Validity of low-resolution eye-tracking to assess eye movements during a rapid number naming task: performance of the eyetribe eye tracker

Optokinetic nystagmus (OKN) is an involuntary eye movement induced by motion of a large proportion of the visual field. It consists of a “slow phase (SP)” with eye movements in the same direction as the movement of the pattern and a “fast phase (FP)” with saccadic eye movements in the opposite direction. Study of OKN can reveal valuable information in ophthalmology, neurology and psychology. However, the current commercially available high-resolution and research-grade eye tracker is usually expensive. Methods & Results: We developed a novel fast and effective system combined with a low-cost eye tracking device to accurately quantitatively measure OKN eye movement. Conclusions: The experimental results indicate that the proposed method achieves fast and promising results in comparisons with several traditional approaches.

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Eye tracking in the wild: Piloting a real-life assessment paradigm for older adults

Journal of Eye Movement Research ◽

10.16910/jemr.12.1.4 ◽

2019 ◽

Vol 12 (1) ◽

Author(s):

Damaris Aschwanden ◽

Nicolas Langer ◽

Mathias Allemand

Keyword(s):

Older Adults ◽

Eye Movements ◽

Eye Tracking ◽

Personality Traits ◽

Feasibility Study ◽

Real Life ◽

Life Assessment ◽

Grocery Shopping ◽

Eye Tracker ◽

Older Individuals

Previous research showed associations between personality traits and eye movements of young adults in the laboratory. However, less is known about these associations in real life and in older age. Primarily, there seems to be no paradigm to assess eye movements of older adults in real life. The present feasibility study thus aimed to test grocery shopping as a real-life assessment paradigm with older adults. Additionally, possible links between personality traits and eye movements were explored. The sample consisted of 38 older individuals (M = 72.85 years). Participants did their grocery shopping in a supermarket while wearing an eye tracker. Three key feasibility issues were examined, that is (1) wearability of the eye tracker during grocery shopping, (2) recording, and (3) evaluation of eye movements in a real-life context. Our real-life assessment paradigm showed to be feasible to implement and acceptable to older adults. This feasibility study provides specific practical recommendations which may be useful for fu-ture studies that plan to innovatively expand the traditional methods repertoire of personality science and aging research by using eye tracking in real life.

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Is the eye-movement field confused about fixations and saccades? A survey among 124 researchers

Royal Society Open Science ◽

10.1098/rsos.180502 ◽

2018 ◽

Vol 5 (8) ◽

pp. 180502 ◽

Cited By ~ 35

Author(s):

Roy S. Hessels ◽

Diederick C. Niehorster ◽

Marcus Nyström ◽

Richard Andersson ◽

Ignace T. C. Hooge

Keyword(s):

Eye Movements ◽

Eye Tracking ◽

Coordinate System ◽

Eye Movement ◽

Eye Tracker ◽

New Methods ◽

Research Fields ◽

Wide Range ◽

Movement Field ◽

Mobile Eye Tracking

Eye movements have been extensively studied in a wide range of research fields. While new methods such as mobile eye tracking and eye tracking in virtual/augmented realities are emerging quickly, the eye-movement terminology has scarcely been revised. We assert that this may cause confusion about two of the main concepts: fixations and saccades. In this study, we assessed the definitions of fixations and saccades held in the eye-movement field, by surveying 124 eye-movement researchers. These eye-movement researchers held a variety of definitions of fixations and saccades, of which the breadth seems even wider than what is reported in the literature. Moreover, these definitions did not seem to be related to researcher background or experience. We urge researchers to make their definitions more explicit by specifying all the relevant components of the eye movement under investigation: (i) the oculomotor component: e.g. whether the eye moves slow or fast; (ii) the functional component: what purposes does the eye movement (or lack thereof) serve; (iii) the coordinate system used: relative to what does the eye move; (iv) the computational definition: how is the event represented in the eye-tracker signal. This should enable eye-movement researchers from different fields to have a discussion without misunderstandings.

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Collaborative Use of a Shared System Interface: The Role of User Gaze—Gaze Convergence Index Based on Synchronous Dual-Eyetracking

Applied Sciences ◽

10.3390/app10134508 ◽

2020 ◽

Vol 10 (13) ◽

pp. 4508 ◽

Cited By ~ 1

Author(s):

Armel Quentin Tchanou ◽

Pierre-Majorique Léger ◽

Jared Boasen ◽

Sylvain Senecal ◽

Jad Adam Taher ◽

...

Keyword(s):

Eye Movements ◽

Eye Tracking ◽

Task Performance ◽

Tracking Data ◽

Nomological Network ◽

Practical Applications ◽

The Gaze ◽

Research Perspectives ◽

System Interfaces

Gaze convergence of multiuser eye movements during simultaneous collaborative use of a shared system interface has been proposed as an important albeit sparsely explored construct in human-computer interaction literature. Here, we propose a novel index for measuring the gaze convergence of user dyads and address its validity through two consecutive eye-tracking studies. Eye-tracking data of user dyads were synchronously recorded while they simultaneously performed tasks on shared system interfaces. Results indicate the validity of the proposed gaze convergence index for measuring the gaze convergence of dyads. Moreover, as expected, our gaze convergence index was positively associated with dyad task performance and negatively associated with dyad cognitive load. These results suggest the utility of (theoretical or practical) applications such as synchronized gaze convergence displays in diverse settings. Further research perspectives, particularly into the construct’s nomological network, are warranted.

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The influence of vergence facility on binocular eye movements during reading

Journal of Eye Movement Research ◽

10.16910/jemr.12.4.9 ◽

2019 ◽

Vol 12 (4) ◽

Author(s):

Remo Poffa ◽

Roland Joos

Keyword(s):

Eye Movements ◽

Eye Tracking ◽

Reading Difficulties ◽

Eye Tracker ◽

Fixation Disparity ◽

Linear Mixed Effects ◽

Eye Movements During Reading ◽

Distance Conditions ◽

Reading Distance ◽

Binocular Coordination

Optometrists regularly use binocular measurements in patients with asthenopic complaints when performing close-up work. The focus of this work was therefore on the correlation of optometric parameters and objective fixation disparity (FD) measured by an eye tracker. In our investigation, 20 participants (6 male, 14 female) were subjected to a classical optometric procedure. Subsequently, these subjects read various sentences on a screen and eye movements were registered by using a RED500 eye tracker. The experiment was performed under two reading distance conditions. In order to be comparable with previous work, the present study was conducted under dark illumination conditions (J. A. Kirkby, Blythe, Drieghe, Benson, & Liversedge, 2013). FD values were deduced from objective eye tracking data during reading. Data analysis was done using linear mixed-effects models. FD was found to depend on vergence facility (t=3.3, p=0.004). Subjects with a low vergence facility showed more eso fixation disparity than subjects with a normal vergence facility. If studies of binocular coordination using eye tracking methods are performed under dark illumination conditions, vergence facility is an important parameter and should be accounted for. Neglecting this parameter may mask other important parameters. Vergence facility in context of reading difficulties may be important.

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Evaluating Eye Tracking Technology for Understanding how Medical Students Interpret a 12-Lead Electrocardiogram: A Quantitative Approach (Preprint)

10.2196/preprints.26675 ◽

2020 ◽

Author(s):

Mohammed Tahri Sqalli ◽

Dena Al-Thani ◽

Mohamed Badreldin Elshazly ◽

‪Mohammed Al-Hijji

Keyword(s):

Eye Movements ◽

Medical Students ◽

Eye Tracking ◽

Fixation Time ◽

Eye Tracker ◽

Different Types ◽

Interpretation Process ◽

The Mean ◽

Tracking Technology ◽

Insight Into

BACKGROUND It is common among healthcare practitioners that accurate interpretation of a 12-lead electrocardiogram demands high levels of skill and expertise. There is a variation amongst healthcare practitioners in their ability to read ECGs accurately and quickly. Moreover, guidelines or best-practices for a standard interpretation process are inexistant. This causes a chasm between skilled interpreters and medical students who are just beginning to develop this skill. OBJECTIVE This study aims to use the eye tracking methodology to research whether eye fixation can be used to gain a deeper understanding into how medical students acquire the ECG interpretation skill. METHODS Each one of the sixteen recruited medical students was asked to interpret ten different types of 12-lead ECGs, while their eye movements were recorded using a Tobii X60 eye tracker. The device uses corneal reflection technology to non-intrusively record the interpreter’s eye movements. The frequency of sampling is 60Hz. Fixations’ heatmaps of where medical students looked at were generated from the collected dataset. A statistical analysis was conducted on the fixations’ count and duration using the Mann Whitney U test, and the Kruskal Wallis test. RESULTS A total number of 16 medical students interpreting 10 ECGs each were recorded. Each interpretation lasted for a duration of 30 seconds. The mean accuracy of the interpretations was 55.63% with a standard deviation of 4.63 %. After analyzing the average fixation duration, we find that on average students study the three lower leads (rhythm strips) the most with a top-down approach (lead II has highest fixation time (mean = 2727 ms, SD = 456) followed by leads V1 (mean = 1476 fixations, SD = 320), V5 (mean = 1301 fixations, SD = 236). We also find a strong correlation between some of the eye tracking features like the time spent fixating and the fixation count (r = 0.87). Finally, by analyzing the time to the first fixation, we understand that medical students develop a personal system of interpretation that adapts and reacts to the nature and the complexity of the diagnosis. We also find that medical students consider some leads as their guiding point towards finding a hint leading to the correct interpretation. CONCLUSIONS The use of eye tracking methodology provided a more precise insight into how medical students learn how to interpret a 12-lead ECG. CLINICALTRIAL NA

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Using Saccadic Intrusions to Quantify Mental Workload

Proceedings of the Human Factors and Ergonomics Society Annual Meeting ◽

10.1177/154193120905301210 ◽

2009 ◽

Vol 53 (12) ◽

pp. 809-813 ◽

Cited By ~ 2

Author(s):

Satoru Tokuda ◽

Evan Palmer ◽

Edgar Merkle ◽

Alex Chaparro

Keyword(s):

Eye Movements ◽

Task Performance ◽

Task Difficulty ◽

Pupil Diameter ◽

Mental Workload ◽

Primary Task ◽

Strongly Correlated ◽

Eye Tracker ◽

Saccadic Intrusions ◽

Back Task

This study proposes a new method to quantify mental workload (MWL) automatically, without interfering with the operator's primary task performance. An unobtrusive Tobii eye tracker recorded eye movements while participants were engaged in a cognitively demanding N-back task. Original algorithms automatically analyzed the eye data, detected specific eye deviation movements called saccadic intrusions (SIs), and automatically quantified the eye deviation accounted for SIs. This SI measure was strongly correlated with the task difficulty levels in the N-back tasks and with pupil diameter. This indicates that the SI measure appeared to reflect MWL and may be used as a measure of MWL.

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Fixation Duration and Pupil Size as Diagnostic Tools in Parkinson’s Disease

Journal of Parkinson s Disease ◽

10.3233/jpd-202427 ◽

2021 ◽

pp. 1-11

Author(s):

Panagiota Tsitsi ◽

Mattias Nilsson Benfatto ◽

Gustaf Öqvist Seimyr ◽

Olof Larsson ◽

Prof Per Svenningsson ◽

...

Keyword(s):

Parkinson’S Disease ◽

Parkinson's Disease ◽

Eye Movements ◽

Eye Tracking ◽

Eye Movement ◽

Pupil Size ◽

Clinical Investigation ◽

Sampling Rate ◽

Diagnostic Tools ◽

Eye Tracker

Background: Visual and oculomotor problems are very common in Parkinson’s disease (PD) and by using eye-tracking such problems could be characterized in more detail. However, eye-tracking is not part of the routine clinical investigation of parkinsonism. Objective: To evaluate gaze stability and pupil size in stable light conditions, as well as eye movements during sustained fixation in a population of PD patients and healthy controls (HC). Methods: In total, 50 PD patients (66% males) with unilateral to mild-to-moderate disease (Hoehn & Yahr 1– 3, Schwab and England 70– 90% ) and 43 HC (37% males) were included in the study. Eye movements were recorded with Tobii Pro Spectrum, a screen-based eye tracker with a sampling rate of 1200 Hz. Logistic regression analysis was applied to investigate the strength of association of eye-movement measures with diagnosis. Results: Median pupil size (OR 0.811; 95% CI 0.666– 0.987; p = 0.037) and longest fixation period (OR 0.798; 95% CI 0.691-0.921; p = 0.002), were the eye-movement parameters that were independently associated with diagnosis, after adjustment for sex (OR 4.35; 95% CI 1.516– 12.483; p = 0.006) and visuospatial/executive score in Montreal Cognitive Assessment (OR 0.422; 95% CI 0.233– 0.764; p = 0.004). The area under the ROC curve was determined to 0.817; 95% (CI) 0.732– 0.901. Conclusion: Eye-tracking based measurements of gaze fixation and pupil reaction may be useful biomarkers of PD diagnosis. However, larger studies of eye-tracking parameters integrated into the screening of patients with suspected PD are necessary, to further investigate and confirm their diagnostic value.

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Eye-tracking analysis of leafy vegetables

Review on Agriculture and Rural Development ◽

10.14232/rard.2017.1-2.32-37 ◽

2018 ◽

Vol 6 (1-2) ◽

pp. 32-37

Author(s):

Ildikó Fruzsina Boros ◽

László Sipos ◽

Attila Gere

Keyword(s):

Decision Making ◽

Eye Movements ◽

Visual Attention ◽

Eye Tracking ◽

Leafy Vegetables ◽

Decision Making Process ◽

Final Decision ◽

Consumer Decision Making ◽

Eye Tracker ◽

Scientific Publications

There is a great supply of leafy vegetables on the market; hence capturing consumer’s attention (and decision) is critically important. Several scientific publications deal with consumer choices and the newest technology to capture consumer attention is eye-tracking. Eye-trackers are commonly used in Western Europe and Asia also, where it is an important and widely-used tool during product developments and the creation of marketing strategies. In Hungary, there are only a few publications about eye-tracking applications in vegetable growing and food industry. In our research, photographs about sorrel, lamb lettuce, spinach, leaf lettuce and dandelion leafs were analysed by eye-tracking technology and the eye movements of the participants during their decision making process of leafy vegetables were captured and evaluated. The eye-tracking analyses were carried out in the Sensory Laboratory of the Faculty of Food Sciences of Szent István University, using a Tobii X2-60 eye-tracker and Tobii Studio (version 3.0.5, Tobii Technology AB, Sweden) software. We aimed to answer the following research questions: Are there any connections between the eye movements of participants and their decisions? What amount of visual attention can be registered during the decision making process? Furthermore, the following metrics were measured and evaluated: fixation durations on the leafy vegetables, number of returns to products, pathways of visual attention, time until the final decision making and motivation of their final decisions. Measurement of the subconscious consumer decision making processes is way easier using eye-trackers compared to the traditional questionnaire-based methods, because it is hard or impossible to control our eye movements. Eye-tracking can be used successfully for understanding the expectations and decisions of the consumers.

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Using an Eye Tracker to Measure Information Processing According to Need for Cognition Level

Social Behavior and Personality An International Journal ◽

10.2224/sbp.7316 ◽

2018 ◽

Vol 46 (11) ◽

pp. 1869-1880 ◽

Cited By ~ 1

Author(s):

Di Wu ◽

Yuntao Gao ◽

Danmin Miao

Keyword(s):

Information Processing ◽

Eye Movements ◽

Eye Tracking ◽

Cognitive Processes ◽

Fixation Duration ◽

Reading Speed ◽

Need For Cognition ◽

Eye Tracker ◽

Persuasive Messages ◽

Tracking Technology

The need for cognition (NC) refers to the tendency for people to vary in the extent to which they engage in, and enjoy, cognitively effortful activities. However, few studies on NC have been conducted to investigate cognitive processes by using eye-tracking technology. Thus, we measured differences in eye movement between individuals high versus low in NC. We presented 43 undergraduates with persuasive messages on postponed retirement. Meanwhile, their eye movements were recorded using eye-tracking technology. Additionally, participants completed measures of attitude and recall of arguments. Our findings showed that participants high in NC recalled more arguments but did not form more favorable attitudes than did those low in NC. Furthermore, compared to those low in NC, those with high NC recorded longer eye fixation duration, more fixations, slower reading speed, and shorter saccade (movement) lengths. Finally, there were no differences between the two groups concerning the distribution (short, medium, and long fixations) and the proportion of regressions. Eye-tracking technology contributes to further understanding of characteristics of individuals high versus low in NC during reading.

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