Enhancing ensemble classifiers utilizing gaze tracking data for autism spectrum disorder diagnosis.

PROBLEM: Diagnosing Autism Spectrum Disorder (ASD) remains a significant challenge, especially in regions where access to specialists is limited. Computer-based approaches offer a promising solution to make diagnosis more accessible. Eye tracking has emerged as a valuable technique in aiding the diagnosis of ASD. Typically, individuals' gaze patterns are monitored while they view videos designed according to established paradigms. In a previous study, we developed a method to classify individuals as having ASD or Typical Development (TD) by processing eye-tracking data using Random Forest ensembles, with a focus on a paradigm known as joint attention. AIM: This article aims to enhance our previous work by evaluating alternative algorithms and ensemble strategies, with a particular emphasis on the role of anticipation features in diagnosis. METHODS: Utilizing stimuli based on joint attention and the concept of "floating regions of interest" from our earlier research, we identified features that indicate gaze anticipation or delay. We then tested seven class balancing strategies, applied seven dimensionality reduction algorithms, and combined them with five different classifier induction algorithms. Finally, we employed the stacking technique to construct an ensemble model. RESULTS: Our findings showed a significant improvement, achieving an F1-score of 95.5%, compared to the 82% F1-score from our previous work, through the use of a heterogeneous stacking meta-classifier composed of diverse induction algorithms. CONCLUSION: While there remains an opportunity to explore new algorithms and features, the approach proposed in this article has the potential to be applied in clinical practice, contributing to increased accessibility to ASD diagnosis.

Sharing Our World: Impact of Group Motor Skill Learning on Joint Attention in Children with Autism Spectrum Disorder.

Impaired joint attention is a common feature of autism spectrum disorder (ASD), affecting social interaction and communication. We explored if group basketball learning could enhance joint attention in autistic children, and how this relates to brain changes, particularly white matter development integrity. Forty-nine autistic children, aged 4-12 years, were recruited from special education centers. The experimental group underwent a 12-week basketball motor skill learning, while the control group received standard care. Eye-tracking and brain scans were conducted. The 12-week basketball motor skill learning improved joint attention in the experimental group, evidenced by better eye tracking metrics and enhanced white matter integrity. Moreover, reduced time to first fixation correlated positively with decreased mean diffusivity of the left superior corona radiata and left superior fronto-occipital fasciculus in the experimental group. Basketball-based motor skill intervention effectively improved joint attention in autistic children. Improved white matter fiber integrity related to sensory perception, spatial and early attention function may underlie this effect. These findings highlight the potential of group motor skill learning within clinical rehabilitation for treating ASD.

Automated visual acuity estimation by optokinetic nystagmus using a stepped sweep stimulus.

PURPOSE: To describe an automatic system for objective measurement of visual acuity (VA) using optokinetic nystagmus (OKN). This pilot study tested the system's sensitivity and specificity for detecting reduced VA in healthy adults by comparing VA-OKN to VA with an Early Treatment of Diabetic Retinopathy Study (ETDRS) chart (VA-ETDRS). METHODS: Adult participants (age 30 ± 12 years) with either reduced VA (n = 11, VA-ETDRS > 0.20 logMAR) or normal VA (n = 12, VA-ETDRS ≤ 0.20 logMAR) completed monocular VA-OKN measurements in each eye. The VA-OKN stimulus was an array of drifting (5°/s) vanishing discs presented in descending/ascending size order (0.00-1.00 logMAR in 0.10 steps). The stimulus was stepped every 2 s, and 10 sweeps were shown per eye (five ascending and five descending). Eye-tracking data determined when OKN activity ceased (descending sweep) or began (ascending sweep), which was used to determine VA-OKN for each sweep. The estimates were averaged across sweeps to produce an automated VA-OKN. The automated sweeps were then provided in randomised order to a reviewer blinded to the VA-ETDRS findings who determined a final VA-OKN for an eye. RESULTS: A single randomly selected eye from each observer was used for analysis. The sensitivity and specificity of VA-OKN using the same 0.20 logMAR threshold as VA-ETDRS was 100%. Comparisons between the VA-OKN and VA-ETDRS measures were made for participants in the reduced VA group. There was no significant difference between VA-OKN and VA-ETDRS (p = 0.55) and the two measures produced comparable values (r2 = 0.84, 95% limits of agreement = 0.19 logMAR, intra-class correlation coefficient = 0.90 [95% CI:0.68-0.97]). CONCLUSIONS: Visual acuity using optokinetic nystagmus correctly identified a VA deficit in adults and for those with a VA deficit, VA-OKN was strongly correlated with the gold-standard clinical measure of VA. OKN is a promising method which has the potential for use in cognitively impaired adults and pre-verbal children.

Syntactic flexibility and lexical encoding in aging sentence production: an eye tracking study.

Purpose: Successful sentence production requires lexical encoding and ordering them into a correct syntactic structure. It remains unclear how different processes involved in sentence production are affected by healthy aging. We investigated (a) if and how aging affects lexical encoding and syntactic formulation during sentence production, using auditory lexical priming and eye tracking-while-speaking paradigms and (b) if and how verbal working memory contributes to age-related changes in sentence production. Methods: Twenty older and 20 younger adults described transitive and dative action pictures following auditory lexical primes, by which the relative ease of encoding the agent or theme nouns (for transitive pictures) and the theme and goal nouns (for dative pictures) was manipulated. The effects of lexical priming on off-line syntactic production and real-time eye fixations to the primed character were measured. Results: In offline production, older adults showed comparable priming effects to younger adults, using the syntactic structure that allows earlier mention of the primed lexical item in both transitive and dative sentences. However, older adults showed longer lexical priming effects on eye fixations to the primed character during the early stages of sentence planning. Preliminary analysis indicated that reduced verbal working memory may in part account for longer lexical encoding, particularly for older adults. Conclusion: These findings indicate that syntactic flexibility for formulating different grammatical structures remains largely robust with aging. However, lexical encoding processes are more susceptible to age-related changes, possibly due to changes in verbal working memory.

Multimodal insights into granger causality connectivity: Integrating physiological signals and gated eye-tracking data for emotion recognition using convolutional neural network.

This study introduces a groundbreaking method to enhance the accuracy and reliability of emotion recognition systems by combining electrocardiogram (ECG) with electroencephalogram (EEG) data, using an eye-tracking gated strategy. Initially, we propose a technique to filter out irrelevant portions of emotional data by employing pupil diameter metrics from eye-tracking data. Subsequently, we introduce an innovative approach for estimating effective connectivity to capture the dynamic interaction between the brain and the heart during emotional states of happiness and sadness. Granger causality (GC) is estimated and utilized to optimize input for a highly effective pre-trained convolutional neural network (CNN), specifically ResNet-18. To assess this methodology, we employed EEG and ECG data from the publicly available MAHNOB-HCI database, using a 5-fold cross-validation approach. Our method achieved an impressive average accuracy and area under the curve (AUC) of 91.00 % and 0.97, respectively, for GC-EEG-ECG images processed with ResNet-18. Comparative analysis with state-of-the-art studies clearly shows that augmenting ECG with EEG and refining data with an eye-tracking strategy significantly enhances emotion recognition performance across various emotions.

Harnessing technology to measure individual differences in spatial thinking in early childhood from a relational developmental systems perspective.

According to the Relational Developmental Systems perspective, the development of individual differences in spatial thinking (e.g., mental rotation, spatial reorientation, and spatial language) are attributed to various psychological (e.g., children's cognitive strategies), biological (e.g., structure and function of hippocampus), and cultural systems (e.g., caregiver spatial language input). Yet, measuring the development of individual differences in spatial thinking in young children, as well as the psychological, biological, and cultural systems that influence the development of these abilities, presents unique challenges. The current paper outlines ways to harness available technology including eye-tracking, eye-blink conditioning, MRI, Zoom, and LENA technology, to study the development of individual differences in young children's spatial thinking. The technologies discussed offer ways to examine children's spatial thinking development from different levels of analyses (i.e., psychological, biological, cultural), thereby allowing us to advance the study of developmental theory. We conclude with a discussion of the use of artificial intelligence.

Gaze behavior reveals automaticity and attention allocation during music teaching vs. observing.

In a unique case-study approach in which I served as both the research participant and the experimenter, I wore eye-tracking glasses while teaching a brief music lesson to two university students learning trumpet, then approximately two weeks later, I watched a video of the lesson and tracked my gaze again. To investigate unconscious perceptual processes engaged during music teaching, I compared my attention allocation while teaching to my attention allocation during selfobservation. My gaze behavior while teaching revealed a high level of automaticity regarding lesson sequencing and allocation of attention. Strategic moment-to-moment shifts in attention between the two students occurred entirely below my conscious awareness, yet post hoc analyses revealed precisely timed changes that were related to momentary goals. While watching the video, absent the demands of behavioral interaction and momentary decision-making, I directed more sustained attention to both students than I had while teaching. These results reveal important features of "teacher thinking" that are not directly observable or typically construed as conscious behavior. That this component of teaching practice does not involve volitional control suggests that teachers' descriptions of their thinking may not reveal to novices important elements of pedagogical expertise.

Accounting for Visual Field Abnormalities when Using Eye-tracking to Diagnose Reading Problems in Neurological Degeneration.

State-of-the-art eye trackers provide valuable information for diagnosing reading problems by measuring and interpreting people's gaze paths as they read through text. Abnormal conditions such as visual field defects, however, can seriously confound most of today's existing methods for interpreting reading gaze patterns. Our objective was to research how visual field defects impact reading gaze path patterns, so the effects of such neurological pathologies can be explicitly incorporated into more comprehensive reading diagnosis methodologies. A cross-sectional, non-randomized, pilot clinical study including 45 patients with various neurologic disorders and 30 normal controls was designed. Participants underwent ophthalmologic/neuropsychologic and eye-tracker examinations using two reading tests of words and numbers. The results showed that the use of the eye tracker showed that patients with brain damage and an altered visual field require more time to complete a reading-text test by fixating a greater number of times (p < 0.001); with longer fixations (p = 0.03); and a greater number of saccades in these patients (p = 0.04). Our study showed objective differences in eye movement characteristics in patients with neurological diseases and an altered visual field who complained of reading difficulties. These findings should be considered as a bias factor and deserve further investigation.

Age-related changes in connected speech production: evidence from eye-tracking in the culturally adapted picture description task.

Purpose: Age-related changes in connected speech production remain a subject of debate, yielding inconsistent findings across various tasks and measures. This study aimed to investigate the effects of aging on picture description tasks using two types of pictures: a standardized picture (the Beach picture) and a culturally and linguistically modified picture tailored for Korean speakers (the Han River picture). Method: Twenty-four young adults and 22 older adults participated in two picture description tasks while their eye movements were recorded. Word-level linguistic variables were used to assess informativeness (Correct Information Units per minute) and productivity (noun and verb counts per utterance) of connected speech production. Eye-movement measures were employed to evaluate real-time cognitive processing associated with planning connected speech (pre-speech fixation counts and durations; eye fixations before the speech onset of each utterance). Results and conclusions: The findings revealed age-related declines in linguistic measures, with older adults exhibiting decreased CIUs per minute and smaller counts of nouns and verbs per utterance. Age-related changes in eye movement measures were evident in that older adults displayed longer pre-speech fixation durations. Unlike younger adults, older adults exhibited higher pre-speech fixation counts on the Han River picture compared to the Beach picture, suggesting cognitive challenges in performing the task that requires producing more words and detailed descriptions. These results suggest that aging is associated with reduced informativeness and productivity of connected speech, as well as a decline in cognitive processing efficiency.

Spatiotemporal Eye Movement Dynamics Reveal Altered Face Prioritization in Early Visual Processing Among Autistic Children.

BACKGROUND: Reduced social attention - looking at faces - is one of the most common manifestations of social difficulty in autism central to social development. Although reduced social attention is well-characterized in autism, qualitative differences in how social attention unfolds across time remains unknown. METHODS: We used a computational modeling (i.e., hidden Markov modeling) approach to assess and compare the spatiotemporal dynamics of social attention in a large, well-characterized sample of autistic (n = 280) and neurotypical (n = 120) children (ages 6-11) that completed three social eye-tracking assays across three longitudinal time points (Baseline, 6 weeks, 24 weeks). RESULTS: Our analysis supported the existence of two common eye movement patterns that emerged across three ET assays. A focused pattern was characterized by small face regions of interest, which had high probability of capturing fixations early in visual processing. In contrast, an exploratory pattern was characterized by larger face regions of interest, with lower initial probability of fixation, and more non-social regions of interest. In the context of social perception, autistic children showed significantly more exploratory eye movement patterns than neurotypical children across all social perception assays and all three longitudinal time points. Eye movement patterns were associated with clinical features of autism, including adaptive function, face recognition, and autism symptom severity. CONCLUSIONS: Decreased likelihood of precisely looking to faces early in social visual processing may be an important feature of autism that was associated with autism-related symptomology and may reflect less visual sensitivity to face information.

Attention-language interface in Multilingual Assessment instrument for Narratives.

The current study employed the Multilingual Assessment Instrument for Narratives (MAIN) to test comprehension of narrative macrostructure in Russian in a visual world eye-tracking paradigm. The four MAIN visual narratives are structurally similar and question referents' goals and internal states (IS). Previous research revealed that children's MAIN comprehension differed among the four narratives in German, Swedish, Russian, and Turkish, but it is not clear why. We tested whether the difference in comprehension was (a) present, (b) caused by complicated inferences in understanding IS compared with goals, and (c) ameliorated by orienting visual attention to the referents whose IS was critical for accurate comprehension. Our findings confirmed (a) and (b) but found no effect of attentional cues on accuracy for (c). The multidimensional theory of narrative organization of children's knowledge of macrostructure needs to consider the type of inferences necessary for IS that are influenced by subjective interpretation and reasoning.

Clinical Utility of Ocular Assessments in Sport-Related Concussion: A Scoping Review.

Background/objectives: Ocular tools and technologies may be used in the diagnosis of sport-related concussions (SRCs), but their clinical utility can vary. The following study aimed to review the literature pertaining to the reliability and diagnostic accuracy of such assessments. Methods: The preferred reporting items for systematic reviews and meta-analysis (PRISMA) extension for scoping reviews was adhered to. Reference standard reliability (RSR ≥ 0.75) and diagnostic accuracy (RSDA ≥ 0.80) were implemented to aid interpretation. Results: In total, 5223 articles were screened using the PCC acronym (Population, Concept, Context) with 74 included in the final analysis. Assessments included the King-Devick (KD) (n = 34), vestibular-ocular motor screening (VOMs) and/or near point of convergence (NPC) (n = 25), and various alternative tools and technologies (n = 20). The KD met RSR, but RSDA beyond amateur sport was limited. NPC met RSR but did not have RSDA to identify SRCs. The VOMs had conflicting RSR for total score and did not meet RSR in its individual tests. The VOMs total score did perform well in RSDA for SRCs. No alternative tool or technology met both RSR and RSDA. Conclusion: Ocular tools are useful, rapid screening tools but should remain within a multi-modal assessment for SRCs at this time.

Mild hunger elicits attentional desensitization to visual food cues in healthy, non-obese individuals.

Introduction: Food is a vital human need, and the human visual system is finely tuned to detect and respond to food cues in the environment. The omnipresence of food cues across various settings has been linked to the prevalence of obesity in susceptible populations. However, the influence of the post-prandial state on visual attention to food stimuli remains poorly understood. This study aimed to elucidate how a 12 hour fast affects visual attention to food and non-food stimuli in healthy, non-obese individuals. Methods: Visual attention was assessed by measuring the total duration of visual fixations on stimuli presented on a computer screen, using a screen-based eye tracker (Tobii X2-60). Participants were divided into two groups: those who had fasted for 12 hours and those tested within two hours after consuming breakfast (satiated state). Additionally, performance on the Food Stroop task and electrodermal activity (EDA) responses were measured to evaluate attentional interference and physiological arousal, respectively. Salivary samples were also collected to assess levels of alpha-amylase and cortisol. Results: Fasted participants exhibited a progressive decline in visual attention toward food stimuli compared to satiated individuals, reflecting a satiated state. This effect was independent of the palatability of the depicted food items and was not observed with stimuli representing non-food items. The Food Stroop task revealed no differences between fasting and satiated participants, indicating that the presence of food-related stimuli does not differentially impact attentional interference under varying hunger states. Moreover, no significant variations were observed in EDA responses across participant groups and stimulus types, suggesting that the modulation of visual attention to food cues by hunger is independent of physiological arousal. Interestingly, satiated subjects exhibited higher levels of salivary alpha-amylase, which was inversely related to their subjective hunger ratings. No differences in salivary cortisol levels were found between groups. Discussion: The findings indicate a novel influence of mild hunger on the processing of visual food cues, independent of physiological arousal. The decline in visual attention to food stimuli in fasted individuals suggests that satiety modulates visual processing. The lack of differences in attentional interference and physiological arousal between fasting and satiated states further supports the notion that visual attention to food cues is primarily driven by hunger-related mechanisms rather than stress. Additionally, the inverse relationship between salivary alpha-amylase levels and hunger ratings implies that alpha-amylase may serve as a marker of satiety rather than stress.

Examining gaze behavior in undergraduate students and educators during the evaluation of tooth preparation: an eye-tracking study.

BACKGROUND: Gaze behavior can serve as an objective tool in undergraduate pre-clinical dental education, helping to identify key areas of interest and common pitfalls in the routine evaluation of tooth preparations. Therefore, this study aimed to investigate the gaze behavior of undergraduate dental students and dental educators while evaluating a single crown tooth preparation. METHODS: Thirty-five participants volunteered to participate in the study and were divided into a novice group (dental students, n = 18) and an expert group (dental educators, n = 17). Each participant wore a binocular eye-tracking device, and the total duration of fixation was evaluated as a metric to study the gaze behavior. Sixty photographs of twenty different tooth preparations in three different views (buccal, lingual, and occlusal) were prepared and displayed during the experimental session. The participants were asked to rate the tooth preparations on a 100 mm visual analog rating scale and were also asked to determine whether each tooth preparation was ready to make an impression. Each view was divided into different areas of interest. Statistical analysis was performed with a three-way analysis of the variance model with repeated measures. RESULTS: Based on the participants' mean rates, the "best" and the "worst" tooth preparations were selected for analysis. The results showed a significantly longer time to decision in the novices compared to the experts (P = 0.003) and a significantly longer time to decision for both the groups in the best tooth preparation compared to the worst tooth preparation (P = 0.002). Statistical analysis also showed a significantly longer total duration of fixations in the margin compared to all other conditions for both the buccal (P < 0.012) and lingual (P < 0.001) views. CONCLUSIONS: The current study showed distinct differences in gaze behavior between the novices and the experts during the evaluation of single crown tooth preparation. Understanding differences in gaze behavior between undergraduate dental students and dental educators could help improve tooth preparation skills and provide constructive customized feedback.

Perspective matters in goal-predictive gaze shifts during action observation: Results from 6-, 9-, and 12-month-olds and adults.

Research on goal-predictive gaze shifts in infancy so far has mostly focused on the effect of infants' experience with observed actions or the effect of agency cues that the observed agent displays. However, the perspective from which an action is presented to the infants (egocentric vs. allocentric) has received only little attention from researchers despite the fact that the natural observation of own actions is always linked to an egocentric perspective, whereas the observation of others' actions is often linked to an allocentric perspective. The current study investigated the timing of 6-, 9-, and 12-month-olds' goal-predictive gaze behavior, as well as that of adults, during the observation of simple human grasping actions that were presented from either an egocentric or allocentric perspective (within-participants design). The results showed that at 6 and 9 months of age, the infants predicted the action goal only when observing the action from the egocentric perspective. The 12-month-olds and adults, in contrast, predicted the action in both perspectives. The results therefore are in line with accounts proposing an advantage of egocentric versus allocentric processing of social stimuli, at least early in development. This study is among the first to show this egocentric bias already during the first year of life.

Persistent resampling of external information despite 25 repetitions of the same visual search templates.

We commonly load visual working memory minimally when to-be-remembered information remains available in the external world. In visual search, this is characterised by participants frequently resampling previously encoded templates, which helps minimize cognitive effort and improves task performance. If all search templates have been rehearsed many times, they should become strongly represented in memory, possibly eliminating the benefit of reinspections. To test whether repetition indeed leads to less resampling, participants searched for sets of 1, 2, and 4 continuously available search templates. Critically, each unique set of templates was repeated 25 trials consecutively. Although the number of inspections and inspection durations initially decreased strongly when a template set was repeated, behaviour largely stabilised between the tenth and last repetition: Participants kept resampling templates frequently. In Experiment 2, participants performed the same task, but templates became unavailable after 15 repetitions. Strikingly, accuracy remained high even when templates could not be inspected, suggesting that resampling was not strictly necessary in later repetitions. We further show that seemingly 'excessive' resampling behaviour had no direct within-trial benefit to speed nor accuracy, and did not improve performance on long-term memory tests. Rather, we argue that resampling was partially used to boost metacognitive confidence regarding memory representations. As such, eliminating the benefit of minimizing working memory load does not eliminate the persistence with which we sample information from the external world - although the underlying reason for resampling behaviour may be different.

The influence of gender and body satisfaction on attentional bias among young adults in Hong Kong: An eye-tracking study.

The present study examined gender differences in attentional bias of body images. Using an experimental design, 58 young adults aged 18-29 years (Mage = 20.53) completed self-report measures of body satisfaction, eating pathology and trait appearance comparison before viewing whole body images of thin/muscular and large men/women through an eye tracker. After viewing the images, participants completed self-report measures of body satisfaction and state appearance comparison, BMI was also recorded. Results revealed that higher BMI was associated with reduced body satisfaction. Problematic eating attitudes were associated with greater engagement in appearance comparison, which was linked to lower levels of body satisfaction. Exposure to idealised body images negatively impacted individuals with lower body satisfaction leading to lower levels of body satisfaction post-experiment. Findings provide support for the positive association between body dissatisfaction and attentional bias to idealised bodies in both women and men in a Chinese context.

Impaired Social Attention and Cognitive Empathy in a Paediatric Sample of Children with Symptoms of Anxiety.

Impairments in social cognition, in particular empathy, have been associated with childhood psychopathology, though previous investigations have yielded inconsistent results. Measures of social attention can reveal processes involved in responses to emotional stimuli and highlight deficits in empathy, or emotional biases in those with anxiety. The current study examined symptoms of anxiety, cognitive and affective empathy scores, and eye-gaze patterns in a pediatric sample of children (n = 178; 51-98 months-old) referred by their teachers for emerging psychopathology symptoms at school. We used eye-tracking metrics to capture gaze patterns during a dynamic video task designed to elicit empathic responses. Anxiety symptomology was reported by parents using the Screen for Child Anxiety Related Disorders scale (SCARED). Associations between eye-tracking variables, cognitive and affective empathy, and anxiety scores were analysed dimensionally in accordance with the Research and Domain Criteria (RDoC) framework. Higher levels of anxiety were associated with lower cognitive empathy and shorter first and total fixation durations to the eyes, across emotions (happiness, sadness, fear). No such associations were found between affective empathy and anxiety. Hierarchical multiple regression analyses revealed that across emotion conditions, first fixation duration negatively predicted anxiety scores. Our results indicate that children high in anxiety display cognitive empathy impairments and shorter attention to the eyes. These findings could inform early intervention programs for individuals at risk of developing anxiety disorders, as educating those high in anxiety on ways to identify emotions in others through changes in social attention could help to reduce anxiety.

Visual Behaviour During the Interpretation of Cone-Beam Computed Tomography Images of Traumatic Dental Injuries: An Eye-Tracking Study.

BACKGROUND: This cross-sectional observational study aimed to investigate the visual attention patterns of postgraduate endodontic residents during the interpretation of cone-beam computed tomography (CBCT) scans for traumatic dental injuries (TDIs) using eye-tracking technology. METHODS: A cohort of 10 residents who were recruited from King Abdulaziz University Dental Hospital (KAUDH) underwent interpretation of seven CBCT images of TDIs. Eye-tracking metrics, including dwell time, entry time, end time, and the number of revisits, were recorded and analyzed using nonparametric statistical tests. RESULTS: Eye-tracking data revealed that patients with lateral luxation and extrusive luxation pathologies had the longest mean dwell times (1.82 seconds and 1.50 seconds, respectively). These findings were statistically significant compared to other pathologies (p<0.001). Conversely, horizontal root fractures and periapical radiolucency were identified more quickly by the participants (mean entry times of 6.60 seconds and 8.84 seconds, respectively). CONCLUSIONS: The findings indicate variability in visual attention metrics depending on the type of TDI, suggesting that certain injuries may require more focused attention for accurate diagnosis. Specifically, lateral and extrusive luxation injuries attracted longer dwell times, possibly due to their unique diagnostic challenges. This research provides a basis for future studies aiming to optimize education and training related to CBCT interpretation of traumatic dental injuries.

A shared robot control system combining augmented reality and motor imagery brain-computer interfaces with eye tracking.

Objective: Brain-computer interface (BCI) control systems monitor neural activity to detect the user's intentions, enabling device control through mental imagery. Despite their potential, decoding neural activity in real-world conditions poses significant challenges, making BCIs currently impractical compared to traditional interaction methods. This study introduces a novel motor imagery (MI) BCI control strategy for operating a physically assistive robotic arm, addressing the difficulties of MI decoding from electroencephalogram (EEG) signals, which are inherently non-stationary and vary across individuals. Approach: A proof-of-concept BCI control system was developed using commercially available hardware, integrating MI with eye tracking in an augmented reality (AR) user interface to facilitate a shared control approach. This system proposes actions based on the user's gaze, enabling selection through imagined movements. A user study was conducted to evaluate the system's usability, focusing on its effectiveness and efficiency. Main results:Participants performed tasks that simulated everyday activities with the robotic arm, demonstrating the shared control system's feasibility and practicality in real-world scenarios. Despite low online decoding performance (mean accuracy: 0.52 9, F1: 0.29, Cohen's Kappa: 0.12), participants achieved a mean success rate of 0.83 in the final phase of the user study when given 15 minutes to complete the evaluation tasks. The success rate dropped below 0.5 when a 5-minute cutoff time was selected. Significance: These results indicate that integrating AR and eye tracking can significantly enhance the usability of BCI systems, despite the complexities of MI-EEG decoding. While efficiency is still low, the effectiveness of our approach was verified. This suggests that BCI systems have the potential to become a viable interaction modality for everyday applications in the future.