Eye Tracking Research Articles

Retinal "sweet spot" for myopia treatment.

We studied which retinal area controls short-term axial eye shortening when human subjects were exposed to + 3.0D monocular defocus. A custom-built infrared eye tracker recorded the point of fixation while subjects watched a movie at a 2m distance. The eye tracker software accessed each individual movie frame in real-time and covered the points of fixation in the movie with a uniform grey patch. Four patches were programmed: (1) foveal patch (0-3 degrees), (2) annular patch (3-9deg), (3) foveal patch (0-3deg) combined with an annular patch (6-9deg), and (4) full-field patch where only 6-10deg were exposed to the defocus. Axial eye shortening was elicited similarly with full-field positive defocus and with the foveal patch, indicating that the fovea made only a minor contribution (-11 ± 12μm vs. -14 ± 17μm, respectively, n.s.). In contrast, patching a 3-9 degrees annular area or fovea together with an annular area of 6-9 degrees, completely suppressed the effect when compared with full-field defocus (+ 3 ± 1μm or -2 ± 13μm vs. -11 ± 12μm, respectively, p < 0.001). Finally, we found that the near-peripheral retina (6-10 degrees) is a "sweet spot" for positive defocus detection and alone can regulate eye growth control mechanism, and perhaps long-term refractive development (-9 ± 8μm vs. full-field: -11 ± 12μm, n.s.).

A Study on the Visual Perception of Cultural Value Characteristics of Traditional Southern Fujian Architecture Based on Eye Tracking

The traditional Southern Fujian architecture serves as a reflection of the region’s deeply rooted cultural values. However, research on the architectural and cultural heritage of Southern Fujian remains scarce. Accordingly, this study employs eye-tracking technology to experiment with 20 individuals with local cultural backgrounds and 20 without it to investigate the differences in the perception of the architectural heritage of Southern Fujian by individuals with disparate cultural backgrounds. The findings indicate that distinct groups evince disparate visual perceptions of the architectural and cultural heritage of Southern Fujian. The participants’ attention was divided into two categories: patterns and shapes and calligraphy and text. Non-locals were primarily drawn to patterns and shapes, whereas locals demonstrated a greater interest in the calligraphy and text category. The extraction of cultural information from calligraphic characters requires greater understanding and more time spent within the culture. Knowledge of local cultural backgrounds is helpful to better understand such information. This highlights the potential impact of Southern Fujian architecture on the local population. These findings provide a compelling rationale for the incorporation of multicultural elements in contemporary architectural design while also advocating for the preservation and advancement of Southern Fujian architectural heritage.

Guideline Daily Amount (GDA) outperforms Nutri-Score in assessing healthiness. Case study with breakfast cereals

AbstractNutritional information on packaging is becoming increasingly important in the food industry. Currently, labels are seen not only on the back of the packaging but also on the front. As there are many versions of front-of-pack labels (FoPLs), the research aims to determine which helps consumers the most in making decisions about which food to include in a healthier lifestyle. Nutri-Score, Guideline Daily Amount (GDA) and Multiple Traffic Lights (MTL) FoPLs on cereals were compared using eye-tracking (ET) and choice-based conjoint analysis (CBCA). CBCA was used to assess consumer preferences and the labels and products were also ranked. Based on the results, GDA type FoPL proved to be the most useful based on conjoint analysis, ranking and the analysis of ET parameters. This label helped participants the most in choosing the product that best fits into a healthier lifestyle. The Nutri-Score label, which offers little information on a product's nutritional content, was not favourably received by the Hungarian sample, who preferred more detailed FoP labels.

The Trail Making Test in Virtual Reality (TMT-VR): The Effects of Interaction Modes and Gaming Skills on Cognitive Performance of Young Adults

Virtual Reality (VR) is increasingly used in neuropsychological assessments due to its ability to simulate real-world environments. This study aimed to develop and evaluate the Trail Making Test in VR (TMT-VR) and investigate the effects of different interaction modes and gaming skills on cognitive performance. A total of 71 young female and male adults (aged 18–35) with high and low gaming skills participated in this study. Participants completed the TMT-VR using three interaction modes as follows: eye-tracking, head movement, and controller. Performance metrics included task completion time and accuracy. User experience, usability, and acceptability of TMT-VR were also examined. Results showed that both eye tracking and head movement modes significantly outperformed the controller in terms of task completion time and accuracy. No significant differences were found between eye tracking and head movement modes. Gaming skills did not significantly influence task performance using any interaction mode. The TMT-VR demonstrates high usability, acceptability, and user experience among participants. The findings suggest that VR-based assessments can effectively measure cognitive performance without being influenced by prior gaming skills, indicating potential applicability for diverse populations.

When noise becomes signal: a study of blink rate using an eye tracker

PurposeAlthough blink rate is considered important for digital eye strain and dry eye conditions, its assessment has been mostly manual. This study aimed at quantifying blink rate automatically using the Eyelink 1000 Plus eye tracker and comparing it with manual counting. Additionally, blink rate was correlated with reading eye movements and reading speed. MethodsThirty participants (mean age 26.8±3.5 years; 19 females) were enrolled. An on-screen reading task for 3 minutes duration, was repeated 3 times with a 2-minute break between the repetitions. During this task, eye movements and blinks were measured through the Eyelink 1000 Plus eye tracker. The blink was also counted manually by the examiner in real time from a video feed. ResultsThe blink rate obtained by the eye tracker (median [Q1, Q3]:11.7 [6.8,15.5] blinks/min) and manual counting (11.6 [7.1, 15.4] blinks/min) were comparable (p>0.5). No significant correlations were observed between the blink rate and any of the reading eye movement parameters except saccadic amplitude (Spearman's rho, rs =0.506). No statistically significant correlation was found between the blink rate and reading speed. ConclusionThe Eyelink 1000 Plus eye tracker gives a comparable blink rate compared to that obtained through manual counting. A positive correlation between the blink rate and saccade amplitude could indicate a coupled interaction between the two mechanisms to minimize visual loss during reading. The option of using this tracker to investigate blinks in dry eye and binocular vision disorders can be further explored.

Online Eye Tracking for Aphasia: A Feasibility Study Comparing Web and Lab Tracking and Implications for Clinical Use.

Studies using eye-tracking methodology have made important contributions to the study of language disorders such as aphasia. Nevertheless, in clinical groups especially, eye-tracking studies often include small sample sizes, limiting the generalizability of reported findings. Online, webcam-based tracking offers a potential solution to this issue, but web-based tracking has not been compared with in-lab tracking in past studies and has never been attempted in groups with language impairments. Patients with post-stroke aphasia (n=16) and age-matched controls (n=16) completed identical sentence-picture matching tasks in the lab (using an EyeLink system) and on the web (using WebGazer.js), with the order of sessions counterbalanced. We examined whether web-based eye tracking is as sensitive as in-lab eye tracking in detecting group differences in sentence processing. Patients were less accurate and slower to respond to all sentence types than controls. Proportions of gazes to the target and foil picture were computed in 100ms increments, which showed that the two modes of tracking were comparably sensitive to overall group differences across different sentence types. Web tracking showed comparable fluctuations in gaze proportions to target pictures to lab tracking in most analyses, whereas a delay of approximately 500-800ms appeared in web compared to lab data. Web-based eye tracking is feasible to study impaired language processing in aphasia and is sensitive enough to detect most group differences between controls and patients. Given that validations of webcam-based tracking are in their infancy and how transformative this method could be to several disciplines, much more testing is warranted.

Gaze-Contingent Layered Optical See-Through Displays with a Confidence-Driven View Volume.

The vergence-accommodation conflict (VAC) presents a major perceptual challenge for head-mounted displays with a fixed image plane. Varifocal and layered display designs can mitigate the VAC. However, the image quality of varifocal displays is affected by imprecise eye tracking, whereas layered displays suffer from reduced image contrast as the distance between layers increases. Combined designs support a larger workspace and tolerate some eye-tracking error. However, any layered design with a fixed layer spacing restricts the amount of error compensation and limits the in-focus contrast. We extend previous hybrid designs by introducing confidence-driven volume control, which adjusts the size of the view volume at runtime. We use the eye tracker's confidence to control the spacing of display layers and optimize the trade-off between the display's view volume and the amount of eye tracking error the display can compensate. In the case of high-quality focus point estimation, our approach provides high in-focus contrast, whereas low-quality eye tracking increases the view volume to tolerate the error. We describe our design, present its implementation as an optical-see head-mounted display using a multiplicative layer combination, and present an evaluation comparing our design with previous approaches.

Awareness support in collaborative programming tools: An evaluation based on programmer's perception and eye tracking

Groupware technology is an essential asset for organizations and a successful medium to support social meetings and teacher-learning processes when people are geographically distributed. Computer programming is a domain that can take advantage of the Collaborative Work paradigm and of this technology. However, to be truly effective, groupware systems must provide suitable awareness support, i.e., be capable of informing users of the activity taking place and of the team outcome, so that they can build a setting for their work. The study of awareness mechanisms and their influence on collaborative programming processes is an open research question. In this context, this article contributes an experimental study to evaluate the mechanisms to support coordination, communication, and awareness of COLLECE, a distributed group programming system rich in awareness support. This study brings as a novel approach the combination of subjective and objective information sources, specifically eye tracking techniques, and incorporates a heuristic evaluation of awareness support based on a well-known framework. Thanks to this experiment, we have been able to verify that this blended approach, in which users participate intensively, provides a more comprehensive and deeper assessment of awareness and other coordination and communication mechanisms, and thus a better understanding of how their use can influence the collaborative programming process and outcome (program or piece of software). The study has revealed strengths, weaknesses and opportunities for improvement of the evaluated system, and has yielded concrete results as to which are the most useful awareness components of the user interface not related to the activity supported by the system (programming), these being the traffic lights; the easiest to use, such as the session panel; or the components that impose a greater cognitive load, such as the multi-scrollbar. Regarding the relationship between the supported awareness dimensions and the quality of the collaboration outcome (computer program), the results point to the need to adequately support the What-Artifact dimension, i.e., highlighting in which part of the shared workspace (the source code) the user with floor control is working.

Classification of Internal and External Distractions in an Educational VR Environment Using Multimodal Features.

Virtual reality (VR) can potentially enhance student engagement and memory retention in the classroom. However, distraction among participants in a VR-based classroom is a significant concern. Several factors, including mind wandering, external noise, stress, etc., can cause students to become internally and/or externally distracted while learning. To detect distractions, single or multi-modal features can be used. A single modality is found to be insufficient to detect both internal and external distractions, mainly because of individual variability. In this work, we investigated multi-modal features: eye tracking and EEG data, to classify the internal and external distractions in an educational VR environment. We set up our educational VR environment and equipped it for multi-modal data collection. We implemented different machine learning (ML) methods, including k-nearest-neighbors (kNN), Random Forest (RF), one-dimensional convolutional neural network - long short-term memory (1 D-CNN-LSTM), and two-dimensional convolutional neural networks (2D-CNN) to classify participants' internal and external distraction states using the multi-modal features. We performed cross-subject, cross-session, and gender-based grouping tests to evaluate our models. We found that the RF classifier achieves the highest accuracy over 83% in the cross-subject test, around 68% to 78% in the cross-session test, and around 90% in the gender-based grouping test compared to other models. SHAP analysis of the extracted features illustrated greater contributions from the occipital and prefrontal regions of the brain, as well as gaze angle, gaze origin, and head rotation features from the eye tracking data.

Developmental Changes in How Head Orientation Structures Infants' Visual Attention.

Most studies of developing visual attention are conducted using screen-based tasks in which infants move their eyes to select where to look. However, real-world visual exploration entails active movements of both eyes and head to bring relevant areas in view. Thus, relatively little is known about how infants coordinate their eyes and heads to structure their visual experiences. Infants were tested every 3 months from 9 to 24 months while they played with their caregiver and three toys while sitting in a highchair at a table. Infants wore a head-mounted eye tracker that measured eye movement toward each of the visual targets (caregiver's face and toys) and how targets were oriented within the head-centered field of view (FOV). With age, infants increasingly aligned novel toys in the center of their head-centered FOV at the expense of their caregiver's face. Both faces and toys were better centered in view during longer looking events, suggesting that infants of all ages aligned their eyes and head to sustain attention. The bias in infants' head-centered FOV could not be accounted for by manual action: Held toys were more poorly centered compared with non-held toys. We discuss developmental factors-attentional, motoric, cognitive, and social-that may explain why infants increasingly adopted biased viewpoints with age.

Fixation patterns in pairs of facial expressions—preferences of self-critical individuals

So far, studies have revealed some differences in how long self-critical individuals fixate on specific facial expressions and difficulties in recognising these expressions. However, the research has also indicated a need to distinguish between the different forms of self-criticism (inadequate or hated self), the key underlying factor in psychopathology. Therefore, the aim of the current research was to explore fixation patterns for all seven primary emotions (happiness, sadness, fear, disgust, contempt, anger, and surprise) and the neutral face expression in relation to level of self-criticism by presenting random facial stimuli in the right or left visual field. Based on the previous studies, two groups were defined, and the pattern of fixations and eye movements were compared (high and low inadequate and hated self). The research sample consisted of 120 adult participants, 60 women and 60 men. We used the Forms of Self-Criticizing and Self-Reassuring Scale to measure self-criticism. As stimuli for the eye-tracking task, we used facial expressions from the Umeå University Database of Facial Expressions database. Eye movements were recorded using the Tobii X2 eye tracker. Results showed that in highly self-critical participants with inadequate self, time to first fixation and duration of first fixation was shorter. Respondents with higher inadequate self also exhibited a sustained pattern in fixations (total fixation duration; total fixation duration ratio and average fixation duration)—fixation time increased as self-criticism increased, indicating heightened attention to facial expressions. On the other hand, individuals with high hated self showed increased total fixation duration and fixation count for emotions presented in the right visual field but did not differ in initial fixation metrics in comparison with high inadequate self group. These results suggest that the two forms of self-criticism - inadequate self and hated self, may function as distinct mechanisms in relation to emotional processing, with implications for their role as potential transdiagnostic markers of psychopathology based on the fixation eye-tracking metrics.

Effects of teacher students’ study progress on their gaze behavior while solving of an economics knowledge test

Positive effects of study progress on the economic knowledge of bachelor students are evident and were often referred to as proof of the validity of tests in the context of a longitudinal analysis. However, differences between domain-specific (e.g., semester) or discipline-specific (e.g., attended courses) indicators of study progress on students’ solving the economics tasks are relevant for both diagnostic and instructional purposes, but have hardly been researched to date. In an eye tracking study, we therefore calculated the average fixation duration during 900 task-solving processes of 35 economics teacher students solving 25 single-choice economics tasks. A multi-level mediation analysis shows that both indicators (i.e., semester and attended courses) were positively correlated with economics knowledge. At the same time, the impact of semesters and courses attended on their test performance was partially mediated by average fixation duration on the attractor and distractors, respectively. This suggests that visual attention differs during the task-solving process depending on the domain- or discipline-specific indicator of study progress.

Are you what you emoji? how skin tone emojis and profile pictures shape attention and social inference processing

Emojis can express emotions and some aspects of the sender’s identity; however, only limited research has explored how the choice of skin tone in emojis influences the perceptions of the users. We examined the interaction between emoji skin tones and profile pictures in instant messaging, using self-reported and eye tracking measures. White participants viewed 14 screenshots of conversations (9 target and 5 fillers) where the sender used an emoji in a Darker or Lighter skin tone, or the default Yellow; alongside profile pictures displaying a Black or White individual, or a landscape as a neutral condition. Results showed that Black senders using Darker emojis were seen as warmer and closer to the receiver, but less competent, suggesting a dimensional compensation effect. Conversely, Black senders using Lighter emojis appeared more competent, but less warm. In the Neutral condition, Lighter emojis improved warmth and relationship quality, but reduced competence inferences, unlike Yellow and Darker emojis, suggesting a black sheep effect (in-group strictness). Yellow emojis were assumed to be sent by White individuals. Eye-tracking measures revealed an implicit bias towards White senders using Darker emojis, although such an impact was not observed for Black senders using Lighter emojis. Overall, findings indicate that skin tone emojis and profile pictures influence sender perception and challenge the neutrality of Yellow emojis.

Filtering on the Go: Effect of Filters on Gaze Pointing Accuracy During Physical Locomotion in Extended Reality.

Eye tracking filters have been shown to improve accuracy of gaze estimation and input for stationary settings. However, their effectiveness during physical movement remains underexplored. In this work, we compare common online filters in the context of physical locomotion in extended reality and propose alterations to improve them for on-the-go settings. We conducted a computational experiment where we simulate performance of the online filters using data on participants attending visual targets located in world-, path-, and two head-based reference frames while standing, walking, and jogging. Our results provide insights into the filters' effectiveness and factors that affect it, such as the amount of noise caused by locomotion and differences in compensatory eye movements, and demonstrate that filters with saccade detection prove most useful for on-the-go settings. We discuss the implications of our findings and conclude with guidance on gaze data filtering for interaction in extended reality.

Tasks Reflected in the Eyes: Egocentric Gaze-Aware Visual Task Type Recognition in Virtual Reality.

With eye tracking finding widespread utility in augmented reality and virtual reality headsets, eye gaze has the potential to recognize users' visual tasks and adaptively adjust virtual content displays, thereby enhancing the intelligence of these headsets. However, current studies on visual task recognition often focus on scene-specific tasks, like copying tasks for office environments, which lack applicability to new scenarios, e.g., museums. In this paper, we propose four scene-agnostic task types for facilitating task type recognition across a broader range of scenarios. We present a new dataset that includes eye and head movement data recorded from 20 participants while they engaged in four task types across 15 360-degree VR videos. Using this dataset, we propose an egocentric gaze-aware task type recognition method, TRCLP, which achieves promising results. Additionally, we illustrate the practical applications of task type recognition with three examples. Our work offers valuable insights for content developers in designing task-aware intelligent applications. Our dataset and source code are available at zhimin-wang.github.io/TaskTypeRecognition.html.

Voluntary Attention Assessing Tests in Children with Neurodevelopmental Disorders Using Eye Tracking

Background/Objectives: The development of techniques for assessing cognitive functions using eye tracking is particularly important for children with developmental disabilities. In this paper, we present pilot results from the validation of two methods for assessing voluntary attention based on eye tracking. Methods: The study involved 80 children aged 3 to 8 years with neurodevelopmental disorders. Children performed two eye-tracking tests in which they had to ‘catch’ a stimulus by looking at it. They also completed the Attention Sustained subtest of the Leiter-3 International Performance Scale. In the first test, the stimuli were presented at different locations on the screen in subtests with stimuli onset asynchrony of 2 s and 1 s. A translucent blue marker marked the position of the gaze on the screen. The number of trials in which the gaze marker approached the stimulus was determined. In the second test, the location of the stimuli on the screen was changed based on gaze fixation in the ROI area. The time taken to complete the task was evaluated. Results: The results of both eye-tracking tests showed significant correlations with scores on the Attention Sustained Leiter-3 subtest and significant test–retest reliability. Conclusions: The results indicate that the present eye-tracking tests can be used for assessing voluntary attention in children with some neurodevelopmental disorders, and further research is warranted to assess the feasibility of these tests for a broader range of developmental disorders. Our findings could have practical implications for the early intervention and ongoing monitoring of attention-related issues.

Implications of Retrograde Behaviours on Visual and Cycling Behaviour of Normal Cyclists

In China and other developing countries, some bicycle riders exhibit retrograde behaviour, which affects the riding safety of normal cyclists. The effect of retrograde behaviour on visual search and cycling behaviours of normal cyclists is investigated and quantified in this study. First, cyclists are instructed to wear an SMI iView ETG head-mounted mobile eye tracker and a mobile phone equipped with a Global Positioning System real-time location monitoring function to cycle on a road to obtain the times of fixation, saccade and blink, as well as the pupil diameter, gaze position and velocity in normal and retrograde conditions. Subsequently, the effect of retrograde behaviour on the attention of normal cyclists is analysed using three indexes: proportion of fixation time, coefficient of variation of pupil diameter and area of interest. Then, the effect of cycling behaviour is analysed using three indexes: the cycling trajectory, the velocity at three stages and the coefficient of variation of velocity. Finally, polynomial regression analysis is performed to analyse the visual and cycling behaviour impact indexes under the retrograde condition. The results show that retrograde behaviour significantly affects the vision and cycling behaviour of normal cyclists and that the two indexes are positively correlated.

Systematic review of cognitive impairment in drivers through mental workload using physiological measures of heart rate variability

The intricate interplay between driver cognitive dysfunction, mental workload (MWL), and heart rate variability (HRV) provides a captivating avenue for investigation within the domain of transportation safety studies. This article provides a systematic review and examines cognitive hindrance stemming from mental workload and heart rate variability. It scrutinizes the mental workload experienced by drivers by leveraging data gleaned from prior studies that employed heart rate monitoring systems and eye tracking technology, thereby illuminating the correlation between cognitive impairment, mental workload, and physiological indicators such as heart rate and ocular movements. The investigation is grounded in the premise that the mental workload of drivers can be assessed through physiological cues, such as heart rate and eye movements. The study discovered that HRV and infrared (IR) measurements played a crucial role in evaluating fatigue and workload for skilled drivers. However, the study overlooked potential factors contributing to cognitive impairment in drivers and could benefit from incorporating alternative indicators of cognitive workload for deeper insights. Furthermore, investigated driving simulators demonstrated that an eco-safe driving Human-Machine Interface (HMI) significantly promoted safe driving behaviors without imposing excessive mental and visual workload on drivers. Recommendations were made for future studies to consider additional indicators of cognitive workload, such as subjective assessments or task performance metrics, for a more comprehensive understanding.

Characterization of implicit and explicit mind-reading in children with autism based on eye movements

ObjectiveThis study aimed to investigate differences in mind-reading abilities between children with autism and typically developing children across various tasks.MethodsSixteen children with autism (aged 5-8 years) were compared to 16 typically developing children matched in language ability. The unexpected location task and unexpected content task were used to assess implicit and explicit mind-reading abilities using an eye tracker and illustrated storybooks.ResultsFor implicit mind, using differential looking scores shows a no significant difference between the scores of children with autism and typically developing children in the implicit tasks (P=0.399). However, the pupil size show some significant difference between two groups. Second, for the explicit, a significant difference between the scores of children with autism and typically developing children in the explicit tasks (P=0.006). Additionally, only a significant correlation between implicit and explicit mind-reading abilities in children with autism in the unexpected location task was found.ConclusionThe mechanism of implicit mind-reading still not very clear. Pupil-Linked arousal response can be consider as a further tool. Further research on implicit and explicit mind-reading abilities is warranted.

The timing of vision in basketball three-point shots

The aim of the present study was to explore the relationship between gaze behaviour, motor responses and the direction of visual attention when different levels of basketball players were engaged in a basketball three-point shot. Twelve near-experts and 12 amateur basketball players, wearing an eye tracker and an inertial sensor, performed 20 shots on a basketball field, receiving the ball from a teammate, who then acted as the opponent. The trial sequence was subdivided into catching, aiming and ball flight phases. The analysis demonstrated that near-experts exhibited longer fixation durations and saccades of lower amplitude and peak velocity than amateurs. The gaze behaviour showed that all players utilized fixations during the last part of the catching phase, during most of the aiming phase, and during the final part of the ball flight phase. The greatest number of saccades was exhibited between the aiming and the ball flight phases, when the ball was released by the players. Saccades were oriented toward the teammate during the catching phase. Instead, during the aiming and ball flight phases, saccade orientations were not polarized toward a specific visual cue. In conclusion, vision plays a critical role in every aspect of the three-point shot in basketball, from catching the ball, to aiming preparation, and shot execution. It is a key factor in decision-making, spatial awareness, and overall performance in team sports.