A perceptual mechanism of user interface customisation Journal Article Behaviour & Information Technology, 35 (8), pp. 644–653, 2016. @article{Al-Samarraie2016, title = {Predicting user preferences of environment design: A perceptual mechanism of user interface customisation}, author = {Hosam Al-Samarraie and Samer Muthana Sarsam and Hans Guesgen}, doi = {10.1080/0144929X.2016.1186735}, year = {2016}, date = {2016-01-01}, journal = {Behaviour & Information Technology}, volume = {35}, number = {8}, pages = {644--653}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Denis Alamargot Eye and Pen: A new device for studying reading Journal Article Behavior Research Methods, 38 (2), pp. 287–299, 2006. @article{Alamargot2006, title = {Eye and Pen: A new device for studying reading}, author = {Denis Alamargot}, year = {2006}, date = {2006-01-01}, journal = {Behavior Research Methods}, volume = {38}, number = {2}, pages = {287--299}, abstract = {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}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Quantifying the importance of preserving video quality in visually important regions at the expense of background content Journal Article Signal Processing: Image Communication, 32 , pp. 69–80, 2015. @article{Alers2015, title = {Quantifying the importance of preserving video quality in visually important regions at the expense of background content}, author = {Hani Alers and Judith A Redi and Ingrid Heynderickx}, doi = {10.1016/j.image.2015.01.006}, year = {2015}, date = {2015-01-01}, journal = {Signal Processing: Image Communication}, volume = {32}, pages = {69--80}, publisher = {Elsevier}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
George J Andersen; Rui Ni; Zheng Bian; Julie Kang Limits of spatial attention in three-dimensional space and dual-task driving performance Journal Article Accident Analysis & Prevention, 43 (1), pp. 381–390, 2011. @article{Andersen2011, title = {Limits of spatial attention in three-dimensional space and dual-task driving performance}, author = {George J Andersen and Rui Ni and Zheng Bian and Julie Kang}, doi = {10.1016/j.aap.2010.09.007}, year = {2011}, date = {2011-01-01}, journal = {Accident Analysis & Prevention}, volume = {43}, number = {1}, pages = {381--390}, publisher = {Elsevier Ltd}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Behavior Research Methods, 43 , pp. 843–852, 2011. @article{Anderson2011, title = {Exploiting human sensitivity to gaze for tracking the eyes}, author = {Nicola C Anderson and Evan F Risko and Alan Kingstone}, doi = {10.3758/s13428-011-0078-8}, year = {2011}, date = {2011-01-01}, journal = {Behavior Research Methods}, volume = {43}, pages = {843--852}, abstract = {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).}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Establishing the duration of crimes: An individual differences and eye-tracking investigation into time estimation Journal Article Applied Cognitive Psychology, 28 (2), pp. 215–225, 2014. @article{Attard2014, title = {Establishing the duration of crimes: An individual differences and eye-tracking investigation into time estimation}, author = {Janice Attard and Markus Bindemann}, doi = {10.1002/acp.2986}, year = {2014}, date = {2014-01-01}, journal = {Applied Cognitive Psychology}, volume = {28}, number = {2}, pages = {215--225}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Elham Azizi; Larry Allen Abel; Matthew J Stainer The influence of action video game playing on eye movement behaviour during visual search in abstract, in-game and natural scenes Journal Article Attention, Perception, & Psychophysics, 79 (2), pp. 484–497, 2017. @article{Azizi2017, title = {The influence of action video game playing on eye movement behaviour during visual search in abstract, in-game and natural scenes}, author = {Elham Azizi and Larry Allen Abel and Matthew J Stainer}, doi = {10.3758/s13414-016-1256-7}, year = {2017}, date = {2017-01-01}, journal = {Attention, Perception, & Psychophysics}, volume = {79}, number = {2}, pages = {484--497}, publisher = {Attention, Perception, & Psychophysics}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 PLoS ONE, 8 (9), pp. 1–8, 2013. @article{Baker2013, title = {Visual attention and the neuroimage bias}, author = {D A Baker and N J Schweitzer and Evan F Risko and Jillian M Ware}, doi = {10.1371/journal.pone.0074449}, year = {2013}, date = {2013-01-01}, journal = {PLoS ONE}, volume = {8}, number = {9}, pages = {1--8}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Journal of Research in Interactive Marketing, 7 (2), pp. 119–139, 2013. @article{Barreto2013, title = {Do users look at banner ads on Facebook?}, author = {Ana Margarida Barreto}, doi = {10.1108/JRIM-Mar-2012-0013}, year = {2013}, date = {2013-01-01}, journal = {Journal of Research in Interactive Marketing}, volume = {7}, number = {2}, pages = {119--139}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Macko An engineering model of human balance control—Part I: Biomechanical model Journal Article Journal of Biomechanical Engineering, 138 (1), pp. 1–11, 2016. @article{Barton2016b, title = {An engineering model of human balance control—Part I: Biomechanical model}, author = {Joseph E Barton and Anindo Roy and John D Sorkin and Mark W Rogers and Richard Macko}, doi = {10.1115/1.4031486}, year = {2016}, date = {2016-01-01}, journal = {Journal of Biomechanical Engineering}, volume = {138}, number = {1}, pages = {1--11}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Y Behnke Visual qualities of future geography books Journal Article European Journal of Geography, 5 (4), pp. 56–66, 2014. @article{Behnke2014, title = {Visual qualities of future geography books}, author = {Y Behnke}, year = {2014}, date = {2014-01-01}, journal = {European Journal of Geography}, volume = {5}, number = {4}, pages = {56--66}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Palash Bera; Louis Philippe Sirois Displaying background maps in business intelligence dashboards Journal Article Iranian Journal of Psychiatry, 18 (5), pp. 58–65, 2016. @article{Bera2016, title = {Displaying background maps in business intelligence dashboards}, author = {Palash Bera and Louis Philippe Sirois}, doi = {10.1109/MITP.2016.78}, year = {2016}, date = {2016-01-01}, journal = {Iranian Journal of Psychiatry}, volume = {18}, number = {5}, pages = {58--65}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Examining the link between framed physical activity ads and behavior among women Journal Article Journal of Sport and Exercise Psychology, 36 (3), pp. 271–280, 2014. @article{Berenbaum2014, title = {Examining the link between framed physical activity ads and behavior among women}, author = {Erin Berenbaum and Amy E Latimer-Cheung}, doi = {10.1123/jsep.2013-0207}, year = {2014}, date = {2014-01-01}, journal = {Journal of Sport and Exercise Psychology}, volume = {36}, number = {3}, pages = {271--280}, abstract = {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}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 The effect of expertise on eye movement behaviour in medical image perception Journal Article PLoS ONE, 8 (6), pp. 1–15, 2013. @article{Bertram2013, title = {The effect of expertise on eye movement behaviour in medical image perception}, author = {Raymond Bertram and Laura Helle and Johanna K Kaakinen and Erkki Svedström}, doi = {10.1371/journal.pone.0066169}, year = {2013}, date = {2013-01-01}, journal = {PLoS ONE}, volume = {8}, number = {6}, pages = {1--15}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Kaakinen; Frank Bensch; Laura Helle; Eila Lantto; Pekka Niemi; Nina Lundbom Eye movements of radiologists reflect expertise in CT study interpretation: A potential tool to measure resident development Journal Article Radiology, 281 (3), pp. 805–815, 2016. @article{Bertram2016, title = {Eye movements of radiologists reflect expertise in CT study interpretation: A potential tool to measure resident development}, author = {Raymond Bertram and Johanna Kaakinen and Frank Bensch and Laura Helle and Eila Lantto and Pekka Niemi and Nina Lundbom}, doi = {10.1148/radiol.2016151255}, year = {2016}, date = {2016-01-01}, journal = {Radiology}, volume = {281}, number = {3}, pages = {805--815}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Pitch discrimination in musicians and non-musicians: Effects of harmonic resolvability and processing effort Journal Article Journal of the Association for Research in Otolaryngology, 17 (1), pp. 69–79, 2016. @article{Bianchi2016, title = {Pitch discrimination in musicians and non-musicians: Effects of harmonic resolvability and processing effort}, author = {Federica Bianchi and Sébastien Santurette and Dorothea Wendt and Torsten Dau}, doi = {10.1007/s10162-015-0548-2}, year = {2016}, date = {2016-01-01}, journal = {Journal of the Association for Research in Otolaryngology}, volume = {17}, number = {1}, pages = {69--79}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Scientific Reports, 7 (1), pp. 1–6, 2017. @article{Binetti2017, title = {Pupil response hazard rates predict perceived gaze durations}, author = {Nicola Binetti and Charlotte Harrison and Isabelle Mareschal and Alan Johnston}, doi = {10.1038/s41598-017-04249-9}, year = {2017}, date = {2017-12-01}, journal = {Scientific Reports}, volume = {7}, number = {1}, pages = {1--6}, publisher = {Springer US}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Telling people where to look in a soccer-based decision task: A nomothetic approach Journal Article Journal of Eye Movement Research, 7 (2), pp. 1–13, 2014. @article{Bishop2014, title = {Telling people where to look in a soccer-based decision task: A nomothetic approach}, author = {Daniel Bishop and Gustav Kuhn and Claire Maton}, doi = {10.16910/jemr.7.2.1}, year = {2014}, date = {2014-01-01}, journal = {Journal of Eye Movement Research}, volume = {7}, number = {2}, pages = {1--13}, publisher = {Anomothetic}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 EEG and eye tracking demonstrate vigilance enhancement with challenge integration Journal Article Frontiers in Human Neuroscience, 10 , pp. 1–12, 2016. @article{Bodala2016, title = {EEG and eye tracking demonstrate vigilance enhancement with challenge integration}, author = {Indu P Bodala and Junhua Li and Nitish V Thakor and Hasan Al-Nashash}, doi = {10.3389/fnhum.2016.00273}, year = {2016}, date = {2016-01-01}, journal = {Frontiers in Human Neuroscience}, volume = {10}, pages = {1--12}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Hanneke Bouwsema; Corry K Van Der Sluis; Raoul M Bongers Changes in performance over time while learning to use a myoelectric prosthesis Journal Article Journal of NeuroEngineering and Rehabilitation, 11 (1), pp. 1–15, 2014. @article{Bouwsema2014, title = {Changes in performance over time while learning to use a myoelectric prosthesis}, author = {Hanneke Bouwsema and Corry K {Van Der Sluis} and Raoul M Bongers}, doi = {10.1186/1743-0003-11-16}, year = {2014}, date = {2014-01-01}, journal = {Journal of NeuroEngineering and Rehabilitation}, volume = {11}, number = {1}, pages = {1--15}, publisher = {Journal of NeuroEngineering and Rehabilitation}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Eye tracking under dichoptic viewing conditions: A practical solution Journal Article Behavior Research Methods, 49 (4), pp. 1303–1309, 2017. @article{Brascamp2017, title = {Eye tracking under dichoptic viewing conditions: A practical solution}, author = {Jan W Brascamp and Marnix Naber}, doi = {10.3758/s13428-016-0805-2}, year = {2017}, date = {2017-01-01}, journal = {Behavior Research Methods}, volume = {49}, number = {4}, pages = {1303--1309}, publisher = {Behavior Research Methods}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Tom Bullock; James C Elliott; John T Serences; Barry Giesbrecht Acute exercise modulates feature-selective responses in human cortex Journal Article Journal of Cognitive Neuroscience, 29 (4), pp. 605–618, 2016. @article{Bullock2016, title = {Acute exercise modulates feature-selective responses in human cortex}, author = {Tom Bullock and James C Elliott and John T Serences and Barry Giesbrecht}, year = {2016}, date = {2016-01-01}, journal = {Journal of Cognitive Neuroscience}, volume = {29}, number = {4}, pages = {605--618}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Aurélie Calabrèse; Carlos Aguilar; Géraldine Faure; Frédéric Matonti; Louis Hoffart; Eric Castet A vision enhancement system to improve face recognition with central vision loss Journal Article Optometry and Vision Science, 95 (9), pp. 738–746, 2018. @article{Calabrese2018, title = {A vision enhancement system to improve face recognition with central vision loss}, author = {Aurélie Calabr{è}se and Carlos Aguilar and Géraldine Faure and Frédéric Matonti and Louis Hoffart and Eric Castet}, doi = {10.1097/OPX.0000000000001263}, year = {2018}, date = {2018-01-01}, journal = {Optometry and Vision Science}, volume = {95}, number = {9}, pages = {738--746}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Journal of Cognitive Psychology, 23 (3), pp. 302–310, 2011. @article{Canal-Bruland2011, title = {Visual span and change detection in soccer: An expertise study}, author = {Rouwen Ca{ñ}al-Bruland and Simone Lotz and Norbert Hagemann and Jörg Schorer and Bernd Strauss}, doi = {10.1080/20445911.2011.496723}, year = {2011}, date = {2011-01-01}, journal = {Journal of Cognitive Psychology}, volume = {23}, number = {3}, pages = {302--310}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Effects of knowledge and display design on comprehension of complex graphics Journal Article Learning and Instruction, 20 (2), pp. 155–166, 2010. @article{Canham2010, title = {Effects of knowledge and display design on comprehension of complex graphics}, author = {Matt Canham and Mary Hegarty}, doi = {10.1016/j.learninstruc.2009.02.014}, year = {2010}, date = {2010-01-01}, journal = {Learning and Instruction}, volume = {20}, number = {2}, pages = {155--166}, publisher = {Elsevier Ltd}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Etzel Cardeña; Barbara Nordhjem; David Marcusson-Clavertz; Kenneth Holmqvist The "hypnotic state" and eye movements: Less there than meets the eye? Journal Article PLoS ONE, 12 (8), pp. 1–17, 2017. @article{Cardena2017, title = {The "hypnotic state" and eye movements: Less there than meets the eye?}, author = {Etzel Carde{ñ}a and Barbara Nordhjem and David Marcusson-Clavertz and Kenneth Holmqvist}, doi = {10.1371/journal.pone.0182546}, year = {2017}, date = {2017-01-01}, journal = {PLoS ONE}, volume = {12}, number = {8}, pages = {1--17}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Eyetracking for two-person tasks with manipulation of a virtual world Journal Article Behavior Research Methods, 42 (1), pp. 254–265, 2010. @article{Carletta2010, title = {Eyetracking for two-person tasks with manipulation of a virtual world}, author = {Jean Carletta and Robin L Hill and Craig Nicol and Tim Taylor and Jan Peter de Ruiter and Ellen Gurman Bard}, doi = {10.3758/BRM.42.1.254}, year = {2010}, date = {2010-01-01}, journal = {Behavior Research Methods}, volume = {42}, number = {1}, pages = {254--265}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Benedetta Cesqui; Maura Mezzetti; Francesco Lacquaniti; Andrea D'Avella Gaze behavior in one-handed catching and its relation with interceptive performance: What the eyes can't tell Journal Article PloS one, 10 (3), pp. 1–39, 2015. @article{Cesqui2015, title = {Gaze behavior in one-handed catching and its relation with interceptive performance: What the eyes can't tell}, author = {Benedetta Cesqui and Maura Mezzetti and Francesco Lacquaniti and Andrea D'Avella}, doi = {10.1371/journal.pone.0119445}, year = {2015}, date = {2015-01-01}, journal = {PloS one}, volume = {10}, number = {3}, pages = {1--39}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 A computational cognitive model of information search in textual materials Journal Article Cognitive Computation, 6 (1), pp. 1–17, 2014. @article{Chanceaux2014a, title = {A computational cognitive model of information search in textual materials}, author = {Myriam Chanceaux and Anne Guérin-Dugué and Beno{î}t Lemaire and Thierry Baccino}, doi = {10.1007/s12559-012-9200-1}, year = {2014}, date = {2014-01-01}, journal = {Cognitive Computation}, volume = {6}, number = {1}, pages = {1--17}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 What's the risk? A comparison of actual and perceived driving risk Journal Article Transportation Research Part F: Traffic Psychology and Behaviour, 25 , pp. 50–64, 2014. @article{Charlton2014, title = {What's the risk? A comparison of actual and perceived driving risk}, author = {Samuel G Charlton and Nicola J Starkey and John A Perrone and Robert B Isler}, doi = {10.1016/j.trf.2014.05.003}, year = {2014}, date = {2014-01-01}, journal = {Transportation Research Part F: Traffic Psychology and Behaviour}, volume = {25}, pages = {50--64}, publisher = {Elsevier Ltd}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Mina Choi; Joel Wang; Wei Chung Cheng; Giovanni Ramponi; Luigi Albani; Aldo Badano Effect of veiling glare on detectability in high-dynamic-range medical images Journal Article Journal of Display Technology, 10 (5), pp. 420–428, 2014. @article{Choi2014a, title = {Effect of veiling glare on detectability in high-dynamic-range medical images}, author = {Mina Choi and Joel Wang and Wei Chung Cheng and Giovanni Ramponi and Luigi Albani and Aldo Badano}, doi = {10.1109/JDT.2013.2279933}, year = {2014}, date = {2014-01-01}, journal = {Journal of Display Technology}, volume = {10}, number = {5}, pages = {420--428}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Sauman Chu; Nora Paul; Laura Ruel Using eye tracking technology to examine the effectiveness of design elements on news websites Journal Article Information Design Journal, 17 (1), pp. 31–43, 2009. @article{Chu2009, title = {Using eye tracking technology to examine the effectiveness of design elements on news websites}, author = {Sauman Chu and Nora Paul and Laura Ruel}, doi = {10.1075/idj.17.1.04chu}, year = {2009}, date = {2009-01-01}, journal = {Information Design Journal}, volume = {17}, number = {1}, pages = {31--43}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Archives of Ophthalmology, 120 (11), pp. 1509–1516, 2002. @article{Coeckelbergh2002a, title = {The effect of visual field defects on driving performance}, author = {Tanja R M Coeckelbergh}, doi = {10.1001/archopht.120.11.1509}, year = {2002}, date = {2002-01-01}, journal = {Archives of Ophthalmology}, volume = {120}, number = {11}, pages = {1509--1516}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 The effect of visual field defects on eye movements and practical fitness to drive Journal Article Vision Research, 42 (5), pp. 669–677, 2002. @article{Coeckelbergh2002b, title = {The effect of visual field defects on eye movements and practical fitness to drive}, author = {Tanja R M Coeckelbergh and Frans W Cornelissen and Wiebo H Brouwer and Aart C Kooijman}, doi = {10.1016/S0042-6989(01)00297-8}, year = {2002}, date = {2002-01-01}, journal = {Vision Research}, volume = {42}, number = {5}, pages = {669--677}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Comparing two types of engineering visualizations: Task-related manipulations matter Journal Article Applied Ergonomics, 43 (1), pp. 48–56, 2012. @article{Coelln2012, title = {Comparing two types of engineering visualizations: Task-related manipulations matter}, author = {Martin C Cölln and Kerstin Kusch and Jens R Helmert and Petra Kohler and Boris M Velichkovsky and Sebastian Pannasch}, doi = {10.1016/j.apergo.2011.03.005}, year = {2012}, date = {2012-01-01}, journal = {Applied Ergonomics}, volume = {43}, number = {1}, pages = {48--56}, publisher = {Elsevier Ltd}, abstract = {This study focuses on the comparison of traditional engineering drawings with a CAD (computer aided design) visualization in terms of user performance and eye movements in an applied context. Twenty-five students of mechanical engineering completed search tasks for measures in two distinct depictions of a car engine component (engineering drawing vs. CAD model). Besides spatial dimensionality, the display types most notably differed in terms of information layout, access and interaction options. The CAD visualization yielded better performance, if users directly manipulated the object, but was inferior, if employed in a conventional static manner, i.e. inspecting only predefined views. An additional eye movement analysis revealed longer fixation durations and a stronger increase of task-relevant fixations over time when interacting with the CAD visualization. This suggests a more focused extraction and filtering of information. We conclude that the three-dimensional CAD visualization can be advantageous if its ability to manipulate is used.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This study focuses on the comparison of traditional engineering drawings with a CAD (computer aided design) visualization in terms of user performance and eye movements in an applied context. Twenty-five students of mechanical engineering completed search tasks for measures in two distinct depictions of a car engine component (engineering drawing vs. CAD model). Besides spatial dimensionality, the display types most notably differed in terms of information layout, access and interaction options. The CAD visualization yielded better performance, if users directly manipulated the object, but was inferior, if employed in a conventional static manner, i.e. inspecting only predefined views. An additional eye movement analysis revealed longer fixation durations and a stronger increase of task-relevant fixations over time when interacting with the CAD visualization. This suggests a more focused extraction and filtering of information. We conclude that the three-dimensional CAD visualization can be advantageous if its ability to manipulate is used. |
Antoine Coutrot; Nathalie Guyader; Gelu Ionescu; Alice Caplier Video viewing: Do auditory salient events capture visual attention? Journal Article Annals of Telecommunications, 69 (1-2), pp. 89–97, 2014. @article{Coutrot2014a, title = {Video viewing: Do auditory salient events capture visual attention?}, author = {Antoine Coutrot and Nathalie Guyader and Gelu Ionescu and Alice Caplier}, doi = {10.1007/s12243-012-0352-5}, year = {2014}, date = {2014-01-01}, journal = {Annals of Telecommunications}, volume = {69}, number = {1-2}, pages = {89--97}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Exploring eye movements in patients with glaucoma when viewing a driving scene Journal Article PLoS ONE, 5 (3), pp. 1–10, 2010. @article{Crabb2010, title = {Exploring eye movements in patients with glaucoma when viewing a driving scene}, author = {David P Crabb and Nicholas D Smith and Franziska G Rauscher and Catharine M Chisholm and John L Barbur and David F Edgar and David F Garway-Heath}, doi = {10.1371/journal.pone.0009710}, year = {2010}, date = {2010-01-01}, journal = {PLoS ONE}, volume = {5}, number = {3}, pages = {1--10}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
David Crundall; Peter Chapman; Nicola Phelps; Geoffrey Underwood Eye movements and hazard perception in police pursuit and emergency response driving Journal Article Journal of Experimental Psychology: Applied, 9 (3), pp. 163–174, 2003. @article{Crundall2003, title = {Eye movements and hazard perception in police pursuit and emergency response driving}, author = {David Crundall and Peter Chapman and Nicola Phelps and Geoffrey Underwood}, doi = {10.1037/1076-898X.9.3.163}, year = {2003}, date = {2003-01-01}, journal = {Journal of Experimental Psychology: Applied}, volume = {9}, number = {3}, pages = {163--174}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Perception, 33 (8), pp. 975–986, 2004. @article{Crundall2004, title = {Eye movements during intentional car following}, author = {David Crundall and Claire Shenton and Geoffrey Underwood}, doi = {10.1068/p5105}, year = {2004}, date = {2004-01-01}, journal = {Perception}, volume = {33}, number = {8}, pages = {975--986}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Applied Cognitive Psychology, 19 (4), pp. 409–420, 2005. @article{Crundall2005, title = {What attracts attention during police pursuit driving?}, author = {David Crundall and Peter Chapman and Emma France and Geoffrey Underwood and Nicola Phelps}, doi = {10.1002/acp.1067}, year = {2005}, date = {2005-01-01}, journal = {Applied Cognitive Psychology}, volume = {19}, number = {4}, pages = {409--420}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Van Loon; Geoffrey Underwood Attraction and distraction of attention with roadside advertisements Journal Article Accident Analysis & Prevention, 38 (4), pp. 671–677, 2006. @article{Crundall2006, title = {Attraction and distraction of attention with roadside advertisements}, author = {David Crundall and Editha {Van Loon} and Geoffrey Underwood}, doi = {10.1016/j.aap.2005.12.012}, year = {2006}, date = {2006-01-01}, journal = {Accident Analysis & Prevention}, volume = {38}, number = {4}, pages = {671--677}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Joke Daems; Sonia Vandepitte; Robert J Hartsuiker; Lieve Macken Translation methods and experience: A comparative analysis of human translation and post-editing with students and professional translators Journal Article Meta: Journal des traducteurs, 62 (2), pp. 245–270, 2017. @article{Daems2017, title = {Translation methods and experience: A comparative analysis of human translation and post-editing with students and professional translators}, author = {Joke Daems and Sonia Vandepitte and Robert J Hartsuiker and Lieve Macken}, doi = {10.7202/1041023ar}, year = {2017}, date = {2017-01-01}, journal = {Meta: Journal des traducteurs}, volume = {62}, number = {2}, pages = {245--270}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Identifying the machine translation error types with the greatest impact on post-editing effort Journal Article Frontiers in Psychology, 8 , pp. 1–15, 2017. @article{Daems2017a, title = {Identifying the machine translation error types with the greatest impact on post-editing effort}, author = {Joke Daems and Sonia Vandepitte and Robert J Hartsuiker and Lieve Macken}, doi = {10.3389/fpsyg.2017.01282}, year = {2017}, date = {2017-08-01}, journal = {Frontiers in Psychology}, volume = {8}, pages = {1--15}, publisher = {Frontiers}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 The effect of flash banners on multiattribute decision making: Distractor or source of arousal? Journal Article Psychology and Marketing, 23 (5), pp. 369–382, 2006. @article{Day2006, title = {The effect of flash banners on multiattribute decision making: Distractor or source of arousal?}, author = {Rong-Fuh Day and Gary C -W Shyi and Jyun Cheng Wang}, doi = {10.1002/mar}, year = {2006}, date = {2006-01-01}, journal = {Psychology and Marketing}, volume = {23}, number = {5}, pages = {369--382}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Rong Fuh Day Examining the validity of the Needleman-Wunsch algorithm in identifying decision strategy with eye-movement data Journal Article Decision Support Systems, 49 (4), pp. 396–403, 2010. @article{Day2010, title = {Examining the validity of the Needleman-Wunsch algorithm in identifying decision strategy with eye-movement data}, author = {Rong Fuh Day}, doi = {10.1016/j.dss.2010.05.001}, year = {2010}, date = {2010-01-01}, journal = {Decision Support Systems}, volume = {49}, number = {4}, pages = {396--403}, publisher = {Elsevier B.V.}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 A new hybrid multi-start tabu search for finding hidden purchase decision strategies in WWW based on eye-movements Journal Article Applied Soft Computing, 48 , pp. 217–229, 2016. @article{Day2016, title = {A new hybrid multi-start tabu search for finding hidden purchase decision strategies in WWW based on eye-movements}, author = {Rong Fuh Day and Peng Yeng Yin and Yu Chi Wang and Ching Hui Chao}, doi = {10.1016/j.asoc.2016.06.041}, year = {2016}, date = {2016-01-01}, journal = {Applied Soft Computing}, volume = {48}, pages = {217--229}, publisher = {Elsevier B.V.}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Where does the driver look? Top-down-based saliency detection in a traffic driving environment Journal Article IEEE Transactions on Intelligent Transportation Systems, 17 (7), pp. 2051–2062, 2016. @article{Deng2016a, title = {Where does the driver look? Top-down-based saliency detection in a traffic driving environment}, author = {Tao Deng and Kaifu Yang and Yongjie Li and Hongmei Yan}, doi = {10.1109/TITS.2016.2535402}, year = {2016}, date = {2016-01-01}, journal = {IEEE Transactions on Intelligent Transportation Systems}, volume = {17}, number = {7}, pages = {2051--2062}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Learning to boost bottom-up fixation prediction in driving environments via random forest Journal Article IEEE Transactions on Intelligent Transportation Systems, 19 (9), pp. 3059–3067, 2018. @article{Deng2018, title = {Learning to boost bottom-up fixation prediction in driving environments via random forest}, author = {Tao Deng and Hongmei Yan and Yong Jie Li}, doi = {10.1109/TITS.2017.2766216}, year = {2018}, date = {2018-01-01}, journal = {IEEE Transactions on Intelligent Transportation Systems}, volume = {19}, number = {9}, pages = {3059--3067}, publisher = {IEEE}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Carolina Diaz-Piedra; Héctor Rieiro; Juan Suárez; Francisco Rios-Tejada; Andrés Catena; Leandro Luigi Di Stasi Fatigue in the military: Towards a fatigue detection test based on the saccadic velocity Journal Article Physiological Measurement, 37 (9), pp. N62–N75, 2016. @article{Diaz-Piedra2016, title = {Fatigue in the military: Towards a fatigue detection test based on the saccadic velocity}, author = {Carolina Diaz-Piedra and Héctor Rieiro and Juan Suárez and Francisco Rios-Tejada and Andrés Catena and Leandro Luigi {Di Stasi}}, doi = {10.1088/0967-3334/37/9/N62}, year = {2016}, date = {2016-01-01}, journal = {Physiological Measurement}, volume = {37}, number = {9}, pages = {N62--N75}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Ivan Diaz; Sabine Schmidt; Francis R Verdun; François O Bochud Eye‐tracking of nodule detection in lung CT volumetric data Journal Article Medical Physics, 42 (6), pp. 2925–2932, 2015. @article{Diaz2015, title = {Eye‐tracking of nodule detection in lung CT volumetric data}, author = {Ivan Diaz and Sabine Schmidt and Francis R Verdun and Fran{ç}ois O Bochud}, doi = {10.1118/1.4919849}, year = {2015}, date = {2015-01-01}, journal = {Medical Physics}, volume = {42}, number = {6}, pages = {2925--2932}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Leandro Luigi Di Stasi; Vanessa Álvarez-Valbuena; José J Cañas; Antonio Maldonado; Andrés Catena; Adoración Antolí; Antonio Candido Risk behaviour and mental workload: Multimodal assessment techniques applied to motorbike riding simulation Journal Article Transportation Research Part F: Traffic Psychology and Behaviour, 12 (5), pp. 361–370, 2009. @article{DiStasi2009, title = {Risk behaviour and mental workload: Multimodal assessment techniques applied to motorbike riding simulation}, author = {Leandro Luigi {Di Stasi} and Vanessa Álvarez-Valbuena and José J Ca{ñ}as and Antonio Maldonado and Andrés Catena and Adoración Antolí and Antonio Candido}, doi = {10.1016/j.trf.2009.02.004}, year = {2009}, date = {2009-01-01}, journal = {Transportation Research Part F: Traffic Psychology and Behaviour}, volume = {12}, number = {5}, pages = {361--370}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Approximation of on-line mental workload index in ATC simulated multitasks Journal Article Journal of Air Transport Management, 16 (6), pp. 330–333, 2010. @article{DiStasi2010, title = {Approximation of on-line mental workload index in ATC simulated multitasks}, author = {Leandro Luigi {Di Stasi} and Mauro Marchitto and Adoracíon Antolí and Thierry Baccino and José J Ca{ñ}as}, doi = {10.1016/j.jairtraman.2010.02.004}, year = {2010}, date = {2010-01-01}, journal = {Journal of Air Transport Management}, volume = {16}, number = {6}, pages = {330--333}, publisher = {Elsevier Ltd}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Saccadic Peak Velocity Sensitivity to Variations in Mental Workload Journal Article Aviation Space and Environmental Medicine, 81 (4), pp. 413–417, 2010. @article{DiStasi2010a, title = {Saccadic Peak Velocity Sensitivity to Variations in Mental Workload}, author = {Leandro Luigi {Di Stasi} and Rebekka Renner and Peggy Staehr and Jens R Helmert and Boris M Velichkovsky and Jose J Canas and Andrés Catena and Sebastian Pannasch}, doi = {10.3357/ASEM.2579.2010}, year = {2010}, date = {2010-01-01}, journal = {Aviation Space and Environmental Medicine}, volume = {81}, number = {4}, pages = {413--417}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Juan Cañas Main sequence: An index for detecting mental workload variation in complex tasks Journal Article Applied Ergonomics, 42 (6), pp. 807–813, 2011. @article{DiStasi2011a, title = {Main sequence: An index for detecting mental workload variation in complex tasks}, author = {Leandro Luigi {Di Stasi} and Adoración Antolí and José Juan Ca{ñ}as}, doi = {10.1016/j.apergo.2011.01.003}, year = {2011}, date = {2011-01-01}, journal = {Applied Ergonomics}, volume = {42}, number = {6}, pages = {807--813}, publisher = {Elsevier Ltd}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 A neuroergonomic approach to evaluating mental workload in hypermedia interactions Journal Article International Journal of Industrial Ergonomics, 41 (3), pp. 298–304, 2011. @article{DiStasi2011b, title = {A neuroergonomic approach to evaluating mental workload in hypermedia interactions}, author = {Leandro Luigi {Di Stasi} and Adoración Antolí and Miguel Gea and José J Ca{ñ}as}, doi = {10.1016/j.ergon.2011.02.008}, year = {2011}, date = {2011-01-01}, journal = {International Journal of Industrial Ergonomics}, volume = {41}, number = {3}, pages = {298--304}, publisher = {Elsevier Ltd}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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; A Cándido; J J Cañas; A Catena Behavioral and eye-movement measures to track improvements in driving skills of vulnerable road users: First-time motorcycle riders Journal Article Transportation Research Part F: Traffic Psychology and Behaviour, 14 (1), pp. 26–35, 2011. @article{DiStasi2011c, title = {Behavioral and eye-movement measures to track improvements in driving skills of vulnerable road users: First-time motorcycle riders}, author = {Leandro Luigi {Di Stasi} and D Contreras and A Cándido and J J Ca{ñ}as and A Catena}, doi = {10.1016/j.trf.2010.09.003}, year = {2011}, date = {2011-01-01}, journal = {Transportation Research Part F: Traffic Psychology and Behaviour}, volume = {14}, number = {1}, pages = {26--35}, publisher = {Elsevier Ltd}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Towards a driver fatigue test based on the saccadic main sequence: A partial validation by subjective report data Journal Article Transportation Research Part C: Emerging Technologies, 21 (1), pp. 122–133, 2012. @article{DiStasi2012, title = {Towards a driver fatigue test based on the saccadic main sequence: A partial validation by subjective report data}, author = {Leandro Luigi {Di Stasi} and Rebekka Renner and Andrés Catena and José J Ca{ñ}as and Boris M Velichkovsky and Sebastian Pannasch}, doi = {10.1016/j.trc.2011.07.002}, year = {2012}, date = {2012-01-01}, journal = {Transportation Research Part C: Emerging Technologies}, volume = {21}, number = {1}, pages = {122--133}, publisher = {Elsevier Ltd}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Juan Cañas Evaluating mental workload while interacting with computer-generated artificial environments Journal Article Entertainment Computing, 4 (1), pp. 63–69, 2013. @article{DiStasi2013a, title = {Evaluating mental workload while interacting with computer-generated artificial environments}, author = {Leandro Luigi {Di Stasi} and Adoración Antolí and José Juan Ca{ñ}as}, doi = {10.1016/j.entcom.2011.03.005}, year = {2013}, date = {2013-01-01}, journal = {Entertainment Computing}, volume = {4}, number = {1}, pages = {63--69}, publisher = {International Federation for Information Processing}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Neuroscience and Biobehavioral Reviews, 37 (5), pp. 968–975, 2013. @article{DiStasi2013b, title = {Saccadic velocity as an arousal index in naturalistic tasks}, author = {Leandro Luigi {Di Stasi} and Andrés Catena and José J Ca{ñ}as and Stephen L Macknik and Susana Martinez-Conde}, doi = {10.1016/j.neubiorev.2013.03.011}, year = {2013}, date = {2013-01-01}, journal = {Neuroscience and Biobehavioral Reviews}, volume = {37}, number = {5}, pages = {968--975}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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; Raúl Cabestrero; Michael B McCamy; Francisco Rios; Andrés Catena; Pilar Quirós; Jose A Lopez; Carolina Saez; Stephen L Macknik; Susana Martinez‐Conde Intersaccadic drift velocity is sensitive to short‐term hypobaric hypoxia Journal Article European Journal of Neuroscience, 39 , pp. 1384–1390, 2014. @article{DiStasi2014, title = {Intersaccadic drift velocity is sensitive to short‐term hypobaric hypoxia}, author = {Leandro Luigi {Di Stasi} and Ra{ú}l Cabestrero and Michael B McCamy and Francisco Rios and Andrés Catena and Pilar Quirós and Jose A Lopez and Carolina Saez and Stephen L Macknik and Susana Martinez‐Conde}, year = {2014}, date = {2014-01-01}, journal = {European Journal of Neuroscience}, volume = {39}, pages = {1384--1390}, abstract = {Hypoxia, defined as decreased availability of oxygen in the body's tissues, can lead to dyspnea, rapid pulse, syncope, visual dysfunction, mental disturbances such as delirium or euphoria, and even death. It is considered to be one of the most serious hazards during flight. Thus, early and objective detection of the physiological effects of hypoxia is critical to prevent catastrophes in civil and military aviation. The few studies that have addressed the effects of hypoxia on objective oculomotor metrics have had inconsistent results, however. Thus, the question of whether hypoxia modulates eye movement behavior remains open. Here we examined the effects of short-term hypobaric hypoxia on the velocity of saccadic eye movements and intersaccadic drift of Spanish Air Force pilots and flight engineers, compared with a control group that did not experience hypoxia. Saccadic velocity decreased with time-on-duty in both groups, in correlation with subjective fatigue. Intersaccadic drift velocity increased in the hypoxia group only, suggesting that acute hypoxia diminishes eye stability, independently of fatigue. Our results suggest that intersaccadic drift velocity could serve as a biomarker of acute hypoxia. These findings may also contribute to our understanding of the relationship between hypoxia episodes and central nervous system impairments.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Hypoxia, defined as decreased availability of oxygen in the body's tissues, can lead to dyspnea, rapid pulse, syncope, visual dysfunction, mental disturbances such as delirium or euphoria, and even death. It is considered to be one of the most serious hazards during flight. Thus, early and objective detection of the physiological effects of hypoxia is critical to prevent catastrophes in civil and military aviation. The few studies that have addressed the effects of hypoxia on objective oculomotor metrics have had inconsistent results, however. Thus, the question of whether hypoxia modulates eye movement behavior remains open. Here we examined the effects of short-term hypobaric hypoxia on the velocity of saccadic eye movements and intersaccadic drift of Spanish Air Force pilots and flight engineers, compared with a control group that did not experience hypoxia. Saccadic velocity decreased with time-on-duty in both groups, in correlation with subjective fatigue. Intersaccadic drift velocity increased in the hypoxia group only, suggesting that acute hypoxia diminishes eye stability, independently of fatigue. Our results suggest that intersaccadic drift velocity could serve as a biomarker of acute hypoxia. These findings may also contribute to our understanding of the relationship between hypoxia episodes and central nervous system impairments. |
Leandro Luigi Di Stasi; Michael B McCamy; Stephen L Macknik; James A Mankin; Nicole Hooft; Andrés Catena; Susana Martinez-Conde Saccadic eye movement metrics reflect surgical residents′ fatigue Journal Article Annals of Surgery, 259 (4), pp. 824–829, 2014. @article{DiStasi2014b, title = {Saccadic eye movement metrics reflect surgical residents′ fatigue}, author = {Leandro Luigi {Di Stasi} and Michael B McCamy and Stephen L Macknik and James A Mankin and Nicole Hooft and Andrés Catena and Susana Martinez-Conde}, doi = {10.1097/SLA.0000000000000260}, year = {2014}, date = {2014-01-01}, journal = {Annals of Surgery}, volume = {259}, number = {4}, pages = {824--829}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Experimental Brain Research, 233 (2), pp. 599–605, 2015. @article{DiStasi2015, title = {Effects of driving time on microsaccadic dynamics}, author = {Leandro Luigi {Di Stasi} and Michael B McCamy and Sebastian Pannasch and Rebekka Renner and Andrés Catena and José J Ca{ñ}as and Boris M Velichkovsky and Susana Martinez-Conde}, doi = {10.1007/s00221-014-4139-y}, year = {2015}, date = {2015-01-01}, journal = {Experimental Brain Research}, volume = {233}, number = {2}, pages = {599--605}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Luigi Di Stasi; Michael B McCamy; Susana Martinez-Conde; Ellis Gayles; Chad Hoare; Michael Foster; Andrés Catena; Stephen L Macknik Effects of long and short simulated flights on the saccadic eye movement velocity of aviators Journal Article Physiology & Behavior, 153 , pp. 91–96, 2016. @article{DiStasi2016, title = {Effects of long and short simulated flights on the saccadic eye movement velocity of aviators}, author = {Leandro Luigi {Di Stasi} and Michael B McCamy and Susana Martinez-Conde and Ellis Gayles and Chad Hoare and Michael Foster and Andrés Catena and Stephen L Macknik}, doi = {10.1016/j.physbeh.2015.10.024}, year = {2016}, date = {2016-01-01}, journal = {Physiology & Behavior}, volume = {153}, pages = {91--96}, publisher = {Elsevier Inc.}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Deadly attraction - attentional bias toward preferred cigarette brand in smokers Journal Article Frontiers in Psychology, 8 , pp. 1–11, 2017. @article{Domaradzka2017, title = {Deadly attraction - attentional bias toward preferred cigarette brand in smokers}, author = {Ewa Domaradzka and Maksymilian Bielecki}, doi = {10.3389/fpsyg.2017.01365}, year = {2017}, date = {2017-01-01}, journal = {Frontiers in Psychology}, volume = {8}, pages = {1--11}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 Le-Hoa Võ; Alex Olwal; Francine Jacobson; Steven E Seltzer; Jeremy M Wolfe Scanners and drillers: Characterizing expert visual search through volumetric images Journal Article Journal of Vision, 13 (10), pp. 1–13, 2013. @article{Drew2013, title = {Scanners and drillers: Characterizing expert visual search through volumetric images}, author = {Trafton Drew and Melissa Le-Hoa V{õ} and Alex Olwal and Francine Jacobson and Steven E Seltzer and Jeremy M Wolfe}, doi = {10.1167/13.10.3}, year = {2013}, date = {2013-01-01}, journal = {Journal of Vision}, volume = {13}, number = {10}, pages = {1--13}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Lien Dupont; Marc Antrop; Veerle Van Eetvelde Eye-tracking analysis in landscape perception research: Influence of photograph properties and landscape characteristics Journal Article Landscape Research, 39 (4), pp. 417–432, 2014. @article{Dupont2014, title = {Eye-tracking analysis in landscape perception research: Influence of photograph properties and landscape characteristics}, author = {Lien Dupont and Marc Antrop and Veerle {Van Eetvelde}}, doi = {10.1080/01426397.2013.773966}, year = {2014}, date = {2014-01-01}, journal = {Landscape Research}, volume = {39}, number = {4}, pages = {417--432}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Ashleigh J Filtness; Vanessa Beanland Sleep loss and change detection in driving scenes Journal Article Transportation Research Part F: Traffic Psychology and Behaviour, 57 , pp. 10–22, 2018. @article{Filtness2018, title = {Sleep loss and change detection in driving scenes}, author = {Ashleigh J Filtness and Vanessa Beanland}, doi = {10.1016/j.trf.2017.10.003}, year = {2018}, date = {2018-01-01}, journal = {Transportation Research Part F: Traffic Psychology and Behaviour}, volume = {57}, pages = {10--22}, publisher = {Elsevier Ltd}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Heather Flowe An exploration of visual behaviour in eyewitness identification tests Journal Article Applied Cognitive Psychology, 25 (2), pp. 244–254, 2011. @article{Flowe2011, title = {An exploration of visual behaviour in eyewitness identification tests}, author = {Heather Flowe}, doi = {10.1002/acp.1670}, year = {2011}, date = {2011-01-01}, journal = {Applied Cognitive Psychology}, volume = {25}, number = {2}, pages = {244--254}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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 An examination of simultaneous lineup identification decision processes using eye tracking Journal Article Applied Cognitive Psychology, 25 , pp. 443–451, 2011. @article{Flowe2011a, title = {An examination of simultaneous lineup identification decision processes using eye tracking}, author = {Heather Flowe and Garrison W Cottrell}, doi = {10.1002/acp.1711}, year = {2011}, date = {2011-01-01}, journal = {Applied Cognitive Psychology}, volume = {25}, pages = {443--451}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Daniel Frings; John Parkin; Anne M Ridley The effects of cycle lanes, vehicle to kerb distance and vehicle type on cyclists' attention allocation during junction negotiation Journal Article Accident Analysis & Prevention, 72 , pp. 411–421, 2014. @article{Frings2014, title = {The effects of cycle lanes, vehicle to kerb distance and vehicle type on cyclists' attention allocation during junction negotiation}, author = {Daniel Frings and John Parkin and Anne M Ridley}, doi = {10.1016/j.aap.2014.07.034}, year = {2014}, date = {2014-01-01}, journal = {Accident Analysis & Prevention}, volume = {72}, pages = {411--421}, publisher = {Elsevier Ltd}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Benjamin Gagl Blue hypertext is a good design decision: No perceptual disadvantage in reading and successful highlighting of relevant information Journal Article PeerJ, 4 , pp. 1–11, 2016. @article{Gagl2016, title = {Blue hypertext is a good design decision: No perceptual disadvantage in reading and successful highlighting of relevant information}, author = {Benjamin Gagl}, doi = {10.7717/peerj.2467}, year = {2016}, date = {2016-01-01}, journal = {PeerJ}, volume = {4}, pages = {1--11}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Elizabeth Gilman; Geoffrey Underwood Restricting the field of view to investigate the perceptual spans of pianists Journal Article Visual Cognition, 10 (2), pp. 201–232, 2003. @article{Gilman2003, title = {Restricting the field of view to investigate the perceptual spans of pianists}, author = {Elizabeth Gilman and Geoffrey Underwood}, doi = {10.1080/13506280244000104}, year = {2003}, date = {2003-01-01}, journal = {Visual Cognition}, volume = {10}, number = {2}, pages = {201--232}, abstract = {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.}, keywords = {}, pubstate = {published}, tppubtype = {article} } 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. |
Mackenzie G Glaholt; Grace Sim Gaze-contingent center-surround fusion of infrared images to facilitate visual search for human targets Journal Article Journal of Imaging Science and Technology, 61 (1), pp. 230–235, 2017. @article{Glaholt2017, title = {Gaze-contingent center-surround fusion of infrared images to facilitate visual search for human targets}, author = {Mackenzie G Glaholt and Grace Sim}, doi = {10.2352/J.ImagingSci.Technol.2017.61.1.010401}, year = {2017}, date = {2017-01-01}, journal = {Journal of Imaging Science and Technology}, volume = {61}, number = {1}, pages = {230--235}, abstract = {We investigated gaze-contingent fusion of infrared imagery during visual search. Eye movements were monitored while subjects searched for and identified human targets in images captured simultaneously in the short-wave (SWIR) and long-wave (LWIR) infrared bands. Based on the subject's gaze position, the search displaywas updated such that imagery from one sensorwas continuously presented to the subject's central visual field (“center”) and another sensor was presented to the subject's non-central visual field (“surround”). Analysis ofperformance data indicated that, compared to the other combinations, the scheme featuring SWIR imagery in the center region and LWIR imagery in the surround region constituted an optimal combination of the SWIR and LWIR information: it inherited the superior target detection performance of LWIR imagery and the superior target identification performance of SWIR imagery. This demonstrates a novel method for efficiently combining imagery from two infrared sources as an alternative to conventional image fusion.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We investigated gaze-contingent fusion of infrared imagery during visual search. Eye movements were monitored while subjects searched for and identified human targets in images captured simultaneously in the short-wave (SWIR) and long-wave (LWIR) infrared bands. Based on the subject's gaze position, the search displaywas updated such that imagery from one sensorwas continuously presented to the subject's central visual field (“center”) and another sensor was presented to the subject's non-central visual field (“surround”). Analysis ofperformance data indicated that, compared to the other combinations, the scheme featuring SWIR imagery in the center region and LWIR imagery in the surround region constituted an optimal combination of the SWIR and LWIR information: it inherited the superior target detection performance of LWIR imagery and the superior target identification performance of SWIR imagery. This demonstrates a novel method for efficiently combining imagery from two infrared sources as an alternative to conventional image fusion. |
Hayward J Godwin; Stuart Hyde; Dominic Taunton; James Calver; James I R Blake; Simon P Liversedge The influence of expertise on maritime driving behaviour Journal Article Applied Cognitive Psychology, 27 (4), pp. 483–492, 2013. @article{Godwin2013a, title = {The influence of expertise on maritime driving behaviour}, author = {Hayward J Godwin and Stuart Hyde and Dominic Taunton and James Calver and James I R Blake and Simon P Liversedge}, doi = {10.1002/acp.2925}, year = {2013}, date = {2013-01-01}, journal = {Applied Cognitive Psychology}, volume = {27}, number = {4}, pages = {483--492}, abstract = {We compared expert and novice behaviour in a group of participants as they engaged in a simulated maritime driving task. We varied the difficulty of the driving task by controllling the severity of the sea state in which they were driving their craft. Increases in sea severity increased the size of the upcoming waves while also increasing the length of the waves. Expert participants drove their craft at a higher speed than novices and decreased their fixation durations as wave severity increased. Furthermore, the expert participants increased the horizontal spread of their fixation positions as wave severity increased to a greater degree than novices. Conversely, novice participants showed evidence of a greater vertical spread of fixations than experts. By connecting our findings with previous research investigating eye movement behaviour and road driving, we suggest that novice or inexperienced drivers show inflexibility in adaptation to changing driving conditions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We compared expert and novice behaviour in a group of participants as they engaged in a simulated maritime driving task. We varied the difficulty of the driving task by controllling the severity of the sea state in which they were driving their craft. Increases in sea severity increased the size of the upcoming waves while also increasing the length of the waves. Expert participants drove their craft at a higher speed than novices and decreased their fixation durations as wave severity increased. Furthermore, the expert participants increased the horizontal spread of their fixation positions as wave severity increased to a greater degree than novices. Conversely, novice participants showed evidence of a greater vertical spread of fixations than experts. By connecting our findings with previous research investigating eye movement behaviour and road driving, we suggest that novice or inexperienced drivers show inflexibility in adaptation to changing driving conditions. |
Hayward J Godwin; Simon P Liversedge; Julie A Kirkby; Michael Boardman; Katherine Cornes; Nick Donnelly The influence of experience upon information-sampling and decision-making behaviour during risk assessment in military personnel Journal Article Visual Cognition, 23 (4), pp. 415–431, 2015. @article{Godwin2015, title = {The influence of experience upon information-sampling and decision-making behaviour during risk assessment in military personnel}, author = {Hayward J Godwin and Simon P Liversedge and Julie A Kirkby and Michael Boardman and Katherine Cornes and Nick Donnelly}, doi = {10.1080/13506285.2015.1030488}, year = {2015}, date = {2015-01-01}, journal = {Visual Cognition}, volume = {23}, number = {4}, pages = {415--431}, publisher = {Taylor & Francis}, abstract = {We examined the influence of experience upon information-sampling and decision-making behaviour in a group of military personnel as they conducted risk assessments of scenes photographed from patrol routes during the recent conflict in Afghanistan. Their risk assessment was based on an evaluation of Potential Risk Indicators (PRIs) during examination of each scene. We found that both participant groups were equally likely to fixate PRIs, demonstrating similarity in the selectivity of their information-sampling. However, the inexperienced participants made more revisits to PRIs, had longer response times, and were more likely to decide that the scenes contained a high level of risk. Together, these results suggest that experience primarily modulates decision-making behaviour. We discuss potential routes to train personnel to conduct risk assessments in a more similar manner to experienced participants.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We examined the influence of experience upon information-sampling and decision-making behaviour in a group of military personnel as they conducted risk assessments of scenes photographed from patrol routes during the recent conflict in Afghanistan. Their risk assessment was based on an evaluation of Potential Risk Indicators (PRIs) during examination of each scene. We found that both participant groups were equally likely to fixate PRIs, demonstrating similarity in the selectivity of their information-sampling. However, the inexperienced participants made more revisits to PRIs, had longer response times, and were more likely to decide that the scenes contained a high level of risk. Together, these results suggest that experience primarily modulates decision-making behaviour. We discuss potential routes to train personnel to conduct risk assessments in a more similar manner to experienced participants. |
Elise Grison; Valérie Gyselinck; Jean Marie Burkhardt; Jan Malte Wiener Route planning with transportation network maps: An eye-tracking study Journal Article Psychological Research, 81 (5), pp. 1020–1034, 2017. @article{Grison2017, title = {Route planning with transportation network maps: An eye-tracking study}, author = {Elise Grison and Valérie Gyselinck and Jean Marie Burkhardt and Jan Malte Wiener}, doi = {10.1007/s00426-016-0792-z}, year = {2017}, date = {2017-01-01}, journal = {Psychological Research}, volume = {81}, number = {5}, pages = {1020--1034}, abstract = {Planning routes using transportation network maps is a common task that has received little attention in the literature. Here, we present a novel eye-tracking paradigm to investigate psychological processes and mechanisms involved in such a route planning. In the experiment, participants were first presented with an origin and destination pair before we presented them with fictitious public transportation maps. Their task was to find the connecting route that required the minimum number of transfers. Based on participants' gaze behaviour, each trial was split into two phases: (1) the search for origin and destination phase, i.e., the initial phase of the trial until participants gazed at both origin and destination at least once and (2) the route planning and selection phase. Comparisons of other eye-tracking measures between these phases and the time to complete them, which depended on the complexity of the planning task, suggest that these two phases are indeed distinct and supported by different cognitive processes. For example, participants spent more time attending the centre of the map during the initial search phase, before directing their attention to connecting stations, where transitions between lines were possible. Our results provide novel insights into the psychological processes involved in route planning from maps. The findings are discussed in relation to the current theories of route planning.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Planning routes using transportation network maps is a common task that has received little attention in the literature. Here, we present a novel eye-tracking paradigm to investigate psychological processes and mechanisms involved in such a route planning. In the experiment, participants were first presented with an origin and destination pair before we presented them with fictitious public transportation maps. Their task was to find the connecting route that required the minimum number of transfers. Based on participants' gaze behaviour, each trial was split into two phases: (1) the search for origin and destination phase, i.e., the initial phase of the trial until participants gazed at both origin and destination at least once and (2) the route planning and selection phase. Comparisons of other eye-tracking measures between these phases and the time to complete them, which depended on the complexity of the planning task, suggest that these two phases are indeed distinct and supported by different cognitive processes. For example, participants spent more time attending the centre of the map during the initial search phase, before directing their attention to connecting stations, where transitions between lines were possible. Our results provide novel insights into the psychological processes involved in route planning from maps. The findings are discussed in relation to the current theories of route planning. |
Michael W von Grünau; Kamala Pilgrim; Rong Zhou Velocity discrimination thresholds for flowfield motions with moving observers Journal Article Vision Research, 47 (18), pp. 2453–2464, 2007. @article{Gruenau2007, title = {Velocity discrimination thresholds for flowfield motions with moving observers}, author = {Michael W von Grünau and Kamala Pilgrim and Rong Zhou}, doi = {10.1016/j.visres.2007.06.008}, year = {2007}, date = {2007-01-01}, journal = {Vision Research}, volume = {47}, number = {18}, pages = {2453--2464}, abstract = {The visual flow field, produced by forward locomotion, contains useful information about many aspects of visually guided behavior. But locomotion itself also contributes to possible distortions by adding head bobbing motions. Here we examine whether vertical head bobbing affects velocity discrimination thresholds and how the system may compensate for the distortions. Vertical head and eye movements while fixating were recorded during standing, walking or running on a treadmill. Bobbing noise was found to be larger during locomotion. The same observers were equally good at discriminating velocity increases in large accelerating flow fields when standing or walking or running. Simulated head bobbing was compensated when produced by pursuit eye movements, but not when it was part of the flow field. The results showed that these two contributions are additive and dealt with independently before they are combined. Distortions produced by body/head oscillations may also be compensated. Visual performance during running was at least as good as during walking, suggesting more efficient compensation mechanisms for running.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The visual flow field, produced by forward locomotion, contains useful information about many aspects of visually guided behavior. But locomotion itself also contributes to possible distortions by adding head bobbing motions. Here we examine whether vertical head bobbing affects velocity discrimination thresholds and how the system may compensate for the distortions. Vertical head and eye movements while fixating were recorded during standing, walking or running on a treadmill. Bobbing noise was found to be larger during locomotion. The same observers were equally good at discriminating velocity increases in large accelerating flow fields when standing or walking or running. Simulated head bobbing was compensated when produced by pursuit eye movements, but not when it was part of the flow field. The results showed that these two contributions are additive and dealt with independently before they are combined. Distortions produced by body/head oscillations may also be compensated. Visual performance during running was at least as good as during walking, suggesting more efficient compensation mechanisms for running. |
Katja I Häuser; Vera Demberg; Jutta Kray Psychology and Aging, 33 (8), pp. 1168–1180, 2018. @article{Haeuser2018, title = {Surprisal modulates dual-task performance in older adults: Pupillometry shows age-related trade-offs in task performance and time-course of language processing}, author = {Katja I Häuser and Vera Demberg and Jutta Kray}, doi = {10.1037/pag0000316}, year = {2018}, date = {2018-01-01}, journal = {Psychology and Aging}, volume = {33}, number = {8}, pages = {1168--1180}, abstract = {Even though older adults are known to have difficulty at language processing when a secondary task has to be performed simultaneously, few studies have addressed how older adults process language in dual-task demands when linguistic load is systematically varied. Here, we manipulated surprisal, an information theoretic measure that quantifies the amount of new information conveyed by a word, to investigate how linguistic load affects younger and older adults during early and late stages of sentence processing under conditions when attention is split between two tasks. In high-surprisal sentences, target words were implausible and mismatched with semantic expectancies based on context, thereby causing integration difficulty. Participants performed semantic meaningfulness judgments on sentences that were presented in isolation (single task) or while performing a secondary tracking task (dual task). Cognitive load was measured by means of pupillometry. Mixed-effects models were fit to the data, showing the following: (a) During the dual task, younger but not older adults demonstrated early sensitivity to surprisal (higher levels of cognitive load, indexed by pupil size) as sentences were heard online; (b) Older adults showed no immediate reaction to surprisal, but a delayed response, where their meaningfulness judgments to high-surprisal words remained stable in accuracy, while secondary tracking performance declined. Findings are discussed in relation to age-related trade-offs in dual tasking and differences in the allocation of attentional resources during language processing. Collectively, our data show that higher linguistic load leads to task trade-offs in older adults and differently affects the time course of online language processing in aging.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Even though older adults are known to have difficulty at language processing when a secondary task has to be performed simultaneously, few studies have addressed how older adults process language in dual-task demands when linguistic load is systematically varied. Here, we manipulated surprisal, an information theoretic measure that quantifies the amount of new information conveyed by a word, to investigate how linguistic load affects younger and older adults during early and late stages of sentence processing under conditions when attention is split between two tasks. In high-surprisal sentences, target words were implausible and mismatched with semantic expectancies based on context, thereby causing integration difficulty. Participants performed semantic meaningfulness judgments on sentences that were presented in isolation (single task) or while performing a secondary tracking task (dual task). Cognitive load was measured by means of pupillometry. Mixed-effects models were fit to the data, showing the following: (a) During the dual task, younger but not older adults demonstrated early sensitivity to surprisal (higher levels of cognitive load, indexed by pupil size) as sentences were heard online; (b) Older adults showed no immediate reaction to surprisal, but a delayed response, where their meaningfulness judgments to high-surprisal words remained stable in accuracy, while secondary tracking performance declined. Findings are discussed in relation to age-related trade-offs in dual tasking and differences in the allocation of attentional resources during language processing. Collectively, our data show that higher linguistic load leads to task trade-offs in older adults and differently affects the time course of online language processing in aging. |
Ziad M Hafed; Katarina Stingl; Karl Ulrich Bartz-Schmidt; Florian Gekeler; Eberhart Zrenner Oculomotor behavior of blind patients seeing with a subretinal visual implant Journal Article Vision Research, 118 , pp. 119–131, 2016. @article{Hafed2016, title = {Oculomotor behavior of blind patients seeing with a subretinal visual implant}, author = {Ziad M Hafed and Katarina Stingl and Karl Ulrich Bartz-Schmidt and Florian Gekeler and Eberhart Zrenner}, doi = {10.1016/j.visres.2015.04.006}, year = {2016}, date = {2016-01-01}, journal = {Vision Research}, volume = {118}, pages = {119--131}, publisher = {Elsevier Ltd}, abstract = {Electronic implants are able to restore some visual function in blind patients with hereditary retinal degenerations. Subretinal visual implants, such as the CE-approved Retina Implant Alpha IMS (Retina Implant AG, Reutlingen, Germany), sense light through the eye's optics and subsequently stimulate retinal bipolar cells via ~1500 independent pixels to project visual signals to the brain. Because these devices are directly implanted beneath the fovea, they potentially harness the full benefit of eye movements to scan scenes and fixate objects. However, so far, the oculomotor behavior of patients using subretinal implants has not been characterized. Here, we tracked eye movements in two blind patients seeing with a subretinal implant, and we compared them to those of three healthy controls. We presented bright geometric shapes on a dark background, and we asked the patients to report seeing them or not. We found that once the patients visually localized the shapes, they fixated well and exhibited classic oculomotor fixational patterns, including the generation of microsaccades and ocular drifts. Further, we found that a reduced frequency of saccades and microsaccades was correlated with loss of visibility. Last, but not least, gaze location corresponded to the location of the stimulus, and shape and size aspects of the viewed stimulus were reflected by the direction and size of saccades. Our results pave the way for future use of eye tracking in subretinal implant patients, not only to understand their oculomotor behavior, but also to design oculomotor training strategies that can help improve their quality of life.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Electronic implants are able to restore some visual function in blind patients with hereditary retinal degenerations. Subretinal visual implants, such as the CE-approved Retina Implant Alpha IMS (Retina Implant AG, Reutlingen, Germany), sense light through the eye's optics and subsequently stimulate retinal bipolar cells via ~1500 independent pixels to project visual signals to the brain. Because these devices are directly implanted beneath the fovea, they potentially harness the full benefit of eye movements to scan scenes and fixate objects. However, so far, the oculomotor behavior of patients using subretinal implants has not been characterized. Here, we tracked eye movements in two blind patients seeing with a subretinal implant, and we compared them to those of three healthy controls. We presented bright geometric shapes on a dark background, and we asked the patients to report seeing them or not. We found that once the patients visually localized the shapes, they fixated well and exhibited classic oculomotor fixational patterns, including the generation of microsaccades and ocular drifts. Further, we found that a reduced frequency of saccades and microsaccades was correlated with loss of visibility. Last, but not least, gaze location corresponded to the location of the stimulus, and shape and size aspects of the viewed stimulus were reflected by the direction and size of saccades. Our results pave the way for future use of eye tracking in subretinal implant patients, not only to understand their oculomotor behavior, but also to design oculomotor training strategies that can help improve their quality of life. |
K C Hamborg; M Bruns; F Ollermann; K Kaspar The effect of banner animation on fixation behavior and recall performance in search tasks Journal Article Computers in Human Behavior, 28 (2), pp. 576–582, 2012. @article{Hamborg2012, title = {The effect of banner animation on fixation behavior and recall performance in search tasks}, author = {K C Hamborg and M Bruns and F Ollermann and K Kaspar}, doi = {10.1016/j.chb.2011.11.003}, year = {2012}, date = {2012-01-01}, journal = {Computers in Human Behavior}, volume = {28}, number = {2}, pages = {576--582}, publisher = {Elsevier Ltd}, abstract = {Previous findings suggested that banner ads have little or no impact on perceptual behavior and memory performance in search tasks, but only in browsing paradigms. This assumption is not supported by the present eye-tracking study. It investigates whether task-related selective attention is disrupted depending on the animation intensity of banner ads when users are in a search mode as well as the impact of banner animation on perceptual and memory performance. We find that fixation frequency on banners increases with animation intensity. Moreover, a specific temporal course of fixation frequency on banners could be observed. However, the duration of fixations on a banner is independent of its animation intensity. Results also reveal that animation enhances the recall performance of banner content. The subject of advertisement, the position of the banner as well as writings and colors are recalled better when the banner is animated in contrast to a non-animated banner, whereby the animation intensity has no impact on banner related recall performance. Importantly, the performance in the actual information search task is not affected by banner animation. Moreover, animation intensity does not affect subjects' attitude towards the banner ad.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Previous findings suggested that banner ads have little or no impact on perceptual behavior and memory performance in search tasks, but only in browsing paradigms. This assumption is not supported by the present eye-tracking study. It investigates whether task-related selective attention is disrupted depending on the animation intensity of banner ads when users are in a search mode as well as the impact of banner animation on perceptual and memory performance. We find that fixation frequency on banners increases with animation intensity. Moreover, a specific temporal course of fixation frequency on banners could be observed. However, the duration of fixations on a banner is independent of its animation intensity. Results also reveal that animation enhances the recall performance of banner content. The subject of advertisement, the position of the banner as well as writings and colors are recalled better when the banner is animated in contrast to a non-animated banner, whereby the animation intensity has no impact on banner related recall performance. Importantly, the performance in the actual information search task is not affected by banner animation. Moreover, animation intensity does not affect subjects' attitude towards the banner ad. |
David J Hancock; Diane M Ste-Marie Gaze behaviors and decision making accuracy of higher- and lower-level ice hockey referees Journal Article Psychology of Sport and Exercise, 14 (1), pp. 66–71, 2013. @article{Hancock2013, title = {Gaze behaviors and decision making accuracy of higher- and lower-level ice hockey referees}, author = {David J Hancock and Diane M Ste-Marie}, doi = {dx.doi.org/10.1016/j.psychsport.2012.08.002}, year = {2013}, date = {2013-01-01}, journal = {Psychology of Sport and Exercise}, volume = {14}, number = {1}, pages = {66--71}, publisher = {Elsevier Ltd}, abstract = {Background: Gaze behaviors are often studied in athletes, but infrequently for sport officials. There is a need to better understand gaze behavior in refereeing in order to improve training and education related to visual search patterns, which have been argued to be related to decision making (Abernethy & Russell, 1987a). Objective: To examine gaze behaviors, decision accuracy, and decision sensitivity (using signal detection analysis) of ice hockey referees of varying skill levels in a laboratory setting. Design: Using an experimental design, we conducted multiple t-tests. Method: Higher-level (N = 15) and lower-level ice hockey referees (N = 15) wore a head-mounted eye movement recorder and made penalty/no penalty decisions related to ice hockey video clips on a computer screen. We recorded gaze behaviors, decision accuracy, and decision sensitivity for each participant. Results: Results of the t-tests indicated no group differences in gaze behaviors; however, higher-level referees made significantly more accurate decisions (both accuracy and sensitivity) than lower-level referees. Conclusion: Higher-level ice hockey referees are superior to lower-level referees on decision making, but referees do not differ on gaze behaviors. Possibly, higher-level referees process relevant decision making information more effectively.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: Gaze behaviors are often studied in athletes, but infrequently for sport officials. There is a need to better understand gaze behavior in refereeing in order to improve training and education related to visual search patterns, which have been argued to be related to decision making (Abernethy & Russell, 1987a). Objective: To examine gaze behaviors, decision accuracy, and decision sensitivity (using signal detection analysis) of ice hockey referees of varying skill levels in a laboratory setting. Design: Using an experimental design, we conducted multiple t-tests. Method: Higher-level (N = 15) and lower-level ice hockey referees (N = 15) wore a head-mounted eye movement recorder and made penalty/no penalty decisions related to ice hockey video clips on a computer screen. We recorded gaze behaviors, decision accuracy, and decision sensitivity for each participant. Results: Results of the t-tests indicated no group differences in gaze behaviors; however, higher-level referees made significantly more accurate decisions (both accuracy and sensitivity) than lower-level referees. Conclusion: Higher-level ice hockey referees are superior to lower-level referees on decision making, but referees do not differ on gaze behaviors. Possibly, higher-level referees process relevant decision making information more effectively. |
Jessica Hanley; David Warren; Natalie Glass; Daniel Tranel; Matthew Karam; Joseph Buckwalter Visual interpretation of plain radiographs in orthopaedics using eye-tracking technology Journal Article The Iowa Orthopaedic Journal, 37 , pp. 225–231, 2017. @article{Hanley2017, title = {Visual interpretation of plain radiographs in orthopaedics using eye-tracking technology}, author = {Jessica Hanley and David Warren and Natalie Glass and Daniel Tranel and Matthew Karam and Joseph Buckwalter}, year = {2017}, date = {2017-01-01}, journal = {The Iowa Orthopaedic Journal}, volume = {37}, pages = {225--231}, abstract = {BACKGROUND: Despite the importance of radiographic interpretation in orthopaedics, there not a clear understanding of the specific visual strategies used while analyzing a plain film. Eyetracking technology allows for the objective study of eye movements while performing a dynamic task, such as reading X-rays. Our study looks to elucidate objective differences in image interpretation between novice and experienced orthopaedic trainees using this novel technology. METHODS: Novice and experienced orthopaedic trainees (N=23) were asked to interpret AP pelvis films, searching for unilateral acetabular fractures while eye-movements were assessed for pattern of gaze, fixation on regions of interest, and time of fixation at regions of interest. Participants were asked to label radiographs as "fractured" or "not fractured." If "fractured", the participant was asked to determine the fracture pattern. A control condition employed Ekman faces and participants judged gender and facial emotion. Data were analyzed for variation in eye movements between participants, accuracy of responses, and response time. RESULTS: Accuracy: There was no significant difference by level of training for accurately identifing fracture images (p=0.3255). There was a significant association between higher level of training and correctly identifying non-fractured images (p=0.0155); greater training was also associated with more success in identifying the correct Judet-Letournel classification (p=0.0029). Response Time: Greater training was associated with faster response times (p=0.0009 for fracture images and 0.0012 for non-fractured images). Fixation Duration: There was no correlation of average fixation duration with experience (p=0.9632). Regions of Interest (ROIs): More experience was associated with an average of two fewer fixated ROIs (p=0.0047). Number of Fixations: Increased experience was associated with fewer fixations overall (p=0.0007). CONCLUSIONS: Experience has a significant impact on both accuracy and efficiency in interpreting plain films. Greater training is associated with a shift toward a more efficient and thorough assessment of plain radiographs. Eyetracking is a useful descriptive tool in the setting of plain film interpretation. CLINICAL RELEVANCE: We propose further assessment of eye movements in larger populations of orthopaedic surgeons, including staff orthopaedists. Describing the differences between novice and expert interpretation may provide insight into ways to accelerate the learning process in young orthopaedists.}, keywords = {}, pubstate = {published}, tppubtype = {article} } BACKGROUND: Despite the importance of radiographic interpretation in orthopaedics, there not a clear understanding of the specific visual strategies used while analyzing a plain film. Eyetracking technology allows for the objective study of eye movements while performing a dynamic task, such as reading X-rays. Our study looks to elucidate objective differences in image interpretation between novice and experienced orthopaedic trainees using this novel technology. METHODS: Novice and experienced orthopaedic trainees (N=23) were asked to interpret AP pelvis films, searching for unilateral acetabular fractures while eye-movements were assessed for pattern of gaze, fixation on regions of interest, and time of fixation at regions of interest. Participants were asked to label radiographs as "fractured" or "not fractured." If "fractured", the participant was asked to determine the fracture pattern. A control condition employed Ekman faces and participants judged gender and facial emotion. Data were analyzed for variation in eye movements between participants, accuracy of responses, and response time. RESULTS: Accuracy: There was no significant difference by level of training for accurately identifing fracture images (p=0.3255). There was a significant association between higher level of training and correctly identifying non-fractured images (p=0.0155); greater training was also associated with more success in identifying the correct Judet-Letournel classification (p=0.0029). Response Time: Greater training was associated with faster response times (p=0.0009 for fracture images and 0.0012 for non-fractured images). Fixation Duration: There was no correlation of average fixation duration with experience (p=0.9632). Regions of Interest (ROIs): More experience was associated with an average of two fewer fixated ROIs (p=0.0047). Number of Fixations: Increased experience was associated with fewer fixations overall (p=0.0007). CONCLUSIONS: Experience has a significant impact on both accuracy and efficiency in interpreting plain films. Greater training is associated with a shift toward a more efficient and thorough assessment of plain radiographs. Eyetracking is a useful descriptive tool in the setting of plain film interpretation. CLINICAL RELEVANCE: We propose further assessment of eye movements in larger populations of orthopaedic surgeons, including staff orthopaedists. Describing the differences between novice and expert interpretation may provide insight into ways to accelerate the learning process in young orthopaedists. |
Alistair J Harvey; Wendy Kneller; Alison C Campbell The effects of alcohol intoxication on attention and memory for visual scenes. Journal Article Memory, 21 (8), pp. 969–980, 2013. @article{Harvey2013, title = {The effects of alcohol intoxication on attention and memory for visual scenes.}, author = {Alistair J Harvey and Wendy Kneller and Alison C Campbell}, doi = {10.1080/09658211.2013.770033}, year = {2013}, date = {2013-01-01}, journal = {Memory}, volume = {21}, number = {8}, pages = {969--980}, publisher = {Taylor & Francis}, abstract = {This study tests the claim that alcohol intoxication narrows the focus of visual attention on to the more salient features of a visual scene. A group of alcohol intoxicated and sober participants had their eye movements recorded as they encoded a photographic image featuring a central event of either high or low salience. All participants then recalled the details of the image the following day when sober. We sought to determine whether the alcohol group would pay less attention to the peripheral features of the encoded scene than their sober counterparts, whether this effect of attentional narrowing was stronger for the high-salience event than for the low-salience event, and whether it would lead to a corresponding deficit in peripheral recall. Alcohol was found to narrow the focus of foveal attention to the central features of both images but did not facilitate recall from this region. It also reduced the overall amount of information accurately recalled from each scene. These findings demonstrate that the concept of alcohol myopia originally posited to explain the social consequences of intoxication (Steele & Josephs, 1990) may be extended to explain the relative neglect of peripheral information during the processing of visual scenes.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This study tests the claim that alcohol intoxication narrows the focus of visual attention on to the more salient features of a visual scene. A group of alcohol intoxicated and sober participants had their eye movements recorded as they encoded a photographic image featuring a central event of either high or low salience. All participants then recalled the details of the image the following day when sober. We sought to determine whether the alcohol group would pay less attention to the peripheral features of the encoded scene than their sober counterparts, whether this effect of attentional narrowing was stronger for the high-salience event than for the low-salience event, and whether it would lead to a corresponding deficit in peripheral recall. Alcohol was found to narrow the focus of foveal attention to the central features of both images but did not facilitate recall from this region. It also reduced the overall amount of information accurately recalled from each scene. These findings demonstrate that the concept of alcohol myopia originally posited to explain the social consequences of intoxication (Steele & Josephs, 1990) may be extended to explain the relative neglect of peripheral information during the processing of visual scenes. |
Lisena Hasanaj; Sujata P Thawani; Nikki Webb; Julia D Drattell; Liliana Serrano; Rachel C Nolan; Jenelle Raynowska; Todd E Hudson; John-Ross Ross Rizzo; Weiwei Dai; Bryan McComb; Judith D Goldberg; Janet C Rucker; Steven L Galetta; Laura J Balcer Rapid number naming and quantitative eye movements may reflect contact sport exposure in a collegiate ice hockey cohort Journal Article Journal of Neuro-Ophthalmology, 38 (1), pp. 24–29, 2018. @article{Hasanaj2018, title = {Rapid number naming and quantitative eye movements may reflect contact sport exposure in a collegiate ice hockey cohort}, author = {Lisena Hasanaj and Sujata P Thawani and Nikki Webb and Julia D Drattell and Liliana Serrano and Rachel C Nolan and Jenelle Raynowska and Todd E Hudson and John-Ross Ross Rizzo and Weiwei Dai and Bryan McComb and Judith D Goldberg and Janet C Rucker and Steven L Galetta and Laura J Balcer}, doi = {10.1097/wno.0000000000000533}, year = {2018}, date = {2018-01-01}, journal = {Journal of Neuro-Ophthalmology}, volume = {38}, number = {1}, pages = {24--29}, abstract = {Objective: We determined the relation of rapid number naming time scores on the King-Devick (K-D) test to video-oculographic eye movement performance during pre-season baseline assessments in a collegiate ice hockey team cohort. Background: The K-D test is a reliable visual performance measure that is a sensitive sideline indicator of concussion when time scores worsen (lengthen) from pre-season baseline. Methods: Athletes from collegiate ice hockey team received pre-season baseline testing as part of an ongoing study of rapid sideline/ rinkside performance measures for concussion. These included the K-D test (spiral bound cards and tablet computer versions). Participants also performed a laboratory-based version of the K-D test with simultaneous infrared-based video-oculographic recordings using EyeLink 1000+. This allowed measurement of temporal and spatial characteristics of eye movements, including saccade velocity, duration and inter-saccadic intervals. Results: Among 13 male athletes, aged 18 to 23 years (mean 20.5+/-1.6 years), prolongation of the inter-saccadic interval (ISI, a combined measure of saccade latency and fixation duration) was the eye movement measure most associated with slower baseline KD scores (mean 38.2+/-6.2 seconds}, keywords = {}, pubstate = {published}, tppubtype = {article} } Objective: We determined the relation of rapid number naming time scores on the King-Devick (K-D) test to video-oculographic eye movement performance during pre-season baseline assessments in a collegiate ice hockey team cohort. Background: The K-D test is a reliable visual performance measure that is a sensitive sideline indicator of concussion when time scores worsen (lengthen) from pre-season baseline. Methods: Athletes from collegiate ice hockey team received pre-season baseline testing as part of an ongoing study of rapid sideline/ rinkside performance measures for concussion. These included the K-D test (spiral bound cards and tablet computer versions). Participants also performed a laboratory-based version of the K-D test with simultaneous infrared-based video-oculographic recordings using EyeLink 1000+. This allowed measurement of temporal and spatial characteristics of eye movements, including saccade velocity, duration and inter-saccadic intervals. Results: Among 13 male athletes, aged 18 to 23 years (mean 20.5+/-1.6 years), prolongation of the inter-saccadic interval (ISI, a combined measure of saccade latency and fixation duration) was the eye movement measure most associated with slower baseline KD scores (mean 38.2+/-6.2 seconds |
Sogand Hasanzadeh; Behzad Esmaeili; Michael D Dodd Journal of Management in Engineering, 33 (5), pp. 1–17, 2017. @article{Hasanzadeh2017a, title = {Measuring the impacts of safety knowledge on construction workers' attentional allocation and hazard detection using remote eye-tracking technology}, author = {Sogand Hasanzadeh and Behzad Esmaeili and Michael D Dodd}, doi = {10.1061/(ASCE)ME.1943-5479.0000526}, year = {2017}, date = {2017-01-01}, journal = {Journal of Management in Engineering}, volume = {33}, number = {5}, pages = {1--17}, abstract = {Although several studies have highlighted the importance of attention in reducing the number of injuries in the construction industry, few have attempted to empirically measure the attention of construction workers. One technique that can be used to measure worker attention is eye tracking, which is widely accepted as the most direct and continuous measure of attention because where one looks is highly correlated with where one is focusing his or her attention. Thus, with the fundamental objective of measuring the impacts of safety knowledge (specifically, training, work experience, and injury exposure) on construction workers' attentional allocation, this study demonstrates the application of eye tracking to the realm of construction safety practices. To achieve this objective, a laboratory experiment was designed in which participants identified safety hazards presented in 35 construction site images ordered randomly, each of which showed multiple hazards varying in safety risk. During the experiment, the eye movements of 27 construction workers were recorded using a head-mounted EyeLink II system. The impact of worker safety knowledge in terms of training, work experience, and injury exposure (independent variables) on eye-tracking metrics (dependent variables) was then assessed by implementing numerous permutation simulations. The results show that tacit safety knowledge acquired from work experience and injury exposure can significantly improve construction workers' hazard detection and visual search strategies. The results also demonstrate that (1) there is minimal difference, with or without the Occupational Safety and Health Administration 10-h certificate, in workers' search strategies and attentional patterns while exposed to or seeing hazardous situations; (2) relative to less experienced workers (textless5 years), more experienced workers (textgreater10 years) need less processing time and deploy more frequent short fixations on hazardous areas to maintain situational awareness of the environment; and (3) injury exposure significantly impacts a worker's visual search strategy and attentional allocation. In sum, practical safety knowledge and judgment on a jobsite requires the interaction of both tacit and explicit knowledge gained through work experience, injury exposure, and interactive safety training. This study significantly contributes to the literature by demonstrating the potential application of eye-tracking technology in studying the attentional allocation of construction workers. Regarding practice, the results of the study show that eye tracking can be used to improve worker training and preparedness, which will yield safer working conditions, detect at-risk workers, and improve the effectiveness of safety-training programs.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Although several studies have highlighted the importance of attention in reducing the number of injuries in the construction industry, few have attempted to empirically measure the attention of construction workers. One technique that can be used to measure worker attention is eye tracking, which is widely accepted as the most direct and continuous measure of attention because where one looks is highly correlated with where one is focusing his or her attention. Thus, with the fundamental objective of measuring the impacts of safety knowledge (specifically, training, work experience, and injury exposure) on construction workers' attentional allocation, this study demonstrates the application of eye tracking to the realm of construction safety practices. To achieve this objective, a laboratory experiment was designed in which participants identified safety hazards presented in 35 construction site images ordered randomly, each of which showed multiple hazards varying in safety risk. During the experiment, the eye movements of 27 construction workers were recorded using a head-mounted EyeLink II system. The impact of worker safety knowledge in terms of training, work experience, and injury exposure (independent variables) on eye-tracking metrics (dependent variables) was then assessed by implementing numerous permutation simulations. The results show that tacit safety knowledge acquired from work experience and injury exposure can significantly improve construction workers' hazard detection and visual search strategies. The results also demonstrate that (1) there is minimal difference, with or without the Occupational Safety and Health Administration 10-h certificate, in workers' search strategies and attentional patterns while exposed to or seeing hazardous situations; (2) relative to less experienced workers (textless5 years), more experienced workers (textgreater10 years) need less processing time and deploy more frequent short fixations on hazardous areas to maintain situational awareness of the environment; and (3) injury exposure significantly impacts a worker's visual search strategy and attentional allocation. In sum, practical safety knowledge and judgment on a jobsite requires the interaction of both tacit and explicit knowledge gained through work experience, injury exposure, and interactive safety training. This study significantly contributes to the literature by demonstrating the potential application of eye-tracking technology in studying the attentional allocation of construction workers. Regarding practice, the results of the study show that eye tracking can be used to improve worker training and preparedness, which will yield safer working conditions, detect at-risk workers, and improve the effectiveness of safety-training programs. |
Sogand Hasanzadeh; Behzad Esmaeili; Michael D Dodd Impact of construction workers' hazard identification skills on their visual attention Journal Article Journal of Construction Engineering and Management, 143 (10), pp. 1–16, 2017. @article{Hasanzadeh2017b, title = {Impact of construction workers' hazard identification skills on their visual attention}, author = {Sogand Hasanzadeh and Behzad Esmaeili and Michael D Dodd}, doi = {10.1061/(ASCE)CO.1943-7862.0001373}, year = {2017}, date = {2017-01-01}, journal = {Journal of Construction Engineering and Management}, volume = {143}, number = {10}, pages = {1--16}, abstract = {Eye-movement metrics have been shown to correlate with attention and, therefore, represent a means of identifying and analyzing an individual's cognitive processes. Human errors--such as failure to identify a hazard--are often attributed to a worker's lack of attention. Piecemeal attempts have been made to investigate the potential of harnessing eye movements as predictors of human error (e.g., failure to identify a hazard) in the construction industry, although more attempts have investigated human error via subjective measurements. To address this knowledge gap, the present study harnessed eye-tracking technology to evaluate the impacts of workers' hazard-identification skills on their attentional distributions and visual search strategies. To achieve this objective, an experiment was designed in which the eye movements of 31 construction workers were tracked while they searched for hazards in 35 randomly ordered construction scenario images. Workers were then divided into three groups on the basis of their hazard identification performance. Three fixation-related metrics--fixation count, dwell-time percentage, and run count--were analyzed during the eye-tracking experiment for each group (low, medium, and high hazard-identification skills) across various types of hazards. Then, multivariate ANOVA (MANOVA) was used to evaluate the impact of workers' hazard-identification skills on their visual attention. To further investigate the effect of hazard identification skills on the dependent variables (eye movement metrics), two distinct processes followed: separate ANOVAs on each of the dependent variables, and a discriminant function analysis. The analyses indicated that hazard identification skills significantly impact workers' visual search strategies: workers with higher hazard-identification skills had lower dwell-time percentages on ladder-related hazards; higher fixation counts on fall-to-lower-level hazards; and higher fixation counts and run counts on fall-protection systems, struck-by, housekeeping, and all hazardous areas combined. Among the eye-movement metrics studied, fixation count had the largest standardized coefficient in all canonical discriminant functions, which implies that this eye-movement metric uniquely discriminates workers with high hazard-identification skills and at-risk workers. Because discriminant function analysis is similar to regression, discriminant function (linear combinations of eye-movement metrics) can be used to predict workers' hazard-identification capabilities. In conclusion, this study provides a proof of concept that certain eye- movement metrics are predictive indicators of human error due to attentional failure. These outcomes stemmed from a laboratory setting, and, foreseeably, safety managers in the future will be able to use these findings to identify at-risk construction workers, pinpoint required safety training, measure training effectiveness, and eventually improve future personal protective equipment to measure construction workers' situation awareness in real time.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Eye-movement metrics have been shown to correlate with attention and, therefore, represent a means of identifying and analyzing an individual's cognitive processes. Human errors--such as failure to identify a hazard--are often attributed to a worker's lack of attention. Piecemeal attempts have been made to investigate the potential of harnessing eye movements as predictors of human error (e.g., failure to identify a hazard) in the construction industry, although more attempts have investigated human error via subjective measurements. To address this knowledge gap, the present study harnessed eye-tracking technology to evaluate the impacts of workers' hazard-identification skills on their attentional distributions and visual search strategies. To achieve this objective, an experiment was designed in which the eye movements of 31 construction workers were tracked while they searched for hazards in 35 randomly ordered construction scenario images. Workers were then divided into three groups on the basis of their hazard identification performance. Three fixation-related metrics--fixation count, dwell-time percentage, and run count--were analyzed during the eye-tracking experiment for each group (low, medium, and high hazard-identification skills) across various types of hazards. Then, multivariate ANOVA (MANOVA) was used to evaluate the impact of workers' hazard-identification skills on their visual attention. To further investigate the effect of hazard identification skills on the dependent variables (eye movement metrics), two distinct processes followed: separate ANOVAs on each of the dependent variables, and a discriminant function analysis. The analyses indicated that hazard identification skills significantly impact workers' visual search strategies: workers with higher hazard-identification skills had lower dwell-time percentages on ladder-related hazards; higher fixation counts on fall-to-lower-level hazards; and higher fixation counts and run counts on fall-protection systems, struck-by, housekeeping, and all hazardous areas combined. Among the eye-movement metrics studied, fixation count had the largest standardized coefficient in all canonical discriminant functions, which implies that this eye-movement metric uniquely discriminates workers with high hazard-identification skills and at-risk workers. Because discriminant function analysis is similar to regression, discriminant function (linear combinations of eye-movement metrics) can be used to predict workers' hazard-identification capabilities. In conclusion, this study provides a proof of concept that certain eye- movement metrics are predictive indicators of human error due to attentional failure. These outcomes stemmed from a laboratory setting, and, foreseeably, safety managers in the future will be able to use these findings to identify at-risk construction workers, pinpoint required safety training, measure training effectiveness, and eventually improve future personal protective equipment to measure construction workers' situation awareness in real time. |
Claire Louise Heard; Tim Rakow; Tom Foulsham Understanding the effect of information presentation order and orientation on information search and treatment evaluation Journal Article Medical Decision Making, 38 (6), pp. 646–657, 2018. @article{Heard2018, title = {Understanding the effect of information presentation order and orientation on information search and treatment evaluation}, author = {Claire Louise Heard and Tim Rakow and Tom Foulsham}, doi = {10.1177/0272989X18785356}, year = {2018}, date = {2018-01-01}, journal = {Medical Decision Making}, volume = {38}, number = {6}, pages = {646--657}, abstract = {Background. Past research finds that treatment evaluations are more negative when risks are presented after benefits. This study investigates this order effect: manipulating tabular orientation and order of risk–benefit information, and examining information search order and gaze duration via eye-tracking. Design. 108 (Study 1) and 44 (Study 2) participants viewed information about treatment risks and benefits, in either a horizontal (left-right) or vertical (above- below) orientation, with the benefits or risks presented first (left side or at top). For 4 scenarios, participants answered 6 treatment evaluation questions (1–7 scales) that were combined into overall evaluation scores. In addi- tion, Study 2 collected eye-tracking data during the benefit–risk presentation. Results. Participants tended to read one set of information (i.e., all risks or all benefits) before transitioning to the other. Analysis of order of fixations showed this tendency was stronger in the vertical (standardized mean rank difference further from 0}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background. Past research finds that treatment evaluations are more negative when risks are presented after benefits. This study investigates this order effect: manipulating tabular orientation and order of risk–benefit information, and examining information search order and gaze duration via eye-tracking. Design. 108 (Study 1) and 44 (Study 2) participants viewed information about treatment risks and benefits, in either a horizontal (left-right) or vertical (above- below) orientation, with the benefits or risks presented first (left side or at top). For 4 scenarios, participants answered 6 treatment evaluation questions (1–7 scales) that were combined into overall evaluation scores. In addi- tion, Study 2 collected eye-tracking data during the benefit–risk presentation. Results. Participants tended to read one set of information (i.e., all risks or all benefits) before transitioning to the other. Analysis of order of fixations showed this tendency was stronger in the vertical (standardized mean rank difference further from 0 |
Matthew Heath; Erin Shellington; Sam Titheridge; Dawn P Gill; Robert J Petrella Journal of Alzheimer's Disease, 56 (1), pp. 167–183, 2017. @article{Heath2017, title = {A 24-week multi-modality exercise program improves executive control in older adults with a self-reported cognitive complaint: Evidence from the antisaccade task}, author = {Matthew Heath and Erin Shellington and Sam Titheridge and Dawn P Gill and Robert J Petrella}, doi = {10.3233/JAD-160627}, year = {2017}, date = {2017-01-01}, journal = {Journal of Alzheimer's Disease}, volume = {56}, number = {1}, pages = {167--183}, abstract = {Exercise programs involving aerobic and resistance training (i.e., multiple-modality) have shown promise in improving cognition and executive control in older adults at risk, or experiencing, cognitive decline. It is, however, unclear whether cognitive training within a multiple-modality program elicits an additive benefit to executive/cognitive processes. This is an important question to resolve in order to identify optimal training programs that delay, or ameliorate, executive deficits in persons at risk for further cognitive decline. In the present study, individuals with a self-reported cognitive complaint (SCC) participated in a 24-week multiple-modality (i.e., the M2 group) exercise intervention program. In addition, a separate group of individuals with a SCC completed the same aerobic and resistance training as the M2 group but also completed a cognitive-based stepping task (i.e., multiple-modality, mind-motor intervention: M4 group). Notably, pre- and post-intervention executive control was examined via the antisaccade task (i.e., eye movement mirror-symmetrical to a target). Antisaccades are an ideal tool for the study of individuals with subtle executive deficits because of its hands- and language-free nature and because the task's neural mechanisms are linked to neuropathology in cognitive decline (i.e., prefrontal cortex). Results showed that M2 and M4 group antisaccade reaction times reliably decreased from pre- to post-intervention and the magnitude of the decrease was consistent across groups. Thus, multi-modality exercise training improved executive performance in persons with a SCC independent of mind-motor training. Accordingly, we propose that multiple-modality training provides a sufficient intervention to improve executive control in persons with a SCC.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Exercise programs involving aerobic and resistance training (i.e., multiple-modality) have shown promise in improving cognition and executive control in older adults at risk, or experiencing, cognitive decline. It is, however, unclear whether cognitive training within a multiple-modality program elicits an additive benefit to executive/cognitive processes. This is an important question to resolve in order to identify optimal training programs that delay, or ameliorate, executive deficits in persons at risk for further cognitive decline. In the present study, individuals with a self-reported cognitive complaint (SCC) participated in a 24-week multiple-modality (i.e., the M2 group) exercise intervention program. In addition, a separate group of individuals with a SCC completed the same aerobic and resistance training as the M2 group but also completed a cognitive-based stepping task (i.e., multiple-modality, mind-motor intervention: M4 group). Notably, pre- and post-intervention executive control was examined via the antisaccade task (i.e., eye movement mirror-symmetrical to a target). Antisaccades are an ideal tool for the study of individuals with subtle executive deficits because of its hands- and language-free nature and because the task's neural mechanisms are linked to neuropathology in cognitive decline (i.e., prefrontal cortex). Results showed that M2 and M4 group antisaccade reaction times reliably decreased from pre- to post-intervention and the magnitude of the decrease was consistent across groups. Thus, multi-modality exercise training improved executive performance in persons with a SCC independent of mind-motor training. Accordingly, we propose that multiple-modality training provides a sufficient intervention to improve executive control in persons with a SCC. |
Kristin J Heaton; Alexis L Maule; Jun Maruta; Elisabeth M Kryskow; Jamshid Ghajar Attention and visual tracking degradation during acute sleep deprivation in a military sample Journal Article Aviation Space and Environmental Medicine, 85 (5), pp. 497–503, 2014. @article{Heaton2014, title = {Attention and visual tracking degradation during acute sleep deprivation in a military sample}, author = {Kristin J Heaton and Alexis L Maule and Jun Maruta and Elisabeth M Kryskow and Jamshid Ghajar}, doi = {10.3357/ASEM.3882.2014}, year = {2014}, date = {2014-01-01}, journal = {Aviation Space and Environmental Medicine}, volume = {85}, number = {5}, pages = {497--503}, abstract = {Background: Fatigue due to sleep restriction places individuals at elevated risk for accidents, degraded health, and impaired physical and mental performance. Early detection of fatigue-related performance decrements is an important component of injury prevention and can help to ensure optimal performance and mission readiness. This study used a predictive visual tracking task and a computer-based measure of attention to characterize fatigue-related attention decrements in healthy Army personnel during acute sleep deprivation. Methods: Serving as subjects in this laboratory-based study were 87 male and female service members between the ages of 18 and 50 with no history of brain injury with loss of consciousness, substance abuse, or significant psychiatric or neurologic diagnoses. Subjects underwent 26 h of sleep deprivation, during which eye movement measures from a continuous circular visual tracking task and attention measures (reaction time, accuracy) from the Attention Network Test (ANT) were collected at baseline, 20 h awake, and between 24 to 26 h awake. Results: Increases in the variability of gaze positional errors (46-47%), as well as reaction time-based ANT measures (9-65%), were observed across 26 h of sleep deprivation. Accuracy of ANT responses declined across this same period (11%). Discussion: Performance measures of predictive visual tracking accurately reflect impaired attention due to acute sleep deprivation and provide a promising approach for assessing readiness in personnel serving in diverse occupational areas, including flight and ground support crews.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: Fatigue due to sleep restriction places individuals at elevated risk for accidents, degraded health, and impaired physical and mental performance. Early detection of fatigue-related performance decrements is an important component of injury prevention and can help to ensure optimal performance and mission readiness. This study used a predictive visual tracking task and a computer-based measure of attention to characterize fatigue-related attention decrements in healthy Army personnel during acute sleep deprivation. Methods: Serving as subjects in this laboratory-based study were 87 male and female service members between the ages of 18 and 50 with no history of brain injury with loss of consciousness, substance abuse, or significant psychiatric or neurologic diagnoses. Subjects underwent 26 h of sleep deprivation, during which eye movement measures from a continuous circular visual tracking task and attention measures (reaction time, accuracy) from the Attention Network Test (ANT) were collected at baseline, 20 h awake, and between 24 to 26 h awake. Results: Increases in the variability of gaze positional errors (46-47%), as well as reaction time-based ANT measures (9-65%), were observed across 26 h of sleep deprivation. Accuracy of ANT responses declined across this same period (11%). Discussion: Performance measures of predictive visual tracking accurately reflect impaired attention due to acute sleep deprivation and provide a promising approach for assessing readiness in personnel serving in diverse occupational areas, including flight and ground support crews. |
Mary Hegarty; Matt S Canham; Sara I Fabrikant Thinking about the weather: How display salience and knowledge affect performance in a graphic inference task Journal Article Journal of Experimental Psychology: Learning, Memory, and Cognition, 36 (1), pp. 37–53, 2010. @article{Hegarty2010, title = {Thinking about the weather: How display salience and knowledge affect performance in a graphic inference task}, author = {Mary Hegarty and Matt S Canham and Sara I Fabrikant}, doi = {10.1037/a0017683}, year = {2010}, date = {2010-01-01}, journal = {Journal of Experimental Psychology: Learning, Memory, and Cognition}, volume = {36}, number = {1}, pages = {37--53}, abstract = {Three experiments examined how bottom-up and top-down processes interact when people view and make inferences from complex visual displays (weather maps). Bottom-up effects of display design were investigated by manipulating the relative visual salience of task-relevant and task-irrelevant information across different maps. Top-down effects of domain knowledge were investigated by examining performance and eye fixations before and after participants learned relevant meteorological principles. Map design and knowledge interacted such that salience had no effect on performance before participants learned the meteorological principles; however, after learning, participants were more accurate if they viewed maps that made task-relevant information more visually salient. Effects of display design on task performance were somewhat dissociated from effects of display design on eye fixations. The results support a model in which eye fixations are directed primarily by top-down factors (task and domain knowledge). They suggest that good display design facilitates performance not just by guiding where viewers look in a complex display but also by facilitating processing of the visual features that represent task-relevant information at a given display location.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Three experiments examined how bottom-up and top-down processes interact when people view and make inferences from complex visual displays (weather maps). Bottom-up effects of display design were investigated by manipulating the relative visual salience of task-relevant and task-irrelevant information across different maps. Top-down effects of domain knowledge were investigated by examining performance and eye fixations before and after participants learned relevant meteorological principles. Map design and knowledge interacted such that salience had no effect on performance before participants learned the meteorological principles; however, after learning, participants were more accurate if they viewed maps that made task-relevant information more visually salient. Effects of display design on task performance were somewhat dissociated from effects of display design on eye fixations. The results support a model in which eye fixations are directed primarily by top-down factors (task and domain knowledge). They suggest that good display design facilitates performance not just by guiding where viewers look in a complex display but also by facilitating processing of the visual features that represent task-relevant information at a given display location. |
Mary Hegarty; Harvey S Smallman; Andrew T Stull Choosing and using geospatial displays: Effects of design on performance and metacognition Journal Article Journal of Experimental Psychology: Applied, 18 (1), pp. 1–17, 2012. @article{Hegarty2012, title = {Choosing and using geospatial displays: Effects of design on performance and metacognition}, author = {Mary Hegarty and Harvey S Smallman and Andrew T Stull}, doi = {10.1037/a0026625}, year = {2012}, date = {2012-01-01}, journal = {Journal of Experimental Psychology: Applied}, volume = {18}, number = {1}, pages = {1--17}, abstract = {Interactive display systems give users flexibility to tailor their visual displays to different tasks and situations. However, in order for such flexibility to be beneficial, users need to understand how to tailor displays to different tasks (to possess “metarepresentational competence”). Recent research suggests that people may desire more complex and realistic displays than are most effective (Smallman & St. John, 2005). In Experiment 1, undergraduate students were tested on a comprehension task with geospatial displays (weather maps) that varied in the number of extraneous variables displayed. Their metacognitive judgments about the relative effectiveness of the displays were also solicited. Extraneous variables slowed response time and increased errors, but participants favored complex maps that looked more realistic about one third of the time. In Experiment 2, the eye fixations of undergraduate students were monitored as they performed the comprehension task. Complex maps that looked more realistic led to more eye fixations on both task-relevant and task-irrelevant regions of the displays. Experiment 3 compared performance of experienced meteorologists and undergraduate students on the comprehension and metacognitive tasks. Meteorologists were as likely as undergraduate students to prefer geographically complex (realistic) displays and more likely than undergraduates to opt for displays that added extraneous weather variables. However, meteorologists were also slower and less accurate with complex than with simple displays. This work highlights the importance of empirically testing principles of visual display design and suggests some limits to metarepresentational competence.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Interactive display systems give users flexibility to tailor their visual displays to different tasks and situations. However, in order for such flexibility to be beneficial, users need to understand how to tailor displays to different tasks (to possess “metarepresentational competence”). Recent research suggests that people may desire more complex and realistic displays than are most effective (Smallman & St. John, 2005). In Experiment 1, undergraduate students were tested on a comprehension task with geospatial displays (weather maps) that varied in the number of extraneous variables displayed. Their metacognitive judgments about the relative effectiveness of the displays were also solicited. Extraneous variables slowed response time and increased errors, but participants favored complex maps that looked more realistic about one third of the time. In Experiment 2, the eye fixations of undergraduate students were monitored as they performed the comprehension task. Complex maps that looked more realistic led to more eye fixations on both task-relevant and task-irrelevant regions of the displays. Experiment 3 compared performance of experienced meteorologists and undergraduate students on the comprehension and metacognitive tasks. Meteorologists were as likely as undergraduate students to prefer geographically complex (realistic) displays and more likely than undergraduates to opt for displays that added extraneous weather variables. However, meteorologists were also slower and less accurate with complex than with simple displays. This work highlights the importance of empirically testing principles of visual display design and suggests some limits to metarepresentational competence. |
Benedetta Heimler; Francesco Pavani; Mieke Donk; Wieske van Zoest Stimulus-and goal-driven control of eye movements: Action videogame players are faster but not better Journal Article Attention, Perception, & Psychophysics, 76 (8), pp. 2398–2412, 2014. @article{Heimler2014, title = {Stimulus-and goal-driven control of eye movements: Action videogame players are faster but not better}, author = {Benedetta Heimler and Francesco Pavani and Mieke Donk and Wieske van Zoest}, doi = {10.3758/s13414-014-0736-x}, year = {2014}, date = {2014-01-01}, journal = {Attention, Perception, & Psychophysics}, volume = {76}, number = {8}, pages = {2398--2412}, abstract = {Action videogame players (AVGPs) have been shown to outperform nongamers (NVGPs) in covert visual attention tasks. These advantages have been attributed to improved top-down control in this population. The time course of visual selection, which permits researchers to highlight when top-down strategies start to control performance, has rarely been investigated in AVGPs. Here, we addressed specifically this issue through an oculomotor additional-singleton paradigm. Participants were instructed to make a saccadic eye movement to a unique orientation singleton. The target was presented among homogeneous nontargets and one additional orientation singleton that was more, equally, or less salient than the target. Saliency was manipulated in the color dimension. Our results showed similar patterns of performance for both AVGPs and NVGPs: Fast-initiated saccades were saliency-driven, whereas later-initiated saccades were more goal-driven. However, although AVGPs were faster than NVGPs, they were also less accurate. Importantly, a multinomial model applied to the data revealed comparable underlying saliency-driven and goal-driven functions for the two groups. Taken together, the observed differences in performance are compatible with the presence of a lower decision bound for releasing saccades in AVGPs than in NVGPs, in the context of comparable temporal interplay between the underlying attentional mechanisms. In sum, the present findings show that in both AVGPs and NVGPs, the implementation of top-down control in visual selection takes time to come about, and they argue against the idea of a general enhancement of top-down control in AVGPs.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Action videogame players (AVGPs) have been shown to outperform nongamers (NVGPs) in covert visual attention tasks. These advantages have been attributed to improved top-down control in this population. The time course of visual selection, which permits researchers to highlight when top-down strategies start to control performance, has rarely been investigated in AVGPs. Here, we addressed specifically this issue through an oculomotor additional-singleton paradigm. Participants were instructed to make a saccadic eye movement to a unique orientation singleton. The target was presented among homogeneous nontargets and one additional orientation singleton that was more, equally, or less salient than the target. Saliency was manipulated in the color dimension. Our results showed similar patterns of performance for both AVGPs and NVGPs: Fast-initiated saccades were saliency-driven, whereas later-initiated saccades were more goal-driven. However, although AVGPs were faster than NVGPs, they were also less accurate. Importantly, a multinomial model applied to the data revealed comparable underlying saliency-driven and goal-driven functions for the two groups. Taken together, the observed differences in performance are compatible with the presence of a lower decision bound for releasing saccades in AVGPs than in NVGPs, in the context of comparable temporal interplay between the underlying attentional mechanisms. In sum, the present findings show that in both AVGPs and NVGPs, the implementation of top-down control in visual selection takes time to come about, and they argue against the idea of a general enhancement of top-down control in AVGPs. |
Jens R Helmert; Sebastian Pannasch; Boris M Velichkovsky Influences of dwell time and cursor control on the performance in gaze driven typing Journal Article Journal of Eye Movement Research, 2 (1), pp. 1–8, 2008. @article{Helmert2008, title = {Influences of dwell time and cursor control on the performance in gaze driven typing}, author = {Jens R Helmert and Sebastian Pannasch and Boris M Velichkovsky}, doi = {10.16910/jemr.2.4.3}, year = {2008}, date = {2008-01-01}, journal = {Journal of Eye Movement Research}, volume = {2}, number = {1}, pages = {1--8}, abstract = {In gaze controlled computer interfaces the dwell time is often used as selection criterion. But this solution comes along with several problems, especially in the temporal domain: Eye movement studies on scene perception could demonstrate that fixations of different durations serve different purposes and should therefore be differentiated. The use of dwell time for selection implies the need to distinguish intentional selections from merely per-ceptual processes, described as the Midas touch problem. Moreover, the feedback of the actual own eye position has not yet been addressed to systematic studies in the context of usability in gaze based computer interaction. We present research on the usability of a simple eye typing set up. Different dwell time and eye position feedback configurations were tested. Our results indicate that smoothing raw eye position and temporal delays in visual feedback enhance the system's functionality and usability. Best overall performance was obtained with a dwell time of 500 ms.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In gaze controlled computer interfaces the dwell time is often used as selection criterion. But this solution comes along with several problems, especially in the temporal domain: Eye movement studies on scene perception could demonstrate that fixations of different durations serve different purposes and should therefore be differentiated. The use of dwell time for selection implies the need to distinguish intentional selections from merely per-ceptual processes, described as the Midas touch problem. Moreover, the feedback of the actual own eye position has not yet been addressed to systematic studies in the context of usability in gaze based computer interaction. We present research on the usability of a simple eye typing set up. Different dwell time and eye position feedback configurations were tested. Our results indicate that smoothing raw eye position and temporal delays in visual feedback enhance the system's functionality and usability. Best overall performance was obtained with a dwell time of 500 ms. |
Constanze Hesse; Tristan T Nakagawa; Heiner Deubel Bimanual movement control is moderated by fixation strategies Journal Article Experimental Brain Research, 202 (4), pp. 837–850, 2010. @article{Hesse2010, title = {Bimanual movement control is moderated by fixation strategies}, author = {Constanze Hesse and Tristan T Nakagawa and Heiner Deubel}, doi = {10.1007/s00221-010-2189-3}, year = {2010}, date = {2010-01-01}, journal = {Experimental Brain Research}, volume = {202}, number = {4}, pages = {837--850}, abstract = {Our study examined the effects of performing a pointing movement with the left hand on the kinematics of a simultaneous grasping movement executed with the right hand. We were especially interested in the question of whether both movements can be controlled independently or whether interference effects occur. Since previous studies suggested that eye movements may play a crucial role in bimanual movement control, the effects of different fixation strategies were also studied. Human participants were either free to move their eyes (Experiment 1) or they had to fixate (Experiment 2) while doing the task. The results show that bimanual movement control differed fundamentally depending on the fixation condition: if free viewing was allowed, participants tended to perform the task sequentially, as reflected in grasping kinematics by a delayed grip opening and a poor adaptation of the grip to the object properties for the duration of the pointing movement. This behavior was accompanied by a serial fixation of the targets for the pointing and grasping movements. In contrast, when central fixation was required, both movements were performed fast and with no obvious interference effects. The results support the notion that bimanual movement control is moderated by fixation strategies. By default, participants seem to prefer a sequential behavior in which the eyes monitor what the hands are doing. However, when forced to fixate, they do surprisingly well in performing both movements in parallel.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Our study examined the effects of performing a pointing movement with the left hand on the kinematics of a simultaneous grasping movement executed with the right hand. We were especially interested in the question of whether both movements can be controlled independently or whether interference effects occur. Since previous studies suggested that eye movements may play a crucial role in bimanual movement control, the effects of different fixation strategies were also studied. Human participants were either free to move their eyes (Experiment 1) or they had to fixate (Experiment 2) while doing the task. The results show that bimanual movement control differed fundamentally depending on the fixation condition: if free viewing was allowed, participants tended to perform the task sequentially, as reflected in grasping kinematics by a delayed grip opening and a poor adaptation of the grip to the object properties for the duration of the pointing movement. This behavior was accompanied by a serial fixation of the targets for the pointing and grasping movements. In contrast, when central fixation was required, both movements were performed fast and with no obvious interference effects. The results support the notion that bimanual movement control is moderated by fixation strategies. By default, participants seem to prefer a sequential behavior in which the eyes monitor what the hands are doing. However, when forced to fixate, they do surprisingly well in performing both movements in parallel. |
Corey D Holland; Oleg V Komogortsev Complex eye movement pattern biometrics: The effects of environment and stimulus Journal Article IEEE Transactions on Information Forensics and Security, 8 (12), pp. 2115–2126, 2013. @article{Holland2013, title = {Complex eye movement pattern biometrics: The effects of environment and stimulus}, author = {Corey D Holland and Oleg V Komogortsev}, doi = {10.1109/TIFS.2013.2285884}, year = {2013}, date = {2013-01-01}, journal = {IEEE Transactions on Information Forensics and Security}, volume = {8}, number = {12}, pages = {2115--2126}, abstract = {This paper presents an objective evaluation of the effects of eye tracking specification and stimulus presentation on the biometric viability of complex eye movement patterns. Six spatial accuracy tiers (0.5°, 1.0°, 1.5°, 2.0°, 2.5°, 3.0°), six temporal resolution tiers (1000, 500, 250, 120, 75, 30 Hz), and five stimulus types (simple, complex, cognitive, textual, random) are evaluated to identify acceptable conditions under which to collect eye movement data. The results suggest the use of eye tracking equipment capable of at least 0.5° spatial accuracy and 250 Hz temporal resolution for biometric purposes, whereas stimulus had little effect on the biometric viability of eye movements.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This paper presents an objective evaluation of the effects of eye tracking specification and stimulus presentation on the biometric viability of complex eye movement patterns. Six spatial accuracy tiers (0.5°, 1.0°, 1.5°, 2.0°, 2.5°, 3.0°), six temporal resolution tiers (1000, 500, 250, 120, 75, 30 Hz), and five stimulus types (simple, complex, cognitive, textual, random) are evaluated to identify acceptable conditions under which to collect eye movement data. The results suggest the use of eye tracking equipment capable of at least 0.5° spatial accuracy and 250 Hz temporal resolution for biometric purposes, whereas stimulus had little effect on the biometric viability of eye movements. |
Seung Kweon Hong Comparison of vertical and horizontal eye movement times in the selection of visual targets by an eye input device Journal Article Journal of the Ergonomics Society of Korea, 34 (1), pp. 19–27, 2015. @article{Hong2015, title = {Comparison of vertical and horizontal eye movement times in the selection of visual targets by an eye input device}, author = {Seung Kweon Hong}, doi = {10.5143/JESK.2015.34.1.19}, year = {2015}, date = {2015-01-01}, journal = {Journal of the Ergonomics Society of Korea}, volume = {34}, number = {1}, pages = {19--27}, abstract = {Objective: The aim of this study is to investigate how well eye movement times in visual target selection tasks by an eye input device follows the typical Fitts' Law and to compare vertical and horizontal eye movement times. Background: Typically manual pointing provides excellent fit to the Fitts' Law model. However, when an eye input device is used for the visual target selection tasks, there were some debates on whether the eye movement times in can be described by the Fitts' Law. More empirical studies should be added to resolve these debates. This study is an empirical study for resolving this debate. On the other hand, many researchers reported the direction of movement in typical manual pointing has some effects on the movement times. The other question in this study is whether the direction of eye movement also affects the eye movement times. Method: A cursor movement times in visual target selection tasks by both input devices were collected. The layout of visual targets was set up by two types. Cursor starting position for vertical movement times were in the top of the monitor and visual targets were located in the bottom, while cursor starting positions for horizontal movement times were in the right of the monitor and visual targets were located in the left. Results: Although eye movement time was described by the Fitts' Law, the error rate was high and correlation was relatively low (R2 = 0.80 for horizontal movements and R2 = 0.66 for vertical movements), compared to those of manual movement. According to the movement direction, manual movement times were not significantly different, but eye movement times were significantly different. Conclusion: Eye movement times in the selection of visual targets by an eye-gaze input device could be described and predicted by the Fitts' Law. Eye movement times were significantly different according to the direction of eye movement. Application: The results of this study might help to understand eye movement times in visual target selection tasks by the eye input devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Objective: The aim of this study is to investigate how well eye movement times in visual target selection tasks by an eye input device follows the typical Fitts' Law and to compare vertical and horizontal eye movement times. Background: Typically manual pointing provides excellent fit to the Fitts' Law model. However, when an eye input device is used for the visual target selection tasks, there were some debates on whether the eye movement times in can be described by the Fitts' Law. More empirical studies should be added to resolve these debates. This study is an empirical study for resolving this debate. On the other hand, many researchers reported the direction of movement in typical manual pointing has some effects on the movement times. The other question in this study is whether the direction of eye movement also affects the eye movement times. Method: A cursor movement times in visual target selection tasks by both input devices were collected. The layout of visual targets was set up by two types. Cursor starting position for vertical movement times were in the top of the monitor and visual targets were located in the bottom, while cursor starting positions for horizontal movement times were in the right of the monitor and visual targets were located in the left. Results: Although eye movement time was described by the Fitts' Law, the error rate was high and correlation was relatively low (R2 = 0.80 for horizontal movements and R2 = 0.66 for vertical movements), compared to those of manual movement. According to the movement direction, manual movement times were not significantly different, but eye movement times were significantly different. Conclusion: Eye movement times in the selection of visual targets by an eye-gaze input device could be described and predicted by the Fitts' Law. Eye movement times were significantly different according to the direction of eye movement. Application: The results of this study might help to understand eye movement times in visual target selection tasks by the eye input devices. |
Yu feng Huang; Feng yang Kuo; Yu feng Huang; Feng yang Kuo An eye-tracking investigation of internet consumers' decision deliberateness Journal Article Internet Research, 21 (5), pp. 541–561, 2011. @article{Huang2011, title = {An eye-tracking investigation of internet consumers' decision deliberateness}, author = {Yu feng Huang and Feng yang Kuo and Yu feng Huang and Feng yang Kuo}, doi = {10.1108/10662241111176362}, year = {2011}, date = {2011-01-01}, journal = {Internet Research}, volume = {21}, number = {5}, pages = {541--561}, abstract = {Purpose – Because presentation formats, i.e. table v. graph, in shopping web sites may promote or inhibit deliberate consumer decision making, it is important to understand the effects of information presentation on deliberateness. This paper seeks to empirically test whether the table format enhances deliberate decision making, while the web map weakens the process. In addition, deliberateness can be influenced by the decision orientation, i.e. emotionally charged or accuracy oriented. Thus, the paper further examines the effect of presentations across these two decision orientations. Design/methodology/approach – Objective and detailed description of the decision process is used to examine the effects. A two (decision orientation: positive emotion v. accuracy) by two (presentation: map v. table) eye-tracking experiment is designed. Deliberateness is quantified with the information processing pattern summarized from eye movement data. Participants are required to make preferential choices from simple decision tasks. Findings – The results confirm that the table strengthens while the map weakens deliberateness. In addition, this effect is mostly evident across the two decision orientations. An explorative factor analysis further reveals that there are two major attention distribution functions (global v. local) underlying the decision process. Research limitations/implications – Only simple decision tasks are used in the present study and therefore complex tasks should be introduced to examine the effects in the future. Practical implications – For consumers, they should become aware that the table facilitates while the map diminishes deliberateness. For web businesses, they may try to strengthen the impulsivity in a web map filled with emotional stimuli. Originality/value – This research is one of the first attempts to investigate the joint effects of presentations and decision orientations on decision deliberateness in the internet domain. The eye movement data are also valuable because previous studies seldom provided such detailed description of the decision process.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Purpose – Because presentation formats, i.e. table v. graph, in shopping web sites may promote or inhibit deliberate consumer decision making, it is important to understand the effects of information presentation on deliberateness. This paper seeks to empirically test whether the table format enhances deliberate decision making, while the web map weakens the process. In addition, deliberateness can be influenced by the decision orientation, i.e. emotionally charged or accuracy oriented. Thus, the paper further examines the effect of presentations across these two decision orientations. Design/methodology/approach – Objective and detailed description of the decision process is used to examine the effects. A two (decision orientation: positive emotion v. accuracy) by two (presentation: map v. table) eye-tracking experiment is designed. Deliberateness is quantified with the information processing pattern summarized from eye movement data. Participants are required to make preferential choices from simple decision tasks. Findings – The results confirm that the table strengthens while the map weakens deliberateness. In addition, this effect is mostly evident across the two decision orientations. An explorative factor analysis further reveals that there are two major attention distribution functions (global v. local) underlying the decision process. Research limitations/implications – Only simple decision tasks are used in the present study and therefore complex tasks should be introduced to examine the effects in the future. Practical implications – For consumers, they should become aware that the table facilitates while the map diminishes deliberateness. For web businesses, they may try to strengthen the impulsivity in a web map filled with emotional stimuli. Originality/value – This research is one of the first attempts to investigate the joint effects of presentations and decision orientations on decision deliberateness in the internet domain. The eye movement data are also valuable because previous studies seldom provided such detailed description of the decision process. |