Eye-tracking Metrics Research Articles

The effect of seasonality and weather conditions on human perception of the urban–rural transitional landscape

Landscape perception research into the impact of seasonally changing landscape characteristics with the simultaneous influence of the weather are rare. Therefore, eye-tracking metrics were calculated (fixation and saccades) for the whole tested landscape, while its areas of interest (AOIs) were established based on clustering methods. Moreover, the gaze pattern was analysed using the Voronoi cells method. To identify significant differences in landscape perception according to various weather and seasonality, nonparametric tests were applied. The significant influence of weather/seasonality and their synergistic influence is noticed. The results indicate a rather complex influence of the types of weather in warmer and cooler seasons. Regardless of the weather type, seasonal changes cause greater visual span and shorter fixations in the warmer season. The fixations and saccades are shorter in the warmer season in two AOI’s during positive weather, but are longer in negative weather during the colder season in most AOI’s. The main reasons for the influence of weather and seasonality on the visual perception include seasonal changes in the landscape, resulting in the appearance of the landscape from more urban to natural and vice versa (phenological changes) as well as lighting changes (due to seasonality and type of weather).

Eye Tracking-Based Adaptive Displays: A Review of the Recent Literature

Adaptive displays have long been touted as a means of improving the usability of different types of interfaces. However, purely eye tracking-based adaptive displays have not yet lived up to the initial promise. In many cases, adaptive displays are tailored to users with special needs, developed to supplement virtual reality, or combine eye tracking with other physiological measures. This mapping review focuses instead on recent adaptive displays that rely solely on eye tracking input to understand a user’s needs while interacting with a regular computer display. We aimed to answer three main research questions related to 1) the application domains of such adaptive displays, 2) the eye tracking metrics that have been adopted to track attention allocation in real time, and 3) the adaptation triggering mechanisms. We provide a summary of the current state of eye tracking-based adaptive displays, identify gaps in the literature, and suggest topics for future work.

Nonlinear features of gaze behavior during joint attention in children with autism spectrum disorder.

Since children with autism spectrum disorder (ASD) might exhibit a variety of aberrant response to joint attention (RJA) behaviors, there is growing interest in identifying robust, reliable and valid eye-tracking metrics for determining differences in RJA behaviors between typically developing (TD) children and those with ASD. Previous eye-tracking studies have not been deeply investigated nonlinear features of gaze time-series during RJA. As a main motivation, this study aimed to extract three nonlinear features (i.e., complexity, long-range correlation, and local instability) of gaze time-series during RJA in children with ASD, which can be measured by fractal dimension (FD), Hurst exponent (H), and largest Lyapunov exponent (LLE), respectively. To illustrate our idea, this study adopted a publicly accessible database, including eye-tracking data collected during RJA from 19 children with ASD (7.74 ± 2.73) and 30 TD children (8.02 ± 2.89), and conducted a battery of nonparametric analysis of covariance (ANCOVA), where gender was used as covariable. Findings showed that gaze time-series during RJA in autistic children may generally have greater FD but lower H than that in TD controls. This implies that children with ASD possess more complex and unpredictable gaze behaviors during RJA than TD children. Furthermore, nonlinear metrics outperformed traditional eye-tracking metrics in obtaining higher identification performance with an accuracy of 82% and an AUC value of 0.81, distinguishing the differences between successful and failed RJA trails, and predicting the severity of ASD symptoms. Findings might bring some new insights into the understanding of the impairments in RJA behaviors for children with ASD.

Comparing driver reaction and mental workload of visual and auditory take-over request from perspective of driver characteristics and eye-tracking metrics

The objective of this study was to compare the driver’s reaction and mental workload of different take-over requests (TOR) modalities concerning driver characteristics in semi-autonomous driving when the driver is engaged in different non-driving related tasks. A driving simulator was developed for two TOR modalities (visual and auditory). Thirty-three individuals participated in the driving simulation experiment. NASA Task Load Index, driver characteristics (driving style questionnaire and work-load sensitive questionnaire), and eye-tracking metrics were collected. Through the structural equation model, we found that driving style affects driver’s mental work-load and reaction sequence in a visual TOR alert situation, while in auditory TOR alert situation, a driver characteristics have no significance on mental workload and reaction sequence. Strong correlation between mental workload and reaction sequence was only found in the auditory TOR alert situation. These results can be used to develop an adaptive multi-modal interface that take driver characteristics into account.

Correlating Eye-Tracking Fixation Metrics and Neuropsychological Assessment after Ischemic Stroke.

Background and Objectives: Stroke survivors commonly experience cognitive deficits, which significantly impact their quality of life. Integrating modern technologies like eye tracking into cognitive assessments can provide objective and non-intrusive measurements. Materials and Methods: This study aimed to evaluate the cognitive and visual processing capabilities of stroke patients using eye-tracking metrics and psychological evaluations. A cohort of 84 ischemic stroke patients from the N-PEP-12 clinical study was selected for secondary analysis, based on the availability of eye-tracking data collected during a visual search task using an adapted Trail Making Test. Standardized cognitive assessments, including the Montreal Cognitive Assessment (MoCA) and digit span tasks, were also conducted. Results: Correlation analyses revealed some notable relationships between eye-tracking metrics and cognitive measures, such as a positive correlation between Symbol Search performance and the number of fixations. Anxiety levels were found to be positively correlated with first fixation duration, while longer first fixation durations were associated with poorer cognitive performance. However, most correlations were not statistically significant. Nonparametric ANOVA showed no significant differences in fixation metrics across the visits. Conclusions: These findings suggest a complex relationship between cognitive status, gaze fixation behavior, and psychological well-being in stroke patients. Further research with larger sample sizes and analysis of saccadic eye movements is needed to better understand these relationships and inform effective interventions for stroke rehabilitation.

From reading style to cognitive style and its possible application: an eye-tracking and CFT approach

Reading strategies and cognitive styles have been the objective of many researchers. However, the relation between these two concepts remains unclear. This paper is focusing on three goals. Firstly, we verify the reliability of the eye-tracking indicators of risky and conservative reading style. Secondly, we aim to explore an additional eye-tracking pattern that may reflect the reading style on the global level. Thirdly, we explore the relationship between reading style and the holistic/analytic cognitive style. The study is based on a combination of Compound Figure Test (CFT) as a main tool for analyzing cognitive style and eye-tracking study consisting of several text stimuli related to verify reading style patterns. Results showed stability across the reading tasks, which validates for the usefulness and reliability of original Rayner’s as well as the new additional eye-tracking metrics. The stability of the eye-tracking metrics allows us to treat them as a behavioral profile in information processing that may be viewed as a stable personality trait known as reading style. However, the eye-tracking results and the CFT global preference score did not show a detectably close relation between cognitive style and reading style. In conclusion, we also discuss the possibility of applying these eye-tracking patterns to foreign language material design.

Shifty Eyes: The Impact of Intolerance of Uncertainty on Gaze Behaviour During Threat Conditioning

Previous research has demonstrated that individuals with high levels of Intolerance of Uncertainty (IU) have difficulty updating threat associations to safety associations. Notably, prior research has focused on measuring IU-related differences in threat and safety learning using arousal-based measures such as skin conductance response. Here we assessed whether IU-related differences in threat and safety learning could be captured using eye-tracking metrics linked with gaze behaviours such as dwelling and scanning. Participants (N = 144) completed self-report questionnaires assessing levels of IU and trait anxiety. Eye movements were then recorded during each conditioning phase: acquisition, extinction learning, and extinction retention. Fixation count and fixation duration served as indices of conditioned responding. Patterns of threat and safety learning typically reported for physiology and self-report were observed for the fixation count and fixation duration metrics during acquisition and to some extent in extinction learning, but not for extinction retention. There was little evidence for specific associations between IU and disrupted safety learning (e.g., greater differential responses to the threat vs. safe cues during extinction learning and retention). While there was tentative evidence that IU was associated with shorter fixation durations (e.g., scanning) to threat vs. safe cues during extinction retention, this effect did not remain after controlling for trait anxiety. IU and trait anxiety similarly predicted greater fixation count and shorter fixation durations overall during extinction learning, and greater fixation count overall during extinction retention. IU further predicted shorter fixation durations overall during extinction retention. However, the only IU-based effect that remained significant after controlling for trait anxiety was that of fixation duration overall during threat extinction learning. Our results inform models of anxiety, particularly in relation to how individual differences modulate gaze behaviour during threat conditioning.

How to visualize electricity consumption anomalies: The impact of chart types on triggered emotions and eye movements

Home Energy Management Systems (HEMS) show anomalies and unusual patterns of the electricity consumption of households, usually in the form of charts. Charts that show anomalies are very difficult to design in a way that is both comprehensible and visually appealing to users. However, visually appealing charts direct the users’ gaze to the central chart elements and thus trigger positive emotions, which in turn increase the intention to use HEMS. Therefore, this study focuses on the emotions and eye movements that different chart types showing anomalous electricity consumption trigger. An experimental eye-tracking and facial expression study was carried out with 50 participants that were randomly assigned to one of three commonly used chart types (bar, line or rose chart). The participants had to complete three search tasks during which the eye movements and the facial expressions were observed. The results show that different emotions are triggered depending on the chart type. Participants showed the highest number of sad and contempt facial expressions while viewing bar charts. Line charts triggered the most positive and, overall, the least negative facial expressions, followed by the rose charts. Bar charts triggered the most negative emotions among all three chart types. Although most eye-tracking metrics in this study differed by chart type, most results did not show significant differences. However, the later participants saw the area in demand in the rose charts, the sadder facial expressions occurred. HEMS providers can use these findings to design emotionally appealing charts for potential users, which in turn can increase their motivation to use these systems.

Predicting Decision-Making in Virtual Environments: An Eye Movement Analysis with Household Products

Understanding consumer behavior is crucial for increasing the likelihood of product success. Virtual Reality head-mounted displays incorporating physiological techniques such as eye-tracking offer novel opportunities to study user behavior in decision-making tasks. These methods reveal unconscious or undisclosed consumer responses. Yet, research into gaze patterns during virtual product evaluations remains scarce. In this context, an experiment was conducted to investigate users’ gaze behavior when evaluating their preferences for 64 virtual prototypes of a bedside table. Here, 24 participants evaluated and selected their preferred design through eight repeated tasks of an 8-AFC, with individual evaluations conducted for each design to ensure the reliability of the findings. Several eye-tracking metrics were computed (i.e., gaze time, visits, and time to first gaze), statistical tests were applied, and a Long Short-Term Memory model was created to recognize decisions based on attentional patterns. Our results revealed that the Gaze Cascade Model was replicated in virtual environments and that a correlation between product liking and eye-tracking metrics exists. We recognize subjects’ decisions with a 90% accuracy, based on their eye patterns during the three seconds before their decision. The results suggest that eye-tracking can be an effective tool for decision-making prediction during product assessment in virtual environments.

Eye-Tracking Study on the Gender Effect Towards Cognitive Processes During Multimedia Learning

Multimedia learning is defined as the process of forming a knowledge mental model from words and pictures. It is important to measure cognitive process during multimedia learning. Differences in learners’ capabilities can be investigated through cognitive processes to improve the learning process. However, conventional methods such as interviews or behavioural assessment do not provide an objective measurement of cognitive processes during multimedia learning. Some advance methods to measure cognitive processes takes into account learner’s eye movement during learning process. In such a case, eye-tracking can be used as an alternative method to measure cognitive processes because eye movement has become a major part of human cognitive function. Another issue is related to the learners with different gender, which might have different styles of interaction with the source of information. Unfortunately, the effect of gender disparities in multimedia learning has not been widely studied. To address this research gap, this study examines the effect of gender differences based on eye-tracking metrics during multimedia learning. Based on the experimental results, `time until first fixation` on the text-type area of interest (AOI), `number of fixations` on the image type AOI, and `transition` from text-type AOI to image-type as well as `transition` between Image AOIs provided notable distinctions for each gender group (p < 0.05). It was found that male learners preferred to access information from images. In contrast, female learners tended to do a thorough inspection on textual and pictorial information during multimedia learning. This study can be used as an alternative method for collecting cognitive process indicators in multimedia learning.

Decreased emotion recognition and reduced focus on facial hallmarks in behavioral variant frontotemporal dementia compared to primary psychiatric disorders and controls.

Early diagnosis of behavioral variant frontotemporal dementia (bvFTD) is challenging due to symptomatic overlap with primary psychiatric disorders (PPD). As emotion recognition deficits are early and key features of bvFTD, the aim was to explore processes driving social cognition deficits that may aid in the differentiation between bvFTD and PPD. The total sample (N = 51) included 18 patients with bvFTD, 11 patients with PPD (mood, autism spectrum and psychotic disorders) and 22 controls from the Alzheimer Center Amsterdam of the Amsterdam UMC. Emotion recognition was assessed with the Ekman 60 Faces test, during which eye tracking metrics were collected in the first 5 s a face was presented. Group differences in dwell time on the total image as well as the circumscribed eyes area and mouth area were analysed using ANOVA, with post hoc comparisons. Patients with bvFTD scored lowest, patients with PPD scored intermediate and controls scored highest on emotion recognition. During facial processing, patients with bvFTD spent less dwell time on the total image than controls (mean difference 11.3%, F(2, 48) = 6.095, p = 0.004; bvFTD-controls p = 0.001, 95% confidence interval [CI] -892.64, -239.70). Dwell time on the eyes area did not differ between diagnostic groups, whilst patients with bvFTD spent less dwell time on the mouth area than PPD patients (mean difference 10.7%; F(2, 48) = 3.423, p = 0.041; bvFTD-PPD p = 0.022, 95% CI -986.38, -79.47) and controls (mean difference 7.8%; bvFTD-controls p = 0.043, 95% CI -765.91, -12.76). In bvFTD, decreased emotion recognition may be related to reduced focus on facial hallmarks. These findings suggest a valuable role for biometrics in social cognition assessment and the differentiation between bvFTD and PPD.

Bright-light distractions and visual performance.

Visual distractions pose a significant risk to transportation safety, with laser attacks against aircraft pilots being a common example. This study used a research-grade High Dynamic Range (HDR) display to produce bright-light distractions for 12 volunteer participants performing a combined visual task across central and peripheral visual fields. The visual scene had an average luminance of 10 cd∙m-2 with targets of approximately 0.5° angular size, while the distractions had a maximum luminance of 9,000 cd∙m-2 and were 3.6° in size. The dependent variables were the mean fixation duration during task execution (representative of information processing time), and the critical stimulus duration required to support a target level of performance (representative of task efficiency). The experiment found a statistically significant increase in mean fixation duration, rising from 192 ms without distractions to 205 ms with bright-light distractions (p = 0.023). This indicates a decrease in visibility of the low contrast targets or an increase in cognitive workload that required greater processing time for each fixation in the presence of the bright-light distractions. Mean critical stimulus duration was not significantly affected by the distraction conditions used in this study. Future experiments are suggested to replicate driving and/or piloting tasks and employ bright-light distractions based on real-world data, and we advocate the use of eye-tracking metrics as sensitive measures of changes in performance.

Eye Gaze Patterns during Reasoning Provide Insights Regarding Individual Differences in Underlying Cognitive Abilities.

Sequences of eye movements during performance of a reasoning task has provided insights into the strategies individuals use to solve that specific task; however, prior studies have not examined whether eye gaze metrics reflect cognitive abilities in a way that transcends a specific task. Thus, our study aimed to explore the relationship between eye movement sequences and other behavioral measures. Here, we present two studies that related different eye gaze metrics in a matrix reasoning task with performance on a different test of fluid reasoning and tests of planning, working memory, and cognitive flexibility. Additionally, we related gaze metrics to self-reported executive functioning in daily life, as measured by BRIEF-A. To perform this, we classified the participants' eye gaze in each item of the matrices test using an algorithm and then used LASSO regression models with the cognitive abilities as the dependent variable to select eye-tracking metrics to predict it. Overall, specific and distinct eye gaze metrics predicted 57% variance in the fluid reasoning scores; 17% variance in the planning scores; and 18% variance in the working memory scores. Taken together, these results support the hypothesis that the selected eye-tracking metrics reflect cognitive abilities that transcend specific tasks.

Utilizing Eye Tracking to Assess Medical Student Non-Technical Performance During Scenario-Based Simulation: Results of a Pilot Study.

Non-technical skills (NTS) are essential for safe surgical patient management. However, assessing NTS involves observer-based ratings, which can introduce bias. Eye tracking (ET) has been proposed as an effective method to capture NTS. The purpose of the current study was to determine if ET metrics are associated with NTS performance. Participants wore a mobile ET system and participated in two patient care simulations, where they managed a deteriorating patient. The scenarios featured several challenges to leadership, which were evaluated using a 4-point Likert scale. NTS were evaluated by trained raters using the Non-Technical Skills for Surgeons (NOTSS) scale. ET metrics included percentage of fixations and visits on areas of interest. Ten medical students participated. Average visit duration on the patient was negatively correlated with participants' communication and leadership. Average visit duration on the patient's intravenous access was negatively correlated with participants' decision making and situation awareness. Our preliminary data suggests that visual attention on the patient was negatively associated with NTS and may indicate poor comprehension of the patient's status due to heightened cognitive load. In future work, researchers and educators should consider using ET to objectively evaluate and provide feedback on their NTS.

The Effects of Type and Form of Collaborative Robots in Manufacturing on Trustworthiness, Risk Perceived, and Acceptance

As one of the latest applications in the field of artificial intelligence, collaborative robots (cobots) are playing an increasingly important role in manufacturing. This study is aimed to ascertain the effects of the type and form of a collaborative robot in manufacturing on trustworthiness, risk perceived, and acceptance. A 2 (single-arm cobot/dual-arm cobot) * 2 (cobot with a screen/cobot without a screen) full factorial within-subject experiment was conducted by using eye-tracking metrics and subjective questionnaires. A total of 40 participants were recruited and all stimuli were played randomly. Results suggest both features are essential attributes with interactive effects in the process of viewing tasks. For single-arm cobots, cobots without a screen showed higher trustworthiness than those with a screen. Dual-arm cobots with a screen showed higher perceived risk than those without a screen. Furthermore, compared to the cobots without a screen, cobots with a screen evidenced more fixation counts and longer fixation duration, which means more attention resources and greater cognitive effort were required. The same results were also found in dual-arm cobots. This study contributes to the extant literature on cobot design and training by emphasizing the effect of cobot form and type in particular.

The Identification of Individualized Eye Tracking Metrics in VR Using Data Driven Iterative- Adaptive Algorithm

Eye tracking metrics provide information about cognitive function and basic oculomotor characteristics. There have been many studies analyzing eye tracking signals using different algorithms. However, these algorithms generally are based on the initial setting parameter. This might cause the subjective interpretation of eye tracking analysis. The main aim of this study was to develop a data-driven algorithm to detect fixations and saccades without any subjective settings. Three subjects were included in this study. Eye tracking signal was acquired with the VIVE Pro Eye in virtual reality (VR) environment while subjects were reading a paragraph. The algorithms based on the calculation of threshold were employed to calculate eye metrics including total fixation duration, total fixation number, total saccades number and average pupil diameter. The proposed algorithm, which is based on calculating the initial threshold, based on mean, and standard deviation of eye tracking signal within experiment duration, gave the same results obtained adaptive filtering reported in literature (average fixation duration for three subjects= 11515 ms ± 6951.2, average fixation count for three subjects= 17.33 ± 4.16). On the other hand, our proposed algorithm didn’t use any certain objective parameter as like adaptive filtering. As a conclusion, VIVE Pro Eye may be utilized as an eye movement assessment device, and, the suggested approach might be utilized to analyze objective eye tracking metrics.

Wine label design proposals: an eye-tracking study to analyze consumers’ visual attention and preferences

PurposeThe main purpose of this study is to analyze how consumers’ visual attention to wine label design correlates with their preferences. Accordingly, this study uses quantitative eye-tracking metrics to understand which design proposal has greater visual salience. A more specific objective was to assess which design proposal was preferred to be marketed.Design/methodology/approachThe experiment involved evaluating of three different labeling proposals of an Italian winery. Infrared eye-tracking was used to measure implicit eye movements on the three bottles displayed, simultaneously, on a computer screen. A generalized linear model was used to test how consumers' visual attention to wine label design correlated with their preferences.FindingsThe design proposals were evaluated significantly differently, with one set being preferred. In general, a strong positive relationship was found between pausing to peruse a specific design proposal and making an explicit choice of the same bottle.Research limitations/implicationsThe main limitation of the experiment concerns the sample interviewed. As the sample is homogeneous, the results may not be generalizable to other segments. Furthermore, the addition of electroencephalographic devices that monitor brain activity could provide crucial information for understanding consumer behavior during the purchase decision-making process.Practical implicationsEye-tracking methods could be useful for designers and wine producers during the evaluation process of design projects.Originality/valueThe use of eye-tracking for evaluating design proposals before placing a product on the market is relatively novel. This method provides objective, quantitative and predictive information on consumer preferences contributing guidelines to designers and marketers during the product conception phase.

Detailing experienced nurse decision making during acute patient care simulations

IntroductionNurse decision making (DM) is critical for patient safety. Eye-tracking methods can effectively assess nurse DM. The purpose of this pilot study was to use eye-tracking methods to assess nurse DM during a clinical simulation. Materials and methodsExperienced nurses managed a simulated patient manikin who suffered from a stroke mid-simulation. We assessed nurses’ gaze patterns prior to and after the stroke. DM in general was assessed by nursing faculty using a clinical judgement rubric, and dichotomously based on recognition of the stroke or not. ResultsData from eight experienced nurses was examined. For the nurses who recognized the stroke, visual attention was focused on the vital sign monitor and patient's head, which suggest those locations were consistently examined for correct decision-makers. ConclusionsDwell time on general AOIs was associated with poorer DM, which may reflect poorer pattern recognition. Eye-tracking metrics may be effective to objectively assess nurse DM.

Impact of swiping direction on the interaction performance of elderly-oriented smart home interface: EEG and eye-tracking evidence.

Smart home technology is increasingly popular, yet not all seniors are receptive and comfortable with it. This situation recognizes that the usability of smart home interfaces is particularly important. Most studies on interface swiping direction demonstrate the advantages of horizontal over vertical swiping, but the findings lack age-based as well as gender-specific judgments. In this paper, we use cognitive neural techniques of EEG and eye-tracking, combined with a subjective preference questionnaire, to analyze the preference of older persons for the swiping direction of smart home interfaces in a multimodal manner. The EEG data showed that swiping direction had a significant effect on potential values (p = 0.001). Also, the mean power in the δ and the θ band was enhanced during vertical swiping. Gender had no significant effect on potential values (p = 0.085), but the cognitive task was more EEG stimulating for females. The eye-tracking metrics data showed a significant effect of swiping direction on fixation duration (p = 0.047) and a non-significant effect on pupil diameter (p = 0.576). These results were consistent with the results of the subjective preference questionnaire, both demonstrating a preference for vertical swiping among participants. This paper uses three research tools simultaneously, combining objective perceptions as well as subjective preferences, to make the findings more comprehensive and reliable. Gender differences were also taken into account and differentiated in the data processing. The findings of this paper are different from most previous studies and better reflect the preference of elderly people for swiping directions, which can provide a reference for the future elderly-friendly smart home interface design.

Examining the validity of eye tracking during the computerized Wisconsin card sorting test in a sample of stroke patients and healthy controls

ABSTRACT Introduction Each year, approximately 50,000 Canadians, one million Americans, and millions of people worldwide are hospitalized for stroke. Cognitive impairment is common after experiencing a stroke and is known to affect functioning on daily tasks. While neuropsychological assessments are often employed to assess cognitive abilities and make inferences about functional capabilities, there is growing interest in integrating contemporary technologies to augment assessment. Eye tracking allows previously overlooked information, such as overt visual attention based on fixations and saccades, to be quantified to help elucidate how responses are made during testing. Method The current study investigated the validity of eye tracking during completion of the computerized Wisconsin Card Sorting Test (cWCST), a common test of higher level cognition, in a sample of inpatients recovering from stroke (n= 41) and a control group of healthy individuals (n = 46). Results Results provided supporting evidence for the construction, criterion, and ecological validity of eye tracking on the cWCST with inpatients recovering from a stroke. Specifically, eye tracking metrics differentiated between inpatients and controls; fixations on cWCST areas of interest differed between type of response (conceptual versus non-conceptual); and average time per fixation predicted functional status early after a stroke as well as recovery during inpatient rehabilitation, above-and-beyond cWCST scores. Time spent on testing negated the effects of fixation and saccade counts for predicting cWCST performance, due to the substantial overlap in variance. Conclusion Current findings of this preliminary study provided support for the validity of eye tracking, integrated with the cWCST, for inpatients recovering from a stroke. Implications and areas for future research are discussed.