Frederik Platten; Maximilian Schwalm; Julia Hülsmann; Josef Krems
Analysis of compensative behavior in demanding driving situations Journal Article
In: Transportation Research Part F: Traffic Psychology and Behaviour, vol. 26, no. A, pp. 38–48, 2014.
Drivers usually perform a range of different activities while driving. Following a classical workload approach, additional activities are expected to increase the demand on the driver. Nevertheless, drivers can usually manage even demanding situations successfully. They seem to be able to compensate demands by behavior adaptations, mainly in the following factors: in the driving task itself, in an additional (secondary) task and in their mental workload. It is suggested that by analyzing these three factors in temporal coherence, compensative interactions between them become measurable. Additionally, a reduction of activity in the secondary task is expected to be influenced by the characteristics of this task. To analyze these effects, a driving simulator study with 33 participants was accomplished. It could be shown that if a secondary task can be interrupted without a perceived decline in performance, it is interrupted in demanding driving situations. If an interruption causes a perceived performance loss, efforts are increased, and so the workload is heightened (measured with a high resolution physiological measurement based on pupillometry). Thus, drivers compensate their current demands by behavior adaptations in different factors, depending on the characteristics of a secondary task.
Ioannis Rigas; Oleg V. Komogortsev
Biometric recognition via probabilistic spatial projection of eye movement trajectories in dynamic visual environments Journal Article
In: IEEE Transactions on Information Forensics and Security, vol. 9, no. 10, pp. 1743–1754, 2014.
This paper proposes a method for the extraction of biometric features from the spatial patterns formed by eye movements during an inspection of dynamic visual stimulus. In the suggested framework, each eye movement signal is transformed into a time-constrained decomposition by using a probabilistic representation of spatial and temporal features related to eye fixations and called fixation density map (FDM). The results for a large collection of eye movements recorded from 200 individuals indicate the best equal error rate of 10.8% and Rank-1 identification rate as high as 51%, which is a significant improvement over existing eye movement-driven biometric methods. In addition, our experiments reveal that a person recognition approach based on the FDM performs well even in cases when eye movement data are captured at lower than optimum sampling frequencies. This property is very important for the future ocular biometric systems where existing iris recognition devices could be employed to combine eye movement traits with iris information for increased security and accuracy. Considering that commercial iris recognition devices are able to implement eye image sampling usually at a relatively low rate, the ability to perform eye movement-driven biometrics at such rates is of great significance.
Germán Sanchis-Trilles; Vicent Alabau; Christian Buck; Michael Carl; Francisco Casacuberta; Mercedes García-Martínez; Ulrich Germann; Jesús González-Rubio; Robin L. Hill; Philipp Koehn; Luis A. Leiva; Bartolomé Mesa-Lao; Daniel Ortiz-Martínez; Herve Saint-Amand; Chara Tsoukala; Enrique Vidal
Interactive translation prediction versus conventional post-editing in practice: A study with the CasMaCat workbench Journal Article
In: Machine Translation, vol. 28, no. 3-4, pp. 217–235, 2014.
We conducted a field trial in computer-assisted professional translation to compare interactive translation prediction (ITP) against conventional post-editing (PE) of machine translation (MT) output. In contrast to the conventional PE set-up, where an MT system first produces a static translation hypothesis that is then edited by a professional (hence post-editing), ITP constantly updates the translation hypothesis in real time in response to user edits. Our study involved nine professional translators and four reviewers working with the web-based CasMaCat workbench. Various new interactive features aiming to assist the post-editor/translator were also tested in this trial. Our results show that even with little training, ITP can be as productive as conventional PE in terms of the total time required to produce the final translation. Moreover, translation editors working with ITP require fewer key strokes to arrive at the final version of their translation.
Lutz Schega; Daniel Hamacher; Sandra Erfuth; Wolfgang Behrens-Baumann; Juliane Reupsch; Michael B. Hoffmann
Differential effects of head-mounted displays on visual performance Journal Article
In: Ergonomics, vol. 57, no. 1, pp. 1–11, 2014.
Head-mounted displays (HMDs) virtually augment the visual world to aid visual task completion. Three types of HMDs were compared [look around (LA); optical see-through with organic light emitting diodes and virtual retinal display] to determine whether LA, leaving the observer functionally monocular, is inferior. Response times and error rates were determined for a combined visual search and Go-NoGo task. The costs of switching between displays were assessed separately. Finally, HMD effects on basic visual functions were quantified. Effects of HMDs on visual search and Go-NoGo task were small, but for LA display-switching costs for the Go-NoGo-task the effects were pronounced. Basic visual functions were most affected for LA (reduced visual acuity and visual field sensitivity, inaccurate vergence movements and absent stereo-vision). LA involved comparatively high switching costs for the Go-NoGo task, which might indicate reduced processing of external control cues. Reduced basic visual functions are a likely cause of this effect.
Jennifer G. Tichon; Timothy Mavin; Guy Wallis; Troy A. W. Visser; Stephan Riek
Using pupillometry and electromyography to track positive and negative affect during flight simulation Journal Article
In: Aviation Psychology and Applied Human Factors, vol. 4, no. 1, pp. 23–32, 2014.
Affect is a key determinant of performance, due to its influence on cognitive processing. Negative emotions such as anxiety are recognized cognitive stressors shown to degrade decision making and situation awareness. Conversely, positive affect can improve problem solving and facilitate recall. This exploratory pilot study used electromyography and pupillometry measures to track pilots' levels of negative and positive affect while training in a flight simulator. Fixation duration and saccade rate were found to correspond reliably to pilot self-reports of anxiety. Additionally, large increases in muscle activation were also recorded when higher anxiety was reported. Decreases in positive affect correlated significantly with saccade rate, fixation duration, and mean saccade velocity. Results are discussed in terms of using psychophysiological measures to provide a continuous, objective measure of pilot affective levels as an additional evaluation method to support assessment of pilot performance in simulation training environments.
Yusuke Uchida; Nobuaki Mizuguchi; Masaaki Honda; Kazuyuki Kanosue
Prediction of shot success for basketball free throws: Visual search strategy Journal Article
In: European Journal of Sport Science, vol. 14, no. 5, pp. 426–432, 2014.
Abstract In ball games, players have to pay close attention to visual information in order to predict the movements of both the opponents and the ball. Previous studies have indicated that players primarily utilise cues concerning the ball and opponents' body motion. The information acquired must be effective for observing players to select the subsequent action. The present study evaluated the effects of changes in the video replay speed on the spatial visual search strategy and ability to predict free throw success. We compared eye movements made while observing a basketball free throw by novices and experienced basketball players. Correct response rates were close to chance (50%) at all video speeds for the novices. The correct response rate of experienced players was significantly above chance (and significantly above that of the novices) at the normal speed, but was not different from chance at both slow and fast speeds. Experienced players gazed more on the lower part of the player's body when viewing a normal speed video than the novices. The players likely detected critical visual information to predict shot success by properly moving their gaze according to the shooter's movements. This pattern did not change when the video speed was decreased, but changed when it was increased. These findings suggest that temporal information is important for predicting action outcomes and that such outcomes are sensitive to video speed.
Boris M. Velichkovsky; Mikhail A. Rumyantsev; Mikhail A. Morozov
New solution to the Midas Touch Problem: Identification of visual commands via extraction of focal fixations Journal Article
In: Procedia Computer Science, vol. 39, pp. 75–82, 2014.
Reliable identification of intentional visual commands is a major problem in the development of eye-movements based user interfaces. This work suggests that the presence of focal visual fixations is indicative of visual commands. Two experiments are described which assessed the effectiveness of this approach in a simple gaze-control interface. Identification accuracy was shown to match that of the commonly used dwell time method. Using focal fixations led to less visual fatigue and higher speed of work. Perspectives of using focal fixations for identification of visual commands in various kinds of eye-movements based interfaces are discussed.
Jingwen Yang; Frederic Hamelin; Dominique Sauter
Fault detection observer design using time and frequency domain specifications Journal Article
In: IFAC Proceedings Volumes, vol. 19, no. 1, pp. 8564–8569, 2014.
Several scholars have proposed personalization models based on product variety breadth and the intensity of customer-firm interaction with a focus on marketing strategies ranging from basic product versioning to customerization and reverse marketing. However, some studies have shown that the explosion of product variety may generate information overload. Moreover, customers are highly heterogeneous in willingness and ability to interact with firms in personalization processes. This often results in consumer confusion and wasteful investments. To address this problem, we propose a conceptual framework of e-customer profiling for interactive personalization by distinguishing content (that is, expected customer benefits) and process (that is, expected degree of interaction) issues. The framework focuses on four general dimensions suggested by previous research as significant drivers of online customer heterogeneity: VALUE, KNOWLEDGE, ORIENTATION, and RELATIONSHIP QUALITY. We also present a preliminary test of the framework and derive directions for customer relationship management and future research.
Yasuhiro Seya; Hidetoshi Nakayasu; Tadasu Yagi
Useful field of view in simulated driving: Reaction times and eye movements of drivers Journal Article
In: i-Perception, vol. 4, no. 4, pp. 285–298, 2013.
To examine the spatial distribution of a useful field of view (UFOV) in driving, reaction times (RTs) and eye movements were measured in simulated driving. In the experiment, a normal or mirror-reversed letter "E" was presented on driving images with different eccentricities and directions from the current gaze position. The results showed significantly slower RTs in the upper and upper left directions than in the other directions. The RTs were significantly slower in the left directions than in the right directions. These results suggest that the UFOV in driving may be asymmetrical among the meridians in the visual field.
Heather Sheridan; Eyal M. Reingold
The mechanisms and boundary conditions of the Einstellung Effect in chess: Evidence from eye movements Journal Article
In: PLoS ONE, vol. 8, no. 10, pp. e75796, 2013.
In a wide range of problem-solving settings, the presence of a familiar solution can block the discovery of better solutions (i.e., the Einstellung effect). To investigate this effect, we monitored the eye movements of expert and novice chess players while they solved chess problems that contained a familiar move (i.e., the Einstellung move), as well as an optimal move that was located in a different region of the board. When the Einstellung move was an advantageous (but suboptimal) move, both the expert and novice chess players who chose the Einstellung move continued to look at this move throughout the trial, whereas the subset of expert players who chose the optimal move were able to gradually disengage their attention from the Einstellung move. However, when the Einstellung move was a blunder, all of the experts and the majority of the novices were able to avoid selecting the Einstellung move, and both the experts and novices gradually disengaged their attention from the Einstellung move. These findings shed light on the boundary conditions of the Einstellung effect, and provide convergent evidence for Bilalić, McLeod, & Gobet (2008)'s conclusion that the Einstellung effect operates by biasing attention towards problem features that are associated with the familiar solution rather than the optimal solution.
Michael Stengel; Martin Eisemann; Stephan Wenger; Benjamin Hell; Marcus Magnor
Optimizing apparent display resolution enhancement for arbitrary videos Journal Article
In: IEEE Transactions on Image Processing, vol. 22, no. 9, pp. 3604–3613, 2013.
Display resolution is frequently exceeded by available image resolution. Recently, apparent display resolution enhancement (ADRE) techniques show how characteristics of the human visual system can be exploited to provide super-resolution on high refresh rate displays. In this paper, we address the problem of generalizing the ADRE technique to conventional videos of arbitrary content. We propose an optimization-based approach to continuously translate the video frames in such a way that the added motion enables apparent resolution enhancement for the salient image region. The optimization considers the optimal velocity, smoothness, and similarity to compute an appropriate trajectory. In addition, we provide an intuitive user interface that allows to guide the algorithm interactively and preserves important compositions within the video. We present a user study evaluating apparent rendering quality and show versatility of our method on a variety of general test scenes.
Feng-Yi Tseng; Chin-Jung Chao; Wen-Yang Feng; Sheue-Ling Hwang
Effects of display modality on critical battlefield e-map search performance Journal Article
In: Behaviour and Information Technology, vol. 32, no. 9, pp. 888–901, 2013.
Visual search performance in visual display terminals can be affected by several changeable display parameters, such as the dimensions of screen, target size and background clutter. We found that when there was time pressure for operators to execute the critical battlefield map searching in a control room, efficient visual search became more important. We investigated the visual search performance in a simulated radar interface, which included the warrior symbology. Thirty-six participants were recruited and a three-factor mixed design was used in which the independent variables were three screen dimensions (7, 15 and 21 in.), five icon sizes (visual angle 40, 50, 60, 70 and 80 min of arc) and two map background clutter types (topography displayed [TD] and topography not displayed [TND]). The five dependent variables were completion time, accuracy, fixation duration, fixation count and saccade amplitude. The results showed that the best icon sizes were 80 and 70 min. The 21 in. screen dimension was chosen as the superior screen for search tasks. The TND map background with less clutters produced higher accuracy compared to that of TD background with clutter. The results of this research can be used in control room design to promote operators' visual search performance.
Lisa Stockhausen; Sara Koeser; Sabine Sczesny
The gender typicality of faces and its impact on visual processing and on hiring decisions Journal Article
In: Experimental Psychology, vol. 60, no. 6, pp. 444–452, 2013.
Past research has shown that the gender typicality of applicants' faces affects leadership selection irrespective of a candidate's gender: A masculine facial appearance is congruent with masculine-typed leadership roles, thus masculine-looking applicants are hired more certainly than feminine-looking ones. In the present study, we extended this line of research by investigating hiring decisions for both masculine- and feminine-typed professional roles. Furthermore, we used eye tracking to examine the visual exploration of applicants' portraits. Our results indicate that masculine-looking applicants were favored for the masculine-typed role (leader) and feminine-looking applicants for the feminine-typed role (team member). Eye movement patterns showed that information about gender category and facial appearance was integrated during first fixations of the portraits. Hiring decisions, however, were not based on this initial analysis, but occurred at a second stage, when the portrait was viewed in the context of considering the applicant for a specific job.
An iPad app as a low-vision aid for people with macular disease Journal Article
In: British Journal of Ophthalmology, vol. 97, no. 1, pp. 110–112, 2013.
Age-related macular degeneration (AMD) is the single most common cause of vision loss in people over the age of 50. Individuals with low vision caused by macular disease, experience severe difficulty with everyday tasks such as reading, which has profound detrimental consequences for their quality of life. We have developed an app for the iPad (the MD evReader) that aims to improve reading (of electronic books) by enhancing the effectiveness of the eccentric viewing technique (EV) using dynamic text presentation. Eccentric viewing is a simple strategy adopted by individuals with AMD that involves using the relatively preserved peripheral region of their retina in order to see. A limiting factor of the EV technique is that it relies on the individual holding their gaze away from the focus of interest and suppressing the natural and strong, tendency to make eye-movements (saccades). During normal reading, for example, a stereotypical pattern of horizontal saccades are made, from left-to-right, enabling fixations to be made on each word4 – Figure 1a). The natural inclination to make saccades is, however, difficult to suppress and limits the effectiveness of eccentric viewing in people with macular disease.
Chenjiang Xie; Tong Zhu; Chunlin Guo; Yimin Zhang
Measuring IVIS impact to driver by on-road test and simulator experiment Journal Article
In: Procedia Social and Behavioral Sciences, vol. 96, pp. 1566–1577, 2013.
This work examined the effects of using in-vehicle information systems (IVIS) on drivers by on-road test and simulator experiment. Twelve participants participated in the test. In on-road test, drivers performed driving task with voice prompt and non-voice prompt navigation device mounted on different position. In simulator experiment, secondary tasks, including cognitive, visual and manual tasks, were performed in a driving simulator. Subjective rating was used to test mental workload of drivers in on-road test and simulator experiment. The impact of task complexity and reaction mode was investigated in this paper. The results of the test and the simulation showed that position 1 was more comfortable than other two positions for drivers and it would cause less mental load. Drivers tend to support this result in subjective rating. IVIS with voice prompt causes less visual demand to drivers. The mental load will grow as the difficulty of the task increasing. The cognitive task on manual reaction causes higher mental load than cognitive task which doesn't require manual reaction. These results may have practical implications for in-vehicle information system design.
Li Zhang; Jie Ren; Liang Xu; Xue Jun Qiu; Jost B. Jonas
Visual comfort and fatigue when watching three-dimensional displays as measured by eye movement analysis Journal Article
In: British Journal of Ophthalmology, vol. 97, no. 7, pp. 941–942, 2013.
With the growth in three-dimensional viewing of movies, we assessed whether visual fatigue or alertness differed between three-dimensional (3D) viewing versus two- dimensional (2D) viewing of movies. We used a camera-based analysis of eye move- ments to measure blinking, fixation and sac- cades as surrogates of visual fatigue.
Li Zhang; Ya-Qin Zhang; Jing-Shang Zhang; Liang Xu; Jost B. Jonas
Visual fatigue and discomfort after stereoscopic display viewing Journal Article
In: Acta Ophthalmologica, vol. 91, no. 2, pp. 149–153, 2013.
Purpose: Different types of stereoscopic video displays have recently been introduced. We measured and compared visual fatigue and visual discomfort induced by viewing two different stereoscopic displays that either used the pattern retarder-spatial domain technology with linearly polarized three-dimensional technology or the circularly polarized three-dimensional technology using shutter glasses.; Methods: During this observational cross-over study performed at two subsequent days, a video was watched by 30 subjects (age: 20-30 years). Half of the participants watched the screen with a pattern retard three-dimensional display at the first day and a shutter glasses three-dimensional display at the second day, and reverse. The study participants underwent a standardized interview on visual discomfort and fatigue, and a series of functional examinations prior to, and shortly after viewing the movie. Additionally, a subjective score for visual fatigue was given.; Results: Accommodative magnitude (right eye: p < 0.001; left eye: p = 0.01), accommodative facility (p = 0.008), near-point convergence break-up point (p = 0.007), near-point convergence recover point (p = 0.001), negative (p = 0.03) and positive (p = 0.001) relative accommodation were significantly smaller, and the visual fatigue score was significantly higher (1.65 ± 1.18 versus 1.20 ± 1.03; p = 0.02) after viewing the shutter glasses three-dimensional display than after viewing the pattern retard three-dimensional display.; Conclusions: Stereoscopic viewing using pattern retard (polarized) three-dimensional displays as compared with stereoscopic viewing using shutter glasses three-dimensional displays resulted in significantly less visual fatigue as assessed subjectively, parallel to significantly better values of accommodation and convergence as measured objectively.
D. A. Baker; N. J. Schweitzer; Evan F. Risko; Jillian M. Ware
Visual attention and the neuroimage bias Journal Article
In: PLoS ONE, vol. 8, no. 9, pp. e74449, 2013.
Several highly-cited experiments have presented evidence suggesting that neuroimages may unduly bias laypeople's judgments of scientific research. This finding has been especially worrisome to the legal community in which neuroimage techniques may be used to produce evidence of a person's mental state. However, a more recent body of work that has looked directly at the independent impact of neuroimages on layperson decision-making (both in legal and more general arenas), and has failed to find evidence of bias. To help resolve these conflicting findings, this research uses eye tracking technology to provide a measure of attention to different visual representations of neuroscientific data. Finding an effect of neuroimages on the distribution of attention would provide a potential mechanism for the influence of neuroimages on higher-level decisions. In the present experiment, a sample of laypeople viewed a vignette that briefly described a court case in which the defendant's actions might have been explained by a neurological defect. Accompanying these vignettes was either an MRI image of the defendant's brain, or a bar graph depicting levels of brain activity-two competing visualizations that have been the focus of much of the previous research on the neuroimage bias. We found that, while laypeople differentially attended to neuroimagery relative to the bar graph, this did not translate into differential judgments in a way that would support the idea of a neuroimage bias.
Ana Margarida Barreto
Do users look at banner ads on Facebook? Journal Article
In: Journal of Research in Interactive Marketing, vol. 7, no. 2, pp. 119–139, 2013.
Purpose – The main purpose of this study was to determine whether users of the online social network site, Facebook, actually look at the ads displayed (briefly, to test the existence of the phenomenon known as “banner blindness” in this website), thus ascertaining the effectiveness of paid advertising, and comparing it with the number of friends' recommendations seen. Design/methodology/approach – In order to achieve this goal, an experiment using eye-tracking technology was administered to a total of 20 participants from a major university in the USA, followed by a questionnaire. Findings – Findings show that online ads attract less attention levels than friends' recommendations. A possible explanation for this phenomenon may be related to the fact that ads on Facebook are outside of the F-shaped visual pattern range, causing a state of “banner blindness”. Results also show that statistically there is no difference in ads seen and clicked between women and men. Research limitations/implications – The sample type (undergraduate and graduate students) and the sample size (20 participants) inhibit the generalization of the findings to other populations. Practical implications – The paper includes implications for the development of an effective online advertising campaign, as well as some proposed conceptualizations of the terms social network site and advertising, which can be used as platforms for discussion or as standards for future definitions. Originality/value – This study fulfils some identified needs to study advertising effectiveness based on empirical data and to assess banner blindness in other contexts, representative of current internet users' habits.
Raymond Bertram; Laura Helle; Johanna K. Kaakinen; Erkki Svedström
The effect of expertise on eye movement behaviour in medical image perception Journal Article
In: PLoS ONE, vol. 8, no. 6, pp. e66169, 2013.
The present eye-movement study assessed the effect of expertise on eye-movement behaviour during image perception in the medical domain. To this end, radiologists, computed-tomography radiographers and psychology students were exposed to nine volumes of multi-slice, stack-view, axial computed-tomography images from the upper to the lower part of the abdomen with or without abnormality. The images were presented in succession at low, medium or high speed, while the participants had to detect enlarged lymph nodes or other visually more salient abnormalities. The radiologists outperformed both other groups in the detection of enlarged lymph nodes and their eye-movement behaviour also differed from the other groups. Their general strategy was to use saccades of shorter amplitude than the two other participant groups. In the presence of enlarged lymph nodes, they increased the number of fixations on the relevant areas and reverted to even shorter saccades. In volumes containing enlarged lymph nodes, radiologists' fixation durations were longer in comparison to their fixation durations in volumes without enlarged lymph nodes. More salient abnormalities were detected equally well by radiologists and radiographers, with both groups outperforming psychology students. However, to accomplish this, radiologists actually needed fewer fixations on the relevant areas than the radiographers. On the basis of these results, we argue that expert behaviour is manifested in distinct eye-movement patterns of proactivity, reactivity and suppression, depending on the nature of the task and the presence of abnormalities at any given moment.
Leandro Luigi Di Stasi; Adoración Antolí; José J. Cañas
Evaluating mental workload while interacting with computer-generated artificial environments Journal Article
In: Entertainment Computing, vol. 4, no. 1, pp. 63–69, 2013.
The need to evaluate user behaviour and cognitive efforts when interacting with complex simulations plays a crucial role in many information and communications technologies. The aim of this paper is to propose the use of eye-related measures as indices of mental workload in complex tasks. An experiment was conducted using the FireChieftextregistered microworld in which user mental workload was manipulated by changing the interaction strategy required to perform a common task. There were significant effects of the attentional state of users on visual scanning behavior. Longer fixations were found for the more demanding strategy, slower saccades were found as the time-on-task increased, and pupil diameter decreased when an environmental change was introduced. Questionnaire and performance data converged with the psychophysiological ones. These results provide additional empirical support for the ability of some eye-related indices to discriminate variations in the attentional state of the user in visual-dynamic complex tasks and show their potential diagnostic capacity in the field of applied ergonomics.
Leandro Luigi Di Stasi; Andrés Catena; José J. Cañas; Stephen L. Macknik; Susana Martinez-Conde
Saccadic velocity as an arousal index in naturalistic tasks Journal Article
In: Neuroscience and Biobehavioral Reviews, vol. 37, no. 5, pp. 968–975, 2013.
Experimental evidence indicates that saccadic metrics vary with task difficulty and time-on-task in naturalistic scenarios. We explore historical and recent findings on the correlation of saccadic velocity with task parameters in clinical, military, and everyday situations, and its potential role in ergonomics. We moreover discuss the hypothesis that changes in saccadic velocity indicate variations in sympathetic nervous system activation; that is, variations in arousal.
Trafton Drew; Melissa L. -H. Võ; Alex Olwal; Francine Jacobson; Steven E. Seltzer; Jeremy M. Wolfe
Scanners and drillers: Characterizing expert visual search through volumetric images Journal Article
In: Journal of Vision, vol. 13, no. 10, pp. 1–13, 2013.
Modern imaging methods like computed tomography (CT) generate 3-D volumes of image data. How do radiologists search through such images? Are certain strategies more efficient? Although there is a large literature devoted to understanding search in 2-D, relatively little is known about search in volumetric space. In recent years, with the ever-increasing popularity of volumetric medical imaging, this question has taken on increased importance as we try to understand, and ultimately reduce, errors in diagnostic radiology. In the current study, we asked 24 radiologists to search chest CTs for lung nodules that could indicate lung cancer. To search, radiologists scrolled up and down through a "stack" of 2-D chest CT "slices." At each moment, we tracked eye movements in the 2-D image plane and coregistered eye position with the current slice. We used these data to create a 3-D representation of the eye movements through the image volume. Radiologists tended to follow one of two dominant search strategies: "drilling" and "scanning." Drillers restrict eye movements to a small region of the lung while quickly scrolling through depth. Scanners move more slowly through depth and search an entire level of the lung before moving on to the next level in depth. Driller performance was superior to the scanners on a variety of metrics, including lung nodule detection rate, percentage of the lung covered, and the percentage of search errors where a nodule was never fixated.
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
In: Applied Cognitive Psychology, vol. 27, no. 4, pp. 483–492, 2013.
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.
David J. Hancock; Diane M. Ste-Marie
Gaze behaviors and decision making accuracy of higher- and lower-level ice hockey referees Journal Article
In: Psychology of Sport & Exercise, vol. 14, no. 1, pp. 66–71, 2013.
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.
Alistair J. Harvey; Wendy Kneller; Alison C. Campbell
The effects of alcohol intoxication on attention and memory for visual scenes. Journal Article
In: Memory, vol. 21, no. 8, pp. 969–980, 2013.
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.
Corey D. Holland; Oleg V. Komogortsev
Complex eye movement pattern biometrics: The effects of environment and stimulus Journal Article
In: IEEE Transactions on Information Forensics and Security, vol. 8, no. 12, pp. 2115–2126, 2013.
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.
Olivia M. Maynard; Marcus R. Munafò; Ute Leonards
Visual attention to health warnings on plain tobacco packaging in adolescent smokers and non-smokers Journal Article
In: Addiction, vol. 108, no. 2, pp. 413–419, 2013.
AIMS: Previous research with adults indicates that plain packaging increases visual attention to health warnings in adult non-smokers and weekly smokers, but not daily smokers. The present research extends this study to adolescents aged 14-19 years. DESIGN: Mixed-model experimental design, with smoking status as a between-subjects factor and pack type (branded or plain pack) and eye gaze location (health warning or branding) as within-subjects factors. SETTING: Three secondary schools in Bristol, UK. PARTICIPANTS: A convenience sample of adolescents comprising never-smokers (n = 26), experimenters (n = 34), weekly smokers (n = 13) and daily smokers (n = 14). MEASUREMENTS: Number of eye movements to health warnings and branding on plain and branded packs. FINDINGS: Analysis of variance, irrespective of smoking status revealed more eye movements to health warnings than branding on plain packs, but an equal number of eye movements to both regions on branded packs (P = 0.033). This was observed among experimenters (P < 0.001) and weekly smokers (P = 0.047), but not among never-smokers or daily smokers. CONCLUSION: Among experimenters and weekly smokers, plain packaging increases visual attention to health warnings and away from branding. Daily smokers, even relatively early in their smoking careers, seem to avoid the health warnings on cigarette packs. Adolescent never-smokers attend the health warnings preferentially on both types of packs, a finding which may reflect their decision not to smoke.
Pierre-Vincent Paubel; Philippe Averty; Éric Raufaste
Effects of an automated conflict solver on the visual activity of air traffic controllers Journal Article
In: International Journal of Aviation Psychology, vol. 23, no. 2, pp. 181–196, 2013.
ERASMUS is a "subliminal" automated aid system designed to reduce air traffic controllers' workload. Prior experiments showed that ERASMUS reduced subjective ratings of mental workload. In this article, the effect of ERASMUS on objective measures of controllers' visual activity was tested in a fully realistic simulation environment. The eye movements of 7 controllers were recorded during experimental traffic sequences, with and without ERASMUS. Consistent with a reduced workload hypothesis, results showed medium to large effects of ERASMUS on the amplitude of saccades, on the time spent gazing at aircraft, and on the distribution of attention over the visual scene.
Adam M. Perkins; Ulrich Ettinger; K. Weaver; Anne Schmechtig; A. Schrantee; P. D. Morrison; A. Sapara; V. Kumari; Steve C. R. Williams; P. J. Corr
Advancing the defensive explanation for anxiety disorders: Lorazepam effects on human defense are systematically modulated by personality and threat-type Journal Article
In: Translational Psychiatry, vol. 3, pp. e246, 2013.
Clinically effective drugs against human anxiety and fear systematically alter the innate defensive behavior of rodents, suggesting that in humans these emotions reflect defensive adaptations. Compelling experimental human evidence for this theory is yet to be obtained. We report the clearest test to date by investigating the effects of 1 and 2 mg of the anti-anxiety drug lorazepam on the intensity of threat-avoidance behavior in 40 healthy adult volunteers (20 females). We found lorazepam modulated the intensity of participants' threat-avoidance behavior in a dose-dependent manner. However, the pattern of effects depended upon two factors: type of threat-avoidance behavior and theoretically relevant measures of personality. In the case of flight behavior (one-way active avoidance), lorazepam increased intensity in low scorers on the Fear Survey Schedule tissue-damage fear but reduced it in high scorers. Conversely, in the case of risk-assessment behavior (two-way active avoidance), lorazepam reduced intensity in low scorers on the Spielberger trait anxiety but increased it in high scorers. Anti-anxiety drugs do not systematically affect rodent flight behavior; therefore, we interpret this new finding as suggesting that lorazepam has a broader effect on defense in humans than in rodents, perhaps by modulating general perceptions of threat intensity. The different patterning of lorazepam effects on the two behaviors implies that human perceptions of threat intensity are nevertheless distributed across two different neural streams, which influence effects observed on one-way or two-way active avoidance demanded by the situation.
Judith Peth; Johann S. C. Kim; Matthias Gamer
Fixations and eye-blinks allow for detecting concealed crime related memories Journal Article
In: International Journal of Psychophysiology, vol. 88, no. 1, pp. 96–103, 2013.
The Concealed Information Test (CIT) is a method of forensic psychophysiology that allows for revealing concealed crime related knowledge. Such detection is usually based on autonomic responses but there is a huge interest in other measures that can be acquired unobtrusively. Eye movements and blinks might be such measures but their validity is unclear. Using a mock crime procedure with a manipulation of the arousal during the crime as well as the delay between crime and CIT, we tested whether eye tracking measures allow for detecting concealed knowledge. Guilty participants showed fewer but longer fixations on central crime details and this effect was even present after stimulus offset and accompanied by a reduced blink rate. These ocular measures were partly sensitive for induction of emotional arousal and time of testing. Validity estimates were moderate but indicate that a significant differentiation between guilty and innocent subjects is possible. Future research should further investigate validity differences between gaze measures during a CIT and explore the underlying mechanisms.
Hector Rieiro; Susana Martinez-Conde; Stephen L. Macknik
Perceptual elements in Penn & Teller's “Cups and Balls” magic trick Journal Article
In: PeerJ, vol. 1, pp. 1–12, 2013.
Magic illusions provide the perceptual and cognitive scientist with a toolbox of experimental manipulations and testable hypotheses about the building blocks of conscious experience. Here we studied several sleight-of-hand manipulations in the performance of the classic "Cups and Balls" magic trick (where balls appear and disappear inside upside-down opaque cups). We examined a version inspired by the entertainment duo Penn & Teller, conducted with three opaque and subsequently with three transparent cups. Magician Teller used his right hand to load (i.e. introduce surreptitiously) a small ball inside each of two upside-down cups, one at a time, while using his left hand to remove a different ball from the upside-down bottom of the cup. The sleight at the third cup involved one of six manipulations: (a) standard maneuver, (b) standard maneuver without a third ball, (c) ball placed on the table, (d) ball lifted, (e) ball dropped to the floor, and (f) ball stuck to the cup. Seven subjects watched the videos of the performances while reporting, via button press, whenever balls were removed from the cups/table (button "1") or placed inside the cups/on the table (button "2"). Subjects' perception was more accurate with transparent than with opaque cups. Perceptual performance was worse for the conditions where the ball was placed on the table, or stuck to the cup, than for the standard maneuver. The condition in which the ball was lifted displaced the subjects' gaze position the most, whereas the condition in which there was no ball caused the smallest gaze displacement. Training improved the subjects' perceptual performance. Occlusion of the magician's face did not affect the subjects' perception, suggesting that gaze misdirection does not play a strong role in the Cups and Balls illusion. Our results have implications for how to optimize the performance of this classic magic trick, and for the types of hand and object motion that maximize magic misdirection.
Loes T. E. Kessels; Robert A. C. Ruiter
Eye movement responses to health messages on cigarette packages Journal Article
In: BMC Public Health, vol. 12, no. 1, pp. 1–9, 2012.
BACKGROUND: While the majority of the health messages on cigarette packages contain threatening health information, previous studies indicate that risk information can trigger defensive reactions, especially when the information is self-relevant (i.e., smokers). Providing coping information, information that provides help for quitting smoking, might increase attention to health messages instead of triggering defensive reactions.nnMETHODS: Eye-movement registration can detect attention preferences for different health education messages over a longer period of time during message exposure. In a randomized, experimental study with 23 smoking and 41 non-smoking student volunteers, eye-movements were recorded for sixteen self-created cigarette packages containing health texts that presented either high risk or coping information combined with a high threat or a low threat smoking-related photo.nnRESULTS: Results of the eye movement data showed that smokers tend to spend more time looking (i.e., more unique fixations and longer dwell time) at the coping information than at the high risk information irrespective of the content of the smoking-related photo. Non-smokers tend to spend more time looking at the high risk information than at the coping information when the information was presented in combination with a high threat smoking photo. When a low threat photo was presented, non-smokers paid more attention to the coping information than to the high risk information. Results for the smoking photos showed more attention allocation for low threat photos that were presented in combination with high risk information than for low threat photos in combination with coping information. No attention differences were found for the high threat photos.nnCONCLUSIONS: Non-smokers demonstrated an attention preference for high risk information as opposed to coping information, but only when text information was presented in combination with a high threat photo. For smokers, however, our findings suggest more attention allocation for coping information than for health risk information. This preference for coping information is not reflected in current health messages to motivate smokers to quit smoking. Coping information should be more frequently implemented in health message design to increase attention for these messages and thus contribute to effective persuasion.
Rachel McDonnell; Martin Breidty; Heinrich H. Bülthoff
Render me real? Investigating the effect of render style on the perception of animated virtual humans Journal Article
In: ACM Transactions on Graphics, vol. 31, no. 4, pp. 1–11, 2012.
The realistic depiction of lifelike virtual humans has been the goal of many movie makers in the last decade. Recently, films such as Tron: Legacy and The Curious Case of Benjamin Button have produced highly realistic characters. In the real-time domain, there is also a need to deliver realistic virtual characters, with the increase in popularity of interactive drama video games (such as L.A. NoireTM or Heavy RainTM). There have been mixed reactions from audiences to lifelike characters used in movies and games, with some saying that the increased realism highlights subtle imperfections, which can be disturbing. Some developers opt for a stylized rendering (such as cartoon-shading) to avoid a negative reaction [Thompson 2004]. In this paper, we investigate some of the consequences of choosing realistic or stylized rendering in order to provide guidelines for developers for creating appealing virtual characters. We conducted a series of psychophysical experiments to determine whether render style affects how virtual humans are perceived. Motion capture with synchronized eye-tracked data was used throughout to animate custom-made virtual model replicas of the captured actors.
Marion G. Müller; Arvid Kappas; Bettina Olk
Perceiving press photography: A new integrative model, combining iconology with psychophysiological and eye-tracking methods Journal Article
In: Visual Communication, vol. 11, no. 3, pp. 307–328, 2012.
Any analysis of how mass-mediated visuals are perceived and interpreted in multimodal contexts should be informed by a scientific understanding of the biological constraints on visual processing, as well as a solid culturally aware visual communication approach. This article focuses on the interdis- ciplinary combination of three methods – iconology, a qualitative method of visual analysis targeted at the meanings of visuals and based in the humanities, and eye-tracking and psychophysiological reaction measure- ment, both based in experimental psychology. The authors propose a Visual Communication Process Model as an integrative means for connecting dif- ferent facets of the communication processes involved in visual mass com- munication. The goal of this new model is to widen and sharpen the focus on explaining (a) meaning-attribution processes, (b) visual perception and attention processes, and (c) psychophysiological reactions to mass-medi- ated visuals, illustrated in this article with examples of press photography.
Kristien Ooms; Philippe De Maeyer; Veerle Fack; Eva Van Assche; Frank Witlox
Investigating the effectiveness of an efficient label placement method using eye movement data Journal Article
In: The Cartographic Journal, vol. 49, no. 3, pp. 234–246, 2012.
This paper focuses on improving the efficiency and effectiveness of dynamic and interactive maps in relation to the user. A label placement method with an improved algorithmic efficiency is presented. Since this algorithm has an influence on the actual placement of the name labels on the map, it is tested if this efficient algorithms also creates more effective maps: how well is the information processed by the user. We tested 30 participants while they were working on a dynamic and interactive map display. Their task was to locate geographical names on each of the presented maps. Their eye movements were registered together with the time at which a given label was found. The gathered data reveals no difference in the user's response times, neither in the number and the duration of the fixations between both map designs. The results of this study show that the efficiency of label placement algorithms can be improved without disturbing the user's cognitive map. Consequently, we created a more efficient map without affecting it's effectiveness towards the user.
Kristien Ooms; Philippe De Maeyer; Veerle Fack; Eva Van; Frank Witlox
Interpreting maps through the eyes of expert and novice users Journal Article
In: International Journal of Geographical Information Science, vol. 26, no. 10, pp. 1773–1788, 2012.
The experiments described in this article combine response time measurements and eye movement data to gain insight into the users' cognitive processes while working with dynamic and interactive maps. Experts and novices participated in a user study with a ‘between user' design. Twenty screen maps were presented in a random order to each participant, on which he had to execute a visual search. The combined information of the button actions and eye tracker reveals that both user groups showed a similar pattern in the time intervals needed to locate the subsequent names. From this pattern, information about the users' cognitive load could be derived: use of working memory, learning effect and so on. Moreover, the response times also showed that experts were significantly faster in finding the names in the map image. This is further explained by the eye movement metrics: experts had significantly shorter fixations and more fixations per second meaning that they could interpret a larger part of the map in the same amount of time. As a consequence, they could locate objects in the map image more efficiently and thus faster.
Michael J. Seiler; Poornima Madhavan; Molly Liechty
Ocular tracking and the behavioral effects of negative externalities on perceived property values Journal Article
In: Journal of Housing Research, vol. 21, no. 2, pp. 123–137, 2012.
This study proposes an alternative valuation technique to the standard hedonic model. Specifically, in the context of an experimental design, we use ocular tracking technology (dwell time, fixation duration, and saccade amplitude) to follow the eye movements of perspective homebuyers and a sample of student participants while searching for homes on the Internet. We superimpose ominous power lines in matched samples to just one home of the 10 homes that participants toured. Walls of another home within the tour package are artificially painted pink. Again using matched samples to compare results, we find that people rationally differentiate between negative externalities that can easily be changed (pink walls) versus those that cannot (power lines).
Yusuke Uchida; Daisuke Kudoh; Akira Murakami; Masaaki Honda; Shigeru Kitazawa
Origins of superior dynamic visual acuity in baseball players: Superior eye movements or superior image processing Journal Article
In: PLoS ONE, vol. 7, no. 2, pp. e31530, 2012.
Dynamic visual acuity (DVA) is defined as the ability to discriminate the fine parts of a moving object. DVA is generally better in athletes than in non-athletes, and the better DVA of athletes has been attributed to a better ability to track moving objects. In the present study, we hypothesized that the better DVA of athletes is partly derived from better perception of moving images on the retina through some kind of perceptual learning. To test this hypothesis, we quantitatively measured DVA in baseball players and non-athletes using moving Landolt rings in two conditions. In the first experiment, the participants were allowed to move their eyes (free-eye-movement conditions), whereas in the second they were required to fixate on a fixation target (fixation conditions). The athletes displayed significantly better DVA than the non-athletes in the free-eye-movement conditions. However, there was no significant difference between the groups in the fixation conditions. These results suggest that the better DVA of athletes is primarily due to an improved ability to track moving targets with their eyes, rather than to improved perception of moving images on the retina.
Shun-nan Yang; Yu-chi Tai; James E. Sheedy; Beth Kinoshita; Matthew Lampa; Jami R. Kern
Comparative effect of lens care solutions on blink rate, ocular discomfort and visual performance Journal Article
In: Ophthalmic and Physiological Optics, vol. 32, no. 5, pp. 412–420, 2012.
PURPOSE: To help maintain clear vision and ocular surface health, eye blinks occur to distribute natural tears over the ocular surface, especially the corneal surface. Contact lens wearers may suffer from poor vision and dry eye symptoms due to difficulty in lens surface wetting and reduced tear production. Sustained viewing of a computer screen reduces eye blinks and exacerbates such difficulties. The present study evaluated the wetting effect of lens care solutions (LCSs) on blink rate, dry eye symptoms, and vision performance. METHODS: Sixty-five adult habitual soft contact lens wearers were recruited to adapt to different LCSs (Opti-free, ReNu, and ClearCare) in a cross-over design. Blink rate in pictorial viewing and reading (measured with an eyetracker), dry eye symptoms (measured with the Ocular Surface Disease Index questionnaire), and visual discrimination (identifying tumbling E) immediately before and after eye blinks were measured after 2 weeks of adaption to LCS. Repeated measures anova and mixed model ancova were conducted to evaluate effects of LCS on blink rate, symptom score, and discrimination accuracy.nnRESULTS: Opti-Free resulted in lower dry eye symptoms (p = 0.018) than ClearCare, and lower spontaneous blink rate (measured in picture viewing) than ClearCare (p = 0.014) and ReNu (p = 0.041). In reading, blink rate was higher for ClearCare compared to ReNu (p = 0.026) and control (p = 0.024). Visual discrimination time was longer for the control (daily disposable lens) than for Opti-Free (p = 0.007), ReNu (p = 0.009), and ClearCare (0.013) immediately before the blink.nnCONCLUSIONS: LCSs differently affected blink rate, subjective dry eye symptoms, and visual discrimination speed. Those with wetting agents led to significantly fewer eye blinks while affording better ocular comfort for contact lens wearers, compared to that without. LCSs with wetting agents also resulted in better visual performance compared to wearing daily disposable contact lenses. These presumably are because of improved tear film quality.
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
In: Applied Ergonomics, vol. 43, no. 1, pp. 48–56, 2012.
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
In: Transportation Research Part C: Emerging Technologies, vol. 21, no. 1, pp. 122–133, 2012.
Developing a valid measurement of mental fatigue remains a big challenge and would be beneficial for various application areas, such as the improvement of road traffic safety. In the present study we examined influences of mental fatigue on the dynamics of saccadic eye movements. Based on previous findings, we propose that among amplitude and duration of saccades, the peak velocity of saccadic eye movements is particularly sensitive to changes in mental fatigue. Ten participants completed a fixation task before and after 2. h of driving in a virtual simulation environment as well as after a rest break of fifteen minutes. Driving and rest break were assumed to directly influence the level of mental fatigue and were evaluated using subjective ratings and eye movement indices. According to the subjective ratings, mental fatigue was highest after driving but decreased after the rest break. The peak velocity of saccadic eye movements decreased after driving while the duration of saccades increased, but no effects of the rest break were observed in the saccade parameters. We conclude that saccadic eye movement parameters-particularly the peak velocity-are sensitive indicators for mental fatigue. According to these findings, the peak velocity analysis represents a valid on-line measure for the detection of mental fatigue, providing the basis for the development of new vigilance screening tools to prevent accidents in several application domains.
Kai Christoph Hamborg; M. Bruns; F. Ollermann; Kai Kaspar
The effect of banner animation on fixation behavior and recall performance in search tasks Journal Article
In: Computers in Human Behavior, vol. 28, no. 2, pp. 576–582, 2012.
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.
Mary Hegarty; Harvey S. Smallman; Andrew T. Stull
Choosing and using geospatial displays: Effects of design on performance and metacognition Journal Article
In: Journal of Experimental Psychology: Applied, vol. 18, no. 1, pp. 1–17, 2012.
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.
George J. Andersen; Rui Ni; Zheng Bian; Julie Kang
Limits of spatial attention in three-dimensional space and dual-task driving performance Journal Article
In: Accident Analysis and Prevention, vol. 43, no. 1, pp. 381–390, 2011.
The present study examined the limits of spatial attention while performing two driving relevant tasks that varied in depth. The first task was to maintain a fixed headway distance behind a lead vehicle that varied speed. The second task was to detect a light-change target in an array of lights located above the roadway. In Experiment 1 the light detection task required drivers to encode color and location. The results indicated that reaction time to detect a light-change target increased and accuracy decreased as a function of the horizontal location of the light-change target and as a function of the distance from the driver. In a second experiment the light change task was changed to a singleton search (detect the onset of a yellow light) and the workload of the car following task was systematically varied. The results of Experiment 2 indicated that RT increased as a function of task workload, the 2D position of the light-change target and the distance of the light-change target. A multiple regression analysis indicated that the effect of distance on light detection performance was not due to changes in the projected size of the light target. In Experiment 3 we found that the distance effect in detecting a light change could not be explained by the location of eye fixations. The results demonstrate that when drivers attend to a roadway scene attention is limited in three-dimensional space. These results have important implications for developing tests for assessing crash risk among drivers as well as the design of in vehicle technologies such as head-up displays.
Nicola C. Anderson; Evan F. Risko; Alan Kingstone
Exploiting human sensitivity to gaze for tracking the eyes Journal Article
In: Behavior Research Methods, vol. 43, pp. 843–852, 2011.
Given the prevalence, quality, and low cost of web cameras, along with the remarkable human sensitivity to gaze, we examined the accuracy of eye tracking using only a web camera. Participants were shown webcamera recordings of a person's eyes moving 1°, 2°, or 3° of visual angle in one of eight radial directions (north, northeast, east, southeast, etc.), or no eye movement occurred at all. Observers judged whether an eye movement was made and, if so, its direction. Our findings demonstrate that for all saccades of any size or direction, observers can detect and discriminate eye movements significantly better than chance. Critically, the larger the saccade, the better the judgments, so that for eye movements of 3°, people can tell whether an eye movement occurred, and where it was going, at about 90% or better. This simple methodology of using a web camera and looking for eye movements offers researchers a simple, reliable, and cost-effective research tool that can be applied effectively both in studies where it is important that participants maintain central fixation (e.g., covert attention investigations) and in those where they are free or required to move their eyes (e.g., visual search).
Rouwen Cañal-Bruland; Simone Lotz; Norbert Hagemann; Jörg Schorer; Bernd Strauss
Visual span and change detection in soccer: An expertise study Journal Article
In: Journal of Cognitive Psychology, vol. 23, no. 3, pp. 302–310, 2011.
There is evidence to suggest that sports experts are able to extract more perceptual information from a single fixation than novices when exposed to meaningful tasks that are specific to their field of expertise. In particular, Reingold et al. (2001) showed that chess experts use a larger visual span including fewer fixations when compared to their less skilled counterparts. The aim of the present study was to examine whether also in a more complex environment, namely soccer, skilled players use a larger visual span and fewer fixations than less skilled players when attempting to recognise players' positions. To this end, we combined the gaze-contingent window technique with the change detection paradigm. Results seem to suggest that skilled soccer players do not use a larger visual span than less skilled players. However, skilled soccer players showed significantly fewer fixations of longer duration than their less skilled counterparts, supporting the notion that experts may extract more information from a single glance.
Leandro Luigi Di Stasi; Adoración Antolí; José J. Cañas
Main sequence: An index for detecting mental workload variation in complex tasks Journal Article
In: Applied Ergonomics, vol. 42, no. 6, pp. 807–813, 2011.
The primary aim of this study was to validate the saccadic main sequence, in particular the peak velocity [PV], as an alternative psychophysiological measure of Mental Workload [MW]. Taking the Wickens' multiple resource model as the theoretical framework of reference, an experiment was conducted using the Firechieftextregisteredmicroworld. MW was manipulated by changing the task complexity (between groups) and the amount of training (within groups). There were significant effects on PV from both factors. These results provide additional empirical support for the sensitivity of PV to discriminate MW variation on visual-dynamic complex tasks. These findings and other recent results on PV could provide important information for the development of a new vigilance screening tool for the prevention of accidents in several fields of applied ergonomics.
Leandro Luigi Di Stasi; Adoración Antolí; Miguel Gea; José J. Cañas
A neuroergonomic approach to evaluating mental workload in hypermedia interactions Journal Article
In: International Journal of Industrial Ergonomics, vol. 41, no. 3, pp. 298–304, 2011.
Neuroergonomics could provide on-line methods for measuring mental effort while the operator interacts with hypermedia. We present an experimental study in which 28 participants interacted with a modified version of an existing Spanish e-commerce website in two searching tasks (Goal oriented shopping and Experiential shopping) that demand different amounts of cognitive resources. Mental workload was evaluated multidimensionally, using subjective rating, an interaction index, and eye-related indices. Eye movements and pupil diameter were recorded. The results showed visual scanning behaviour coincided with subjective test scores and performance data in showing a higher information processing load in Goal oriented shopping. However, pupil diameter was able to detect only the variation in user activation during the interaction task, a finding that replicates previous results on the validity of pupil size as an index of arousal. We conclude that a neuroergonomics approach could be a useful method for detecting variations in operators' attentional states. Relevance to industry: These results could provide important information for the development of a new attentional screening tool for the prevention of accidents in several application domains.
Leandro Luigi Di Stasi; D. Contreras; Antonio Cándido; José J. Cañas; A. Catena
Behavioral and eye-movement measures to track improvements in driving skills of vulnerable road users: First-time motorcycle riders Journal Article
In: Transportation Research Part F: Traffic Psychology and Behaviour, vol. 14, no. 1, pp. 26–35, 2011.
Motorcyclist deaths and injuries follow the trend in sales rather than in growth in the number of motorcycles, suggesting that fatalities are related to the lack of driver experience with recently purchased motorcycles. The aim of the present investigation was to assess the effects of experience and training in hazard perception. We compared first-time riders (people who are not yet riders/drivers) before and after training in six different riding scenarios to expert motorcycle riders. Thirty-three participants took part in the experiment. Volunteers rode a moped in a fixed-base virtual environment and were presented with a number of preset risky events. We used a multidimensional methodology, including behavioral, subjective and eye-movements data. The results revealed differences between experts and first-time riders, as well as the effect of training on the novice group. As expected, training led to an improvement in the riding skills of first-time riders, reducing the number of accidents, improving their capacity to adapt their speed to the situation, reducing trajectory-corrective movements, and changing their pattern of gaze exploration. We identified several behavioral and eye-related measures that are sensitive to both long-term experience and training in motorcycle riders. These findings will be useful for the design of on-line monitoring systems to evaluate changes in risk behavior and of programs for preventing and controlling risk behavior and improving situation awareness for novice riders, with the ultimate aim of reducing road-user mortality.
An exploration of visual behaviour in eyewitness identification tests Journal Article
In: Applied Cognitive Psychology, vol. 25, no. 2, pp. 244–254, 2011.
The contribution of internal (eyes, nose and mouth) and external (hair-line, cheek and jaw-line) features across eyewitness identification tests was examined using eye tracking. In Experiment 1, participants studied faces and were tested with lineups, either simultaneous (test faces presented in an array) or sequential (test faces presented one at a time). In Experiment 2, the recognition of previously studied faces was tested in a showup (a suspect face alone was presented). Results indicated that foils were analysed for a shorter period of time in the simultaneous compared to the sequential condition, whereas a positively identified face was analysed for a comparable period of time across lineup procedures. In simultaneous lineups and showups, a greater proportion of time was spent analysing internal features of the test faces compared to sequential lineups. Different decision processes across eyewitness identification tests are inferred based on the results.
Heather Flowe; Garrison W. Cottrell
An examination of simultaneous lineup identification decision processes using eye tracking Journal Article
In: Applied Cognitive Psychology, vol. 25, pp. 443–451, 2011.
Decision processes in simultaneous lineups (an array of faces in which a ‘suspect' face is displayed along with foil faces) were examined using eye tracking to capture the length and number oftimes that individual faces were visually analysed. The similarity of the lineup target face relative to the study face was manipulated, and face dwell times on the first visit and on return visits to the individual lineup faces were measured. On first visits, positively identified faces were examined for a longer duration compared to faces that were not identified. When no face was identified from the lineup, the suspect was visited for a longer duration compared to a foil face. On return visits, incorrectly identified faces were examined for a longer duration and visited more often compared to correctly identified faces. The results indicate that lineup decisions can be predicted by face dwell time and the number of visits made to faces.
Yu-feng Huang; Feng-yang Kuo
An eye-tracking investigation of internet consumers' decision deliberateness Journal Article
In: Internet Research, vol. 21, no. 5, pp. 541–561, 2011.
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.
Anke Huckauf; Mario H. Urbina
Object selection in gaze controlled systems: What you don't look at is what you get Journal Article
In: ACM Transactions on Applied Perception, vol. 8, no. 2, pp. 1–14, 2011.
Controlling computers using eye movements can provide a fast and efficient alternative to the computer mouse. However, implementing object selection in gaze-controlled systems is still a challenge. Dwell times or fixations on a certain object typically used to elicit the selection of this object show several disadvantages. We studied deviations of critical thresholds by an individual and task-specific adaptation method. This demonstrated an enormous variability of optimal dwell times. We developed an alternative approach using antisaccades for selection. For selection by antisaccades, highlighted objects are copied to one side of the object. The object is selected when fixating to the side opposed to that copy requiring to inhibit an automatic gaze shift toward new objects. Both techniques were compared in a selection task. Two experiments revealed superior performance in terms of errors for the individually adapted dwell times. Antisaccades provide an alternative approach to dwell time selection, but they did not show an improvement over dwell time. We discuss potential improvements in the antisaccade implementation with which antisaccades might become a serious alternative to dwell times for object selection in gaze-controlled systems.
Samuel B. Hutton; S. Nolte
The effect of gaze cues on attention to print advertisements Journal Article
In: Applied Cognitive Psychology, vol. 25, no. 6, pp. 887–892, 2011.
Print advertisements often employ images of humans whose gaze may be focussed on an object or region within the advertisement. Gaze cues are powerful factors in determining the focus of our attention, but there have been no systematic studies exploring the impact of gaze cues on attention to print advertisements. We tracked participants' eyes whilst they read an on-screen magazine containing advertisements in which the model either looked at the product being advertised or towards the viewer. When the model's gaze was directed at the product, participants spent longer looking at the product, the brand logo and the rest of the advertisement compared to when the model's gaze was directed towards the viewer. These results demonstrate that the focus of reader's attention can be readily manipulated by gaze cues provided by models in advertisements, and that these influences go beyond simply drawing attention to the cued area of the advertisement.
Eye movements reveal distinct search and reasoning processes in comprehension of complex graphs Journal Article
In: Applied Cognitive Psychology, vol. 25, no. 6, pp. 893–905, 2011.
Hierarchical graphs (e.g. file system browsers, family trees) represent objects (e.g. files, folders) as graph nodes, and relations (subfolder relations) between them as lines. In three experiments, participants viewed such graphs and carried out tasks that either required search for two target nodes (Experiment 1A), reasoning about their relation (Experiment 1B), or both (Experiment 2). We recorded eye movements and used the number of fixations in different phases to identify distinct stages of comprehension. Search in graphs proceeded like search in standard visual search tasks and was mostly unaffected by graph properties. Reasoning occurred typically in a separate stage at the end ofcomprehension and was affected by intersecting graph lines. The alignment ofnodes, together with linguistic factors, may also affect comprehension. Overall, there was good evidence to suggest that participants read graphs in a sequential manner, and that this is an economical approach of comprehension.
Haoxue Liu; Guangming Ding; Weihua Zhao; Hui Wang; Kaizheng Liu; Ludan Shi
Variation of drivers' visual features in long-tunnel entrance section on expressway Journal Article
In: Journal of Transportation Safety and Security, vol. 3, no. 1, pp. 27–37, 2011.
To avoid traffic accidents in long tunnel entrance sections, the authors studied the variation of driver's visual features based on real road experiments on the expressway. Drivers' visual feature parameters were recorded in real-time using Eyelink (eye tracking system) during the driving test. Mathematic models of drivers' fixation duration, the number of fixations, and saccade amplitude in tunnel entrance were established based on BP Neural Network (Error Back Propagation Network) simulation. Results showed that fixation duration increased gradually as the vehicle moving closer to the tunnel entrance, whereas the number of fixations and saccade amplitude decreased. Meanwhile, drivers' fixations shifted from straight ahead to the right side, which resulted in the number of fixations on the right side increased. After drivers entering the tunnel, fixation duration firstly decreased and then increased afterward, while the number of fixations and saccade amplitude kept increasing.
Mauro Marchitto; Leandro Luigi Di Stasi; José J. Cañas
Ocular movements under taskload manipulations: Influence of geometry on saccades in air traffic control simulated tasks Journal Article
In: Human Factors and Ergonomics in Manufacturing & Service Industries, vol. 19, no. 6, pp. 1–13, 2011.
Traffic geometry is a factor that contributes to cognitive complexity in air traffic control. In conflict-detection tasks, geometry can affect the attentional effort necessary to correctly perceive and interpret the situation; online measures of situational workload are therefore highly desirable. In this study, we explored whether saccadic movements vary with changes in geometry. We created simple scenarios with two aircraft and simulated a conflict detection task. Independent variables were the conflict angle and the distance to convergence point. We hypothesized lower saccadic peak velocity (and longer duration) for increasing complexity, that is, for increasing conflict angles and for different distances to convergence point. Response times varied accordingly with task complexity. Concerning saccades, there was a decrease of peak velocity (and a related increase of duration) for increased geometry complexity for large saccades (>15°). The data therefore suggest that geometry is able to influence "reaching" saccades and not "fixation" saccades.
Hideyuki Matsumoto; Yasuo Terao; Akihiro Yugeta; Hideki Fukuda; Masaki Emoto; Toshiaki Furubayashi; Tomoko Okano; Ritsuko Hanajima; Yoshikazu Ugawa
Where do neurologists look when viewing brain CT images? An eye-tracking study involving stroke cases Journal Article
In: PLoS ONE, vol. 6, no. 12, pp. e28928, 2011.
The aim of this study was to investigate where neurologists look when they view brain computed tomography (CT) images and to evaluate how they deploy their visual attention by comparing their gaze distribution with saliency maps. Brain CT images showing cerebrovascular accidents were presented to 12 neurologists and 12 control subjects. The subjects' ocular fixation positions were recorded using an eye-tracking device (Eyelink 1000). Heat maps were created based on the eye-fixation patterns of each group and compared between the two groups. The heat maps revealed that the areas on which control subjects frequently fixated often coincided with areas identified as outstanding in saliency maps, while the areas on which neurologists frequently fixated often did not. Dwell time in regions of interest (ROI) was likewise compared between the two groups, revealing that, although dwell time on large lesions was not different between the two groups, dwell time in clinically important areas with low salience was longer in neurologists than in controls. Therefore it appears that neurologists intentionally scan clinically important areas when reading brain CT images showing cerebrovascular accidents. Both neurologists and control subjects used the "bottom-up salience" form of visual attention, although the neurologists more effectively used the "top-down instruction" form.
Alberto Megías; Antonio Maldonado; Andrés Catena; Leandro Luigi Di Stasi; Jesús Serrano; Antonio Cándido
Modulation of attention and urgent decisions by affect-laden roadside advertisement in risky driving scenarios Journal Article
In: Safety Science, vol. 49, no. 10, pp. 1388–1393, 2011.
In road safety literature the effects of emotional content and salience of advertising billboards have been scarcely investigated. The main aim of this work was to uncover how affect-laden roadside advertisements can affect attention - eye-movements - and subsequent risky decisions - braking - on the Honda Riding Trainer motorcycle simulator. Results indicated that the number of fixations and total fixation time elicited by the negative and positive emotional advertisements were larger than the neutral ones. At the same time, negative pictures got later gaze disengagement than positive and neutral ones. This attentional capture results in less eye fixation times on the road relevant region, where the important driving events happen. Finally, the negative emotional valence advertisements sped up braking on subsequent risky situations. Overall results demonstrated how advertisements with emotional content modulate attention allocation and driving decisions in risky situations and might be helpful for designing roadside advertisements regulations and risk prevention programs.
Marcus R. Munafò; Nicole Roberts; Linda Bauld; Ute Leaonards
Plain packaging increases visual attention to health warnings on cigarette packs in non-smokers and weekly smokers but not daily smokers Journal Article
In: Addiction, vol. 106, pp. 1505–1510, 2011.
AIMS: To assess the impact of plain packaging on visual attention towards health warning information on cigarette packs. DESIGN: Mixed-model experimental design, comprising smoking status as a between-subjects factor, and package type (branded versus plain) as a within-subjects factor. SETTING: University laboratory. PARTICIPANTS: Convenience sample of young adults, comprising non-smokers (n = 15), weekly smokers (n = 14) and daily smokers (n = 14). MEASUREMENTS: Number of saccades (eye movements) towards health warnings on cigarette packs, to directly index visual attention. FINDINGS: Analysis of variance indicated more eye movements (i.e. greater visual attention) towards health warnings compared to brand information on plain packs versus branded packs. This effect was observed among non-smokers and weekly smokers, but not daily smokers. CONCLUSION: Among non-smokers and non-daily cigarette smokers, plain packaging appears to increase visual attention towards health warning information and away from brand information.
Andi K. Winterboer; Martin I. Tietze; Maria K. Wolters; Johanna D. Moore
The user model-based summarize and refine approach improves information presentation in spoken dialog systems Journal Article
In: Computer Speech and Language, vol. 25, no. 2, pp. 175–191, 2011.
A common task for spoken dialog systems (SDS) is to help users select a suitable option (e.g., flight, hotel, and restaurant) from the set of options available. As the number of options increases, the system must have strategies for generating summaries that enable the user to browse the option space efficiently and successfully. In the user-model based summarize and refine approach (UMSR, Demberg and Moore, 2006), options are clustered to maximize utility with respect to a user model, and linguistic devices such as discourse cues and adverbials are used to highlight the trade-offs among the presented items. In a Wizard-of-Oz experiment, we show that the UMSR approach leads to improvements in task success, efficiency, and user satisfaction compared to an approach that clusters the available options to maximize coverage of the domain (Polifroni et al., 2003). In both a laboratory experiment and a web-based experimental paradigm employing the Amazon Mechanical Turk platform, we show that the discourse cues in UMSR summaries help users compare different options and choose between options, even though they do not improve verbatim recall. This effect was observed for both written and spoken stimuli.
Chris M. R. Smerecnik; Ilse Mesters; Loes T. E. Kessels; Robert A. C. Ruiter; Nanne K. De Vries; Hein De Vries
Understanding the positive effects of graphical risk information on comprehension: Measuring attention directed to written, tabular, and graphical risk information Journal Article
In: Risk Analysis, vol. 30, no. 9, pp. 1387–1398, 2010.
Risk communications are an integral aspect of health education and promotion. However, the commonly used textual risk information is relatively difficult to understand for the average recipient. Consequently, researchers and health promoters have started to focus on so-called decision aids, such as tables and graphs. Although tabular and graphical risk information more effectively communicate risks than textual risk information, the cognitive mechanisms responsible for this enhancement are unclear. This study aimed to examine two possible mechanisms (i.e., cognitive workload and attention). Cognitive workload (mean pupil size and peak pupil dilation) and attention directed to the risk information (viewing time, number of eye fixations, and eye fixation durations) were both measured in a between-subjects experimental design. The results suggest that graphical risk information facilitates comprehension of that information because it attracts and holds attention for a longer period of time than textual risk information. Graphs are thus a valuable asset to risk communication practice for two reasons: first, they tend to attract attention and, second, when attended to, they elicit information extraction with relatively little cognitive effort, and finally result in better comprehension.
Matt Canham; Mary Hegarty
Effects of knowledge and display design on comprehension of complex graphics Journal Article
In: Learning and Instruction, vol. 20, no. 2, pp. 155–166, 2010.
In two experiments, participants made inferences from weather maps, before and after they received instruction about relevant meteorological principles. Different versions of the maps showed either task-relevant information alone, or both task-relevant and task-irrelevant information. Participants improved on the inference task after instruction, indicating that they could apply newly acquired declarative knowledge to make inferences from graphics. In Experiment 1, participants spent more time viewing task-relevant information and less time viewing task-irrelevant information after instruction, and in Experiment 2, the presence of task-irrelevant information impaired performance. These results show that domain knowledge can affect information selection and encoding from complex graphics as well as processes of interpreting and making inferences from the encoded information. They also provide validation of one principle for the design of effective graphical displays, namely that graphics should not display more information than is required for the task at hand.
Jean Carletta; Robin L. Hill; Craig Nicol; Tim Taylor; Jan Peter Ruiter; Ellen Gurman Bard
Eyetracking for two-person tasks with manipulation of a virtual world Journal Article
In: Behavior Research Methods, vol. 42, no. 1, pp. 254–265, 2010.
Eyetracking facilities are typically restricted to monitoring a single person viewing static images or pre-recorded video. In the present article, we describe a system that makes it possible to study visual attention in coordination with other activity during joint action. The software links two eyetracking systems in parallel and provides an on-screen task. By locating eye movements against dynamic screen regions, it permits automatic tracking of moving on-screen objects. Using existing SR technology, the system can also cross-project each participant's eyetrack and mouse location onto the other's on-screen work space. Keeping a complete record of eyetrack and on-screen events in the same format as subsequent human coding, the system permits the analysis of multiple modalities. The software offers new approaches to spontaneous multimodal communication: joint action and joint attention. These capacities are demonstrated using an experimental paradigm for cooperative on-screen assembly of a two-dimensional model. The software is available under an open source license.
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
In: PLoS ONE, vol. 5, no. 3, pp. e9710, 2010.
BACKGROUND: Glaucoma is a progressive eye disease and a leading cause of visual disability. Automated assessment of the visual field determines the different stages in the disease process: it would be desirable to link these measurements taken in the clinic with patient's actual function, or establish if patients compensate for their restricted field of view when performing everyday tasks. Hence, this study investigated eye movements in glaucomatous patients when viewing driving scenes in a hazard perception test (HPT). METHODOLOGY/PRINCIPAL FINDINGS: The HPT is a component of the UK driving licence test consisting of a series of short film clips of various traffic scenes viewed from the driver's perspective each containing hazardous situations that require the camera car to change direction or slow down. Data from nine glaucomatous patients with binocular visual field defects and ten age-matched control subjects were considered (all experienced drivers). Each subject viewed 26 different films with eye movements simultaneously monitored by an eye tracker. Computer software was purpose written to pre-process the data, co-register it to the film clips and to quantify eye movements and point-of-regard (using a dynamic bivariate contour ellipse analysis). On average, and across all HPT films, patients exhibited different eye movement characteristics to controls making, for example, significantly more saccades (P<0.001; 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.
Examining the validity of the Needleman-Wunsch algorithm in identifying decision strategy with eye-movement data Journal Article
In: Decision Support Systems, vol. 49, no. 4, pp. 396–403, 2010.
A new generation of eye trackers shows us a promising alternative approach to tracing decision processes beyond the popular computerized-information-board approach. In order to exploit the eye-movement data, this study examined the validity of the Needleman-Wunsch algorithm (NWA) to characterize the decision process, and proposed an NWA-based classification method to predict which typical strategy an empirical search behavior might belong to. An eye-tracking based experiment was conducted. Our results showed that the resemblance score by NWA conformed to the assumption that the pair of information search behaviors based on the same strategy should have the closest resemblance. Moreover, with respect to our NWA-based classification method, our result showed that its overall prediction accuracy, hit-ratio, in identifying underlying strategies achieved 88%, significantly much higher than that gained from chance. On the whole, the combination of eye-fixation data and our NWA-based classification method is qualified. textcopyright 2010 Elsevier B.V. All rights reserved.
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
In: Journal of Air Transport Management, vol. 16, no. 6, pp. 330–333, 2010.
To assess the effects of workload pressures, participants interacted with a modified version of air traffic control simulated tasks requiring different levels of cognitive resources. Changes in mental workload between the levels were evaluated multidimensionally using a subjective rating, performance in a secondary task, and other behavioural indices. Saccadic movements were measured using a video-based eye tracking system. The Wickens multiple resource model is used as a theoretical reference framework. Saccadic peak velocity decreases with increasing cognitive load, in agreement with subjective test scores and performance data. That saccadic peak velocity is sensitive to variations in mental workload during ecologically valid tasks is demonstrated.
Leandro Luigi Di Stasi; Rebekka Renner; Peggy Staehr; Jens R. Helmert; Boris M. Velichkovsky; Jose J. Canas; Andrés Catena; Sebastian Pannasch
Saccadic Peak Velocity Sensitivity to Variations in Mental Workload Journal Article
In: Aviation Space and Environmental Medicine, vol. 81, no. 4, pp. 413–417, 2010.
Introduction: For research and applications in the field of (neuro)ergonomics, it is of increasing importance to have reliable methods for measuring mental workload. In the present study we examined the hypothesis that saccadic eye movements can be used for an online assessment of mental workload. Methods: Saccadic main sequence (amplitude, dura- tion and peak velocity) was used as a diagnostic measure of mental workload in a virtual driving task with three complexity levels. We tested 18 drivers in the SIRCA driving simulator while their eye movements were recorded. The Wickens' multiple resources model was used as theoretical framework. Changes in mental workload between the complexity levels were evaluated multidimensionally, using subjective rating, performance in a secondary task, and other behavioral indices. Results: Saccadic peak velocity decreased (7.2 visual °/s) as the mental workload increased, as measured by scores of mental workload test (15.2 scores) and the increase of the reaction time on the secondary task (46 ms). Discussion: Saccadic peak velocity is affected by variations in mental workload during ecologically valid tasks. We conclude that saccadic peak velocity could be a useful diagnostic index for the assessment of operators' mental workload and attentional state in hazardous environments.
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
In: Journal of Experimental Psychology: Learning, Memory, and Cognition, vol. 36, no. 1, pp. 37–53, 2010.
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.
Constanze Hesse; Tristan T. Nakagawa; Heiner Deubel
Bimanual movement control is moderated by fixation strategies Journal Article
In: Experimental Brain Research, vol. 202, no. 4, pp. 837–850, 2010.
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.
Lynn Huestegge; Eva Maria Skottke; Sina Anders; Jochen Müsseler; Günter Debus
The development of hazard perception: Dissociation of visual orientation and hazard processing Journal Article
In: Transportation Research Part F: Traffic Psychology and Behaviour, vol. 13, no. 1, pp. 1–8, 2010.
Eye movements are a key behavior for visual information processing in traffic situations and for vehicle control. Previous research showed that effective ways of eye guidance are related to better hazard perception skills. Furthermore, hazard perception is reported to be faster for experienced drivers as compared to novice drivers. However, little is known whether this difference can be attributed to the development of visual orientation, or hazard processing. In the present study, we compared eye movements of 20 inexperienced and 20 experienced drivers in a hazard perception task. We separately measured (a) the interval between the onset of a static hazard scene and the first fixation on a potential hazard, and (b) the interval between the first fixation on a potential hazard and the final response. While overall RT was faster for experienced compared to inexperienced drivers, the scanning patterns revealed that this difference was due to faster processing after the initial fixation on the hazard, whereas scene scanning times until the initial fixation on the hazard did not differ between groups. textcopyright 2009 Elsevier Ltd. All rights reserved.
Kentaro Kotani; Yuji Yamaguchi; Takafumi Asao; Ken Horii
Design of eye-typing interface using saccadic latency of eye movement Journal Article
In: International Journal of Human-Computer Interaction, vol. 26, no. 4, pp. 361–376, 2010.
The objective of this study was to construct and empirically evaluate an improved, online eye-typing interface with respect to its practical usability. The system used the concept of saccadic latency, a silent period of 200 to 250 msec precedes the initiation of a saccade, for identifying the user's intentional text entry. Ten individuals participated in the experiment that was conducted on 2 consecutive days, with three blocks of trials conducted on each day. A block included five trials, each of which involved completing the text entry of a short sentence using this eye-typing interface. The proposed interface was evaluated by the user's performance based on indices including typing speed and an error index. For defining the error index, the overproduction rates (ORs) were used. The results showed an average OR of 0.032 and average typing speed of 27.1 characters typed per minute. The result revealed that the typing speed changed as an effect of participant, day, and block. The characteristics of the proposed interface with the related characteristics of an eye-typing interface were summarized to discuss a further study for the eye-typing interface.
Katja Meyer; Thorsten Rasch; Wolfgang Schnotz
Effects of animation's speed of presentation on perceptual processing and learning Journal Article
In: Learning and Instruction, vol. 20, no. 2, pp. 136–145, 2010.
Animations presented at different speed are assumed to differentially interact with learners' perception and cognition due to the constraints imposed by learners' limited sensitivity to incoming dynamic information. To investigate the effects of high and low presentation speed of animation, two studies were conducted. In Study 1, participants were 55 students who learned about the functioning of a four-stroke engine from an animation with user-controlled presentation speed. In Study 2, eye movements of 19 students were analysed for different system-controlled presentation speeds of animation. Results indicated that high presentation speeds accentuated global events (i.e., macro-events), whereas low speeds accentuated local events (i.e., micro-events). However, eye movements were primarily affected by the content rather than the presentation speed of animation.
Gerardo Cepeda Porras; Yann Gaël Guéhéneuc
An empirical study on the efficiency of different design pattern representations in UML class diagrams Journal Article
In: Empirical Software Engineering, vol. 15, no. 5, pp. 493–522, 2010.
Design patterns are recognized in the software engineering community as useful solutions to recurring design problems that improve the quality of programs. They are more and more used by developers in the design and implementation of their programs. Therefore, the visualization of the design patterns used in a program could be useful to efficiently understand how it works. Currently, a common representation to visualize design patterns is the UML collaboration notation. Previous work noticed some limitations in the UML representation and proposed new representations to tackle these limitations. However, none of these pieces of work conducted empirical studies to compare their new representations with the UML representation. We designed and conducted an empirical study to collect data on the performance of developers on basic tasks related to design pattern comprehension (i.e., identifying composition, role, participation) to evaluate the impact of three visual representations and to compare them with the UML one. We used eye-trackers to measure the developers' effort during the execution of the study. Collected data and their analyses show that stereotype-enhanced UML diagrams are more efficient for identifying composition and role than the UML collaboration notation. The UML representation and the pattern-enhanced class diagrams are more efficient for locating the classes participating in a design pattern (i.e., identifying participation).
Lee Richstone; Michael J. Schwartz; Casey Seideman; Jeffrey Cadeddu; Sandra P. Marshall; Louis R. Kavoussi
Eye metrics as an objective assessment of surgical skill Journal Article
In: Annals of Surgery, vol. 252, no. 1, pp. 177–182, 2010.
OBJECTIVE: Currently, surgical skills assessment relies almost exclusively on subjective measures, which are susceptible to multiple biases. We investigate the use of eye metrics as an objective tool for assessment of surgical skill. SUMMARY BACKGROUND DATA: Eye tracking has helped elucidate relationships between eye movements, visual attention, and insight, all of which are employed during complex task performance (Kowler and Martins, Science. 1982;215:997-999; Tanenhaus et al, Science. 1995;268:1632-1634; Thomas and Lleras, Psychon Bull Rev. 2007;14:663-668; Thomas and Lleras, Cognition. 2009;111:168-174; Schriver et al, Hum Factors. 2008;50:864-878; Kahneman, Attention and Effort. 1973). Discovery of associations between characteristic eye movements and degree of cognitive effort have also enhanced our appreciation of the learning process. METHODS: Using linear discriminate analysis (LDA) and nonlinear neural network analyses (NNA) to classify surgeons into expert and nonexpert cohorts, we examine the relationship between complex eye and pupillary movements, collectively referred to as eye metrics, and surgical skill level. RESULTS: Twenty-one surgeons participated in the simulated and live surgical environments. In the simulated surgical setting, LDA and NNA were able to correctly classify surgeons as expert or nonexpert with 91.9% and 92.9% accuracy, respectively. In the live operating room setting, LDA and NNA were able to correctly classify surgeons as expert or nonexpert with 81.0% and 90.7% accuracy, respectively. CONCLUSIONS: We demonstrate, in simulated and live-operating environments, that eye metrics can reliably distinguish nonexpert from expert surgeons. As current medical educators rely on subjective measures of surgical skill, eye metrics may serve as the basis for objective assessment in surgical education and credentialing in the future. Further development of this potential educational tool is warranted to assess its ability to both reliably classify larger groups of surgeons and follow progression of surgical skill during postgraduate training.
Jamal K. Mansour; R. C. L. Lindsay; Neil Brewer; Kevin G. Munhall
Characterizing visual behaviour in a lineup task Journal Article
In: Applied Cognitive Psychology, vol. 23, no. 7, pp. 1012–1026, 2009.
Eye tracking was used to monitor participants' visual behaviour while viewing lineups in order to determine whether gaze behaviour predicted decision accuracy. Participants viewed taped crimes followed by simultaneous lineups. Participants (N¼34) viewed 4 target-present and 4 target-absent lineups. Decision time, number of fixations and duration of fixations differed for selections vs. non- selections. Correct and incorrect selections differed only in terms of comparison-type behaviour involving the selected face. Correct and incorrect non-selections could be distinguished by decision time, number of fixations and duration of fixations on the target or most-attended face and comparisons. Implications of visual behaviour for judgment strategy (relative vs. absolute) are discussed.
Jason S. McCarley
Effects of speed - accuracy instructions on oculomotor scanning and target recognition in a simulated baggage X-ray screening task Journal Article
In: Ergonomics, vol. 52, no. 3, pp. 325–333, 2009.
Visual search tasks are often carried out under high levels of time stress. Transportation security screeners, for example, face demands to achieve high levels of accuracy while maintaining rapid passenger throughput. An experiment examined the strategies by which operators regulate visual search performance under such conditions. Observers performed a simulated baggage-screening task under instructions to emphasise either response speed or accuracy. Behavioural measures and eye movements were recorded. Observers made fewer and briefer fixations under emphasise-speed than under emphasise-accuracy instructions. Losses in accuracy were produced by more frequent failures to fixate on targets and a decrease in the detection rate of non-fixated targets. The likelihood with which observers detected a fixated target was similar across speed-accuracy instructions. Results will inform efforts to model visual search in naturalistic tasks, allowing more accurate prediction of response times and error rate and may aid the design of training programmes and other interventions to improve search performance under stress.
Michael Rohs; Robert Schleicher; Johannes Schöning; Georg Essl; Anja Naumann; Antonio Krüger
Impact of item density on the utility of visual context in magic lens interactions Journal Article
In: Personal and Ubiquitous Computing, vol. 13, no. 8, pp. 633–646, 2009.
This article reports on two user studies investi- gating the effect of visual context in handheld augmented reality interfaces.Adynamic peephole interface (without vi- sual context beyond the device display) was compared to a magic lens interface (with video see-through augmentation of external visual context). The task was to explore items on a map and look for a specific attribute. We tested dif- ferent sizes of visual context as well as different numbers of items per area, i.e. different item densities. Hand motion patterns and eye movements were recorded. We found that visual context is most effective for sparsely distributed items and gets less helpful with increasing item density. User per- formance in the magic lens case is generally better than in the dynamic peephole case, but approaches the performance of the latter the more densely the items are spaced. In all conditions, subjective feedback indicates that participants generally prefer visual context over the lack thereof. The insights gained from this study are relevant for designers of mobile AR and dynamic peephole interfaces, involving spa- tially tracked personal displays or combined personal and public displays, by suggesting when to use visual context.
Ladislao Salmerón; Thierry Baccino; José J. Cañas; Rafael I. Madrid; Inmaculada Fajardo
Do graphical overviews facilitate or hinder comprehension in hypertext? Journal Article
In: Computers and Education, vol. 53, no. 4, pp. 1308–1319, 2009.
Educational hypertexts usually include graphical overviews, conveying the structure of the text schematically with the aim of fostering comprehension. Despite the claims about their relevance, there is currently no consensus on the impact that hypertext overviews have on the reader's comprehension. In the present paper we have explored how hypertext overviews might affect comprehension with regard to (a) the time at which students read the overview and (b) the hypertext difficulty. The results from two eye-tracking studies revealed that reading a graphical overview at the beginning of the hypertext is related to an improvement in the participant's comprehension of quite difficult hypertexts, whereas reading an overview at the end of the hypertext is linked to a decrease in the student's comprehension of easier hypertexts. These findings are interpreted in light of the Assimilation Theory and the Active Processing model. Finally, the key educational and hypertext design implications of the results are discussed.
Oleg Špakov; Päivi Majaranta
Scrollable keyboards for casual eye typing Journal Article
In: PsychNology Journal, vol. 7, no. 2, pp. 159–173, 2009.
In eye typing, a full on-screen keyboard often takes a lot of space because the inaccuracy in eye tracking requires big keys. We propose “scrollable keyboards” where one or more rows are hidden to save space. Results from an experiment with 8 expert participants show that the typing speed reduced by 51.4% for a 1-row keyboard and 25.3% for a 2-row keyboard compared to a full (3-row) QWERTY. By optimizing the keyboard layout according to letter- to-letter probabilities we were able to reduce the scroll button usage, which further increased the typing speed from 7.26 wpm (QWERTY) to 8.86 wpm (optimized layout) on the 1-row keyboard, and from 11.17 wpm to 12.18 wpm on the 2-row keyboard, respectively
Åsa Wengelin; Mark Torrance; Kenneth Holmqvist; Sol Simpson; David Galbraith; Victoria Johansson; Roger Johansson
Combined eyetracking and keystroke-logging methods for studying cognitive processes in text production Journal Article
In: Behavior Research Methods, vol. 41, no. 2, pp. 337–351, 2009.
Writers typically spend a certain proportion of time looking back over the text that they have written. This is likely to serve a number of different functions, which are currently poorly understood. In this article, we present two systems, ScriptLog+ TimeLine and EyeWrite, that adopt different and complementary approaches to exploring this activity by collecting and analyzing combined eye movement and keystroke data from writers composing extended texts. ScriptLog+ TimeLine is a system that is based on an existing keystroke-logging program and uses heuristic, pattern-matching methods to identify reading episodes within eye movement data. EyeWrite is an integrated editor and analysis system that permits identification of the words that the writer fixates and their location within the developing text. We demonstrate how the methods instantiated within these systems can be used to make sense of the large amount of data generated by eyetracking and keystroke logging in order to inform understanding of the cognitive processes that underlie written text production.
Sauman Chu; Nora Paul; Laura Ruel
Using eye tracking technology to examine the effectiveness of design elements on news websites Journal Article
In: Information Design Journal, vol. 17, no. 1, pp. 31–43, 2009.
Online environments allow for a richer expression for certain design elements. The goal of this collaborative research project is to identify, design, and examine various online news features in order to determine the impact of different digital design combinations on news audiences. Eye tracking was the primary method we used to examine three main areas: navigation for slide shows, effectiveness of breaking news formats, and design options for supplemental links. The project used an applied research approach by taking academically rigorous research and using that to inform and guide industry practice. [ABSTRACT FROM AUTHOR] Copyright of Information Design Journal (IDJ) is the property of John Benjamins Publishing Co. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.
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
In: Transportation Research Part F: Traffic Psychology and Behaviour, vol. 12, no. 5, pp. 361–370, 2009.
We present data from an ongoing research project on the cognitive, emotional and neuropsychological basis of risk behaviour. The main aim of the project is to build a model of risk behaviour so that if we know certain cognitive, behavioural and emotional variables, we will be able to predict decisions made in the face of uncertainty and risk, with the final goal of designing programs for evaluating, preventing and controlling risk behaviour. The objective of the present study was to look for individual differences in hazard perception during a static riding simulation and their relationship with mental workload. We used a multidimensional methodology, including behavioural, subjective and physiological data. The behavioural measures were obtained in a static riding simulation during eight hazard situations. We evaluated whether eye activity measures correlated with cognitive workload and different types of risky behaviours. Eye movement parameters were measured using a video-based eye tracking system. We found that risk-prone individuals showed specific patterns of risky behaviours and that peak of saccadic velocity and subjective mental workload indexes were both reliable indicators of risk proneness. Mental workload was higher for participants showing attitudes to risk behaviours probably because of a lack of conscious awareness of specific cues indicating dangerous scenarios.
Yasuhiro Seya; Hidetoshi Nakayasu; Patrick Patterson
Visual search of trained and untrained drivers in a driving simulator Journal Article
In: Japanese Psychological Research, vol. 50, no. 4, pp. 242–252, 2008.
To investigate the effects of driving experience on visual search during driving, we measured eye movements during driving tasks using a driving simulator. We evaluated trained and untrained drivers for selected driving road section types (for example, intersections and straight roads). Participants in the trained group had received driving training by the simulator before the experiment, while the others had no driving training by it. In the experiment, the participants were instructed to drive safely in the simulator. The results of scan paths showed that eye positions were less variable in the trained group than in the untrained group. Total eye-movement distances were shorter, and fixation durations were longer in the trained group than in the untrained group. These results suggest that trained drivers may perceive relevant information efficiently with few eye movements by using their anticipation skills and useful field of view, which may have been developed through their driving training in the simulator.
Brian Sullivan; Jelena Jovancevic-Misic; Mary Hayhoe; Gwen Sterns
Use of multiple preferred retinal loci in Stargardt's disease during natural tasks: A case study Journal Article
In: Ophthalmic and Physiological Optics, vol. 28, no. 2, pp. 168–177, 2008.
Individuals with central visual field loss often use a preferred retinal locus (PRL) to compensate for their deficit. We present a case study examining the eye movements of a subject with Stargardt's disease causing bilateral central scotomas, while performing a set of natural tasks including: making a sandwich; building a model; reaching and grasping; and catching a ball. In general, the subject preferred to use PRLs in the lower left visual field. However, there was considerable variation in the location and extent of the PRLs used. Our results demonstrate that a well-defined PRL is not necessary to adequately perform this set of tasks and that many sites in the peripheral retina may be viable for PRLs, contingent on task and stimulus constraints.
Jens R. Helmert; Sebastian Pannasch; Boris M. Velichkovsky
Influences of dwell time and cursor control on the performance in gaze driven typing Journal Article
In: Journal of Eye Movement Research, vol. 2, no. 1, pp. 1–8, 2008.
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.
Keith Rayner; Brett Miller; Caren M. Rotello
Eye movements when looking at print advertisements: The goal of the viewer matters Journal Article
In: Applied Cognitive Psychology, vol. 22, no. 5, pp. 697–707, 2008.
Viewers looked at print advertisements as their eye movements were recorded. Half of them were asked to rate how much they liked each ad (for convenience, we will generally use the term 'ad' from this point on), while the other half were asked to rate the effectiveness of each ad. Previous research indicated that viewers who were asked to consider purchasing products in the ads looked at the text earlier and more often than the picture part of the ad. In contrast, viewers in the present experiment looked at the picture part of the ad earlier and longer than the text. The results indicate quite clearly that the goal of the viewer very much influences where (and for how long) viewers look at different parts of ads, but also indicate that the nature of the ad per se matters.
Michael L. Spezio; Po-Yin Samuel Huang; Fulvia Castelli; Ralph Adolphs
Amygdala damage impairs eye contact during conversations with real people Journal Article
In: Journal of Neuroscience, vol. 27, no. 15, pp. 3994–3997, 2007.
The role of the human amygdala in real social interactions remains essentially unknown, although studies in nonhuman primates and studies using photographs and video in humans have shown it to be critical for emotional processing and suggest its importance for social cognition. We show here that complete amygdala lesions result in a severe reduction in direct eye contact during conversations with real people, together with an abnormal increase in gaze to the mouth. These novel findings from real social interactions are consistent with an hypothesized role for the amygdala in autism and the approach taken here opens up new directions for quantifying social behavior in humans.
Yi-Fang Tsai; Erik Viirre; Christopher Strychacz; Bradley Chase; Tzyy-Ping Jung
Task performance and eye activity: Predicting behavior relating to cognitive workload Journal Article
In: Aviation Space and Environmental Medicine, vol. 78, no. 5, pp. B176–B185, 2007.
The focus of this study was to examine oculomotor behavioral changes while subjects performed auditory and driving tasks. There were 13 participants who completed 3 10-min tasks consisting of driving only, the Paced Auditory Serial Addition Task (PASAT) only, and a dual task of both driving and auditory tasks. For each participant, changes in six measures were assessed as a function of cognitive workload, specifically changes in eye activity, including blink frequency, blink duration, fixation frequency, fixation duration, pupil diameter, and horizontal vergence. In addition, deviations in lateral lane position were assessed as a measure of driving behavior. Compared with the subjects' behavior in the driving-only task, results showed an increase in blink frequency during the combined driving and auditory task. Also, during the dual task the mean pupil diameter and horizontal vergence increased when subjects performed well in the auditory task in contrast to when the subjects performed poorly. Evidence of visual tunneling or reduced range of scanning and decreases in rearview mirror and odometer glances appeared when subjects performed the driving and auditory dual task. There was no significant change in fixation frequency. However, decreased fixation duration appeared to predict upcoming errors in the auditory task. Pupil diameter changes were significantly higher when performing well on the auditory task than when subjects were performing poorly. Eye behavior trends reported in this study may provide insight to human behavior corresponding with cognitive workload, which may in turn be utilized to produce reliable workload indicators and applications that predict poor performance in real time.
Fernando Vilariño; Gerard Lacey; Jiang Zhou; Hugh Mulcahy; Stephen Patchett
Automatic labeling of colonoscopy video for cancer detection Journal Article
In: Pattern Recognition and Image Analysis, no. 1, pp. 290–297, 2007.
The labeling of large quantities of medical video data by clinicians is a tedious and time consuming task. In addition, the labeling process itself is rigid, since it requires the expert's interaction to classify image contents into a limited number of predetermined categories. This paper describes an architecture to accelerate the labeling step using eye movement tracking data. We report some initial results in training a Support Vector Machine (SVM) to detect cancer polyps in colonoscopy video, and a further analysis of their categories in the feature space using Self Organizing Maps (SOM). Our overall hypothesis is that the clinician's eye will be drawn to the salient features of the image and that sustained fixations will be associated with those features that are associated with disease states.
Michael W. Grünau; Kamala Pilgrim; Rong Zhou
Velocity discrimination thresholds for flowfield motions with moving observers Journal Article
In: Vision Research, vol. 47, no. 18, pp. 2453–2464, 2007.
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.
Jyun Cheng Wang; Rong-Fuh Day
The effects of attention inertia on advertisements on the WWW Journal Article
In: Computers in Human Behavior, vol. 23, no. 3, pp. 1390–1407, 2007.
When a viewer browses a web site, one presumably performs the task of seeking information from a sequence of scattered web pages to form a meaningful path. The aim of this study is to explore changes in the distribution of attention to banner advertisements as a viewer advances along a meaningful path and their effects on the advertisements. With aid of an instrument called eye-tracker, a laboratory experiment was conducted to observe directly the attention that subjects allocate along meaningful paths. Our results show that at different levels of depth in a meaningful path, the amount of attention allocated to the content of a web page is not the same, regardless of whether attention indexes were based on dwell time or the number of fixations. Theoretically, this experiment successfully generalizes the attentional inertia theory to web environment and elaborates web advertising research by involving a significant web structural factor. In practice, this findings hint that web advertising located in the earlier and later phases of a path should be priced higher than advertising in the middle phases because, during these two phases, the audience is more sensitive to the peripheral advertising.
A system for tracking gaze on handheld device Journal Article
In: Behavior Research Methods, vol. 38, no. 4, pp. 660–666, 2006.
Many of the current gaze-tracking systems require that a subject's head be stabilized and that the interface be fixed to a table. This article describes a prototype system for tracking gaze on the screen of mobile, handheld devices. The proposed system frees the user and the interface from previous constraints, allowing natural freedom of movement within the operational envelope of the system. The method is software-based, and integrates a commercial eye-tracking device (EyeLink I) with a magnetic positional tracking device (Polhemus FASTRAK). The evaluation of the system shows that it is capable of producing valid data with adequate accuracy.
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
In: Signal Processing: Image Communication, vol. 21, no. 7, pp. 531–549, 2006.
The ability to communicate remotely through the use of video as promised by wireless networks and already practised over fixed networks, is for deaf people as important as voice telephony is for hearing people. Sign languages are visual-spatial languages and as such demand good image quality for interaction and understanding. In this paper, we first analyse the sign language viewer's eye-gaze, based on the results of an eye-tracking study that we conducted, as well as the video content involved in sign language person-to-person communication. Based on this analysis we propose a sign language video coding system using foveated processing, which can lead to bit rate savings without compromising the comprehension of the coded sequence or equivalently produce a coded sequence with higher comprehension value at the same bit rate. We support this claim with the results of an initial comprehension assessment trial of such coded sequences by deaf users. The proposed system constitutes a new paradigm for coding sign language image sequences at limited bit rates. textcopyright 2006 Elsevier B.V. All rights reserved.
Eye and Pen: A new device for studying reading Journal Article
In: Behavior Research Methods, vol. 38, no. 2, pp. 287–299, 2006.
We present a new method for studying reading during writing and the relationships between these two activities. the Eye and Pen device makes a synchronous recording of handwriting and eye move- ments during written composition. it complements existing online methods by providing a fine-grained description of the visual information fixated during pauses as well as during the actual writing act. this device can contribute to the exploration of several research issues, since it can be used to investigate the role of the text produced so far and the documentary sources displayed in the task environment. the study of the engagement of reading during writing should provide important information about the dynamics of writing processes based on visual information. Written
David Crundall; Editha M. Loon; Geoffrey Underwood
Attraction and distraction of attention with roadside advertisements Journal Article
In: Accident Analysis and Prevention, vol. 38, no. 4, pp. 671–677, 2006.
The optimum positioning of roadside advertisements is recognized by the industry as an important factor in attracting the attention of passing drivers. Less acknowledged is the possibility that the location of an advertisement may distract attention from vital driving-related information. This study compared street-level advertisements (SLAs; predominantly bus shelters) with raised-level advertisements (RLAs) of the same size that were suspended 3 m above the ground, on their ability to attract attention under different task conditions. Participants were split into two groups and watched video clips of driving, rating them for hazardousness while their eye movements were recorded. One of the groups was additionally primed to attend to advertisements. SLAs received the most fixations when participants were solely looking for hazards, and the fewest fixations when primed to look for advertisements. Though SLAs also had longer fixations than the RLAs, they were more poorly recognized in a subsequent memory test. We conclude that SLAs attract and hold attention at inappropriate times compared to raised-level advertisements.
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
In: Psychology and Marketing, vol. 23, no. 5, pp. 369–382, 2006.
The role of peripheral flash advertisements in decision making as a distractor or a source of arousal was examined. Participants were asked to perform multiattribute decision making in a display envi- ronment with or without banners of advertisement flashing occasion- ally in the peripheral region of the display. The flash banners acceler- ated the speed of decision making, although the participants rarely made eye movements in response to the banners or fixated their eyes on them. It was interesting to note that the participants' pupil sizes increased with the presence of flash banners. These findings suggest that rather than distracting participants' attention, flash banners appear to elevate the general level of arousal of the participants, which in turn led to making faster on-line decisions.
David Crundall; Peter Chapman; Emma France; Geoffrey Underwood; Nicola Phelps
What attracts attention during police pursuit driving? Journal Article
In: Applied Cognitive Psychology, vol. 19, no. 4, pp. 409–420, 2005.
Efficient deployment of attention is important to the safe execution of tasks with a high content of visual information, such as driving. Chasing a lead vehicle is an extremely demanding and dangerous task, though little is known of the visual skills required. A study is reported that recorded the eye movements of police drivers and two control groups (novices and age- and experienced- matched controls) while watching a series of video clips of driving. The clips included pursuits, emergency response drives, and control drives (at normal speeds) around Nottinghamshire, UK. Analysis of gaze durations within certain categories of stimuli revealed that daytime pursuit drives correspond with an increase in gaze durations on a lead car (controlled for exposure), though police drivers direct their attention to other sources of potential hazards, such as pedestrians, more so than other drivers.
Peter Tarasewich; Marc Pomplun; Stephanie Fillion; Daniel Broberg
The enhanced restricted focus viewer Journal Article
In: International Journal of Human-Computer Interaction, vol. 19, no. 1, pp. 35–54, 2005.
The Enhanced Restricted Focus Viewer (ERFV) is a unique software tool for tracking the visual attention of users in hyperlinked environments, such as Web sites. The software collects data, such as mouse clicks along with the path of users' visual attention, as they browse a site. Unlike traditional eye-tracking procedures, the ERFV requires no hardware to operate other than a personal computer. In addition to time and cost savings, the ERFV allows the administration of usability testing to groups of participants simultaneously. A laboratory test comparing the ERFV to a hardware-based eye-tracking system showed that the two methods compared favorably in terms of how well they track a user's visual attention. The value of the ERFV as a usability testing tool was demonstrated through an experiment that evaluated two Web sites that were equivalent in content but that differed in terms of design. Although several open issues concerning the ERFV still remain, some of these issues are being addressed through ongoing research efforts.