Attention Allocation in ASD: a Review and Meta-analysis of Eye-Tracking Studies

Deliberate and Self-Conscious Adaptation of Eye-Contact by Autistic Adults

Eye gaze is widely recognised as an important element in managing social interactions, receiving information from others and communicating information about ourselves. Atypical eye gaze is one of the characteristic hallmarks of autism. Experimental research has contributed significantly to our knowledge of eye-gaze in autism, however, there is a lack of research exploring how autistic individuals describe and understand the phenomenological experience of eye-gaze and eye-contact. The current study explores the subjective experience of deliberate and self-conscious adaptation of eye-contact by autistic adults. Nine autistic adults were interviewed individually about their experiences of eye-contact. Audio recordings were transcribed, and analysed using Interpretative Phenomenological Analysis (IPA). Themes included gaining awareness of eye contact differences through feedback from others, the interaction of motivation to make eye-contact with a sense of autistic identity, difficulties listening when making eye contact, the importance of familiarity of conversational partners, and strategies to make eye-contact. This study makes an important and novel contribution to understanding the experience of eye-contact differences from the perspective of autistic adults themselves, highlighting the phenomenology of eye-contact as potentially aversive and the social pressure to engage in it, and exploring factors influencing effective eye-contact, with implications for psychological intervention.

Attention to Social and Non-Social Stimuli in a Continuous Performance Test in Autistic and Typically Developed Participants: An ERP Study

Autism spectrum disorder (ASD) is characterized by a range of symptoms, including restrictive behaviors and deficient social skills. We investigated EEG correlates of social attention, face, and non-face perception by applying a continuous performance test (CPT) with two different sets of stimuli (letters and faces). The CPT required participants to respond to a specific target stimulus (e.g., "X") only when it followed a specific preceding stimulus (e.g., "O"). Event-related potential (ERP) components, including P100, N170, P200, N250, P300, and continuous negative variation (CNV), were analyzed in 19 young adults with ASD and 19 typically developed (TD) individuals that were matched for intelligence, age, and gender. TD participants had higher accuracies only for the target condition and regardless of stimulus type. No ERP differences between the two groups were found for the CPT with letter stimuli. By contrast, autistic individuals exhibited lower amplitudes of P300 and CNV during face CPT. Results suggest diminished allocation of attentional resources and response preparation towards socially relevant face stimuli.

Study protocol for the EYEdentify project: An examination of gaze behaviour in autistic adults using a virtual reality-based paradigm

INTRODUCTION

Autism Spectrum Condition (ASC) is characterised by difficulties in social communication and interaction, which may pose significant challenges to daily functioning throughout life. While current diagnostic methods for ASC often rely on measures based on subjective reports, there is a growing need for objective, quantifiable measures to support current clinical assessment of ASC. Eye-tracking technology records eye and gaze movements in real time and provides a direct and objective method for assessing social attention. Integrating eye-tracking within virtual reality (VR) environments presents a novel approach for capturing gaze behaviour in dynamic, ecologically valid social scenarios. This study aims to investigate whether VR-based eye information can reveal group differences in gaze behaviour between autistic adults and neurotypical controls in simulated social interactions.

METHODS

This case-control study will include 140 adults diagnosed with ASC and 50 neurotypical controls, matched by age and gender. Participants will engage in six VR-based social scenarios, which vary in social complexity and the presence of non-social distractors. Eye information will be measured using eye-tracking technology integrated into a head-mounted display. Gaze behaviour will be analysed through fixation-based metrics on parameters including number of fixations, mean fixation time, and dwell time, on predetermined Areas of Interest.

ANALYSIS

Statistical analyses will assess between-group differences in gaze behaviour as well as correlations between gaze metrics and clinical measures of social functioning, social cognition and symptom severity.

DISCUSSION

This study utilises VR-based eye-tracking to investigate novel paradigms for assessing gaze behaviour in ASC in immersive, interactive environments and aims to advance the current understanding of visual social attention in ASC. Positive outcomes from this study may support further research into VR-based eye-tracking to supplement existing clinical assessment methods.

Translational research approach to social orienting deficits in autism: the role of superior colliculus-ventral tegmental pathway

Autism Spectrum Disorder (ASD) is characterized by impairments in social interaction and repetitive behaviors. A key characteristic of ASD is a decreased interest in social interactions, which affects individuals' ability to engage with their social environment. This study explores the neurobiological basis of these social deficits, focusing on the pathway between the Superior Colliculus (SC) and the Ventral Tegmental Area (VTA). Adopting a translational approach, our research used Shank3 knockout mice (Shank3-/-), which parallel a clinical cohort of young children with ASD, to investigate these mechanisms. We observed consistent deficits in social orienting across species. In children with ASD, fMRI analyses revealed a significant decrease in connectivity between the SC and VTA. Additionally, using miniscopes in mice, we identified a reduction in the frequency of calcium transients in SC neurons projecting to the VTA, accompanied by changes in neuronal correlation and intrinsic cellular properties. Notably, the interneuronal correlation in Shank3-/- mice and the functional connectivity of the SC to VTA pathway in children with ASD correlated with the severity of social deficits. Our findings underscore the potential of the SC-VTA pathway as a biomarker for ASD and open new avenues for therapeutic interventions, highlighting the importance of early detection and targeted treatment strategies.

Correlation Between Gaze Behaviors and Social Communication Skills of Young Autistic Children: A Meta-Analysis of Eye-Tracking Studies

This meta-analysis examined correlations between eye-tracking measures of gaze behaviors manifested during dynamic salient social stimuli and behavioral assessment measures of social communication skills of young autistic children. We employed a multilevel model with random effects to perform three separate meta-analyses for correlation between social communication skills and (a) all gaze behaviors, (b) gaze duration, and (c) gaze transition. Subsequently, we performed meta-regression to assess the role of four moderators, including age, continuum of naturalness of stimuli, gaze metric, and area of interest, on correlation effect sizes that were heterogeneous at the population level. A total of 111 correlation coefficients from 17 studies for 1132 young autistic children or children with high-likelihood for autism (Mage range = 6-95 months) were included in this meta-analysis. The correlation effect sizes for all three meta-analyses were significant, supporting the relation between improved gaze behaviors and better social communication skills. In addition, age, gaze metric, and area of interest were significant moderators. This suggests the importance of identifying meaningful gaze behaviors related to social communication skills and the increasingly influential role of gaze behaviors in shaping social communication skills as young autistic children progress through the early childhood stage. The continuum of naturalness of stimuli, however, was revealed to trend towards having a significant moderating effect. Lastly, it is important to note the evidence of potential publication bias. Our findings are discussed in the context of early identification and intervention and unraveling the complex nature of autism.

Early selective attention to the articulating mouth as a potential female-specific marker of better language development in autism: a review

Autism is a neurodevelopmental condition with early onset, usually entailing language differences compared to neurotypical peers. Females are four times less likely than males to be diagnosed with autism, and the language features associated with this condition are less frequent in females than in males. However, the developmental mechanisms underlying these sex differences remain unclear. In neurotypical populations, sex differences in language development are also observable from early on, with females outperforming males. One mechanism underlying these sex differences may be early differences in selective attention to talking faces. During the first year, more mouth-looking generally predicts better language development, but sex differences exist. Female infants look at the mouth of a talking face more than males without penalizing looking to the eyes, and reduced mouth-looking in early infancy relates to better vocabulary in toddlerhood only in females. In this hypothesis and theory article, we propose that unique female gaze patterns to the mouth may constitute an early female-specific candidate marker that acts as a protective marker for language development also in autism. Since autism is highly heritable, investigating infants at elevated likelihood for autism offers the opportunity to search for sex-specific markers operating early in life before autistic features and language differences emerge. We argue that, as in neurotypical female infants, mouth-looking may also protect female infants-at-elevated-likelihood-for-autism population from potential later differences in language skills. If so, then sex-specific early behavioral markers, potentially acting as protective markers of language, may compensate for some genetic risk markers affecting this population. Here we gather evidence from neurotypical infants and those with elevated likelihood of autism to uncover why biological sex, the development of selective attention to the mouth, and language acquisition could be intimately related in both populations. We also propose hypotheses regarding potential sex-differentiated neurodevelopmental pathways. We end discussing future research challenges: how generalizable mouth-looking could be as a potential female-specific early language marker across contexts (experimental vs. real life), countries, and developmental time. Ultimately, we aim to target a novel protective candidate of language acquisition, informing tailored interventions that consider sex as an important source of individual variability.

Auditory Global-Local Processing Under Tonal Language Background: Effect of Attention and Autistic Traits

PURPOSE

Neurotypical individuals show a robust "global precedence effect (GPE)" when processing hierarchically structured visual information. However, the auditory domain remains understudied. The current research serves to fill the knowledge gap on auditory global-local processing across the broader autism phenotype under the tonal language background.

METHOD

This study examined auditory global-local processing styles in 37 Mandarin-speaking young adults (age: M = 20.35, SD = 2.32; 19 males) with varying autistic traits. The participants were required to judge global and local pitch structures in nine-tone melodies with both congruent and incongruent conditions under both directed attention and divided attention modes.

RESULTS

We found that GPE persisted independent of the attention modes during hierarchical processing. Autistic traits were among the potential contributors that reshaped GPE in auditory global-local processing under a tonal language background.

CONCLUSIONS

Our study provides an initial investigation into auditory global-local processing among Mandarin-speaking individuals across a range of autistic traits, revealing the presence of the GPE effect during hierarchical pitch structure processing. The advantage of global processing versus local processing expanded with increasing autistic traits, providing further support for the notion that auditory global processing may remain intact in autism and the broader phenotype. We highlight that GPE is a process of coarse-to-fine integration of sensory perception and cognitive feedback iteration, which both top-down and bottom-up processes wield influence on. These findings have implications for the study of atypical auditory processing in autism and may help to refine the early diagnosis and auditory-based intervention for autism.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.28114118.

A systematic review and meta-analysis of atypical visual attention towards non-social stimuli in preschoolers with autism spectrum disorder

Research on attention towards non-social stimuli in preschoolers with autism spectrum disorder (ASD) has increased over the past decade; however, findings have been inconsistent. It has been suggested that stimuli relating to common circumscribed interests (CIs) elicit more attention than non-CI related stimuli. This meta-analysis synthesizes results from 31 studies that compared attention towards non-social stimuli in children with ASD under the age of five with typically developing (TD) controls using eye-tracking. Additional subgroup analysis comparing studies that employed non-social stimuli related to CIs frequently reported in adults with ASD to studies using non-CI related stimuli were conducted. Meta-regressions with age, sex, stimulus dimension, nonverbal DQ, and symptom severity were conducted. Results show small (g = 0.39) but significantly higher attention towards non-social stimuli for the ASD group. However, when studies were split based on stimulus type no significant differences for non-CI related stimuli was found. Meanwhile studies employing CI related stimuli reported significant large effects on attention allocation (g = 0.69). None of the conducted regressions reached significance. The findings show increased non-social attention in children with ASD is driven by CI related content rather than a general non-social attentional bias. The findings and future research directions are discussed.

Early- and Late-Stage Auditory Processing of Speech Versus Non-Speech Sounds in Children With Autism Spectrum Disorder: An ERP and Oscillatory Activity Study

Individuals with autism spectrum disorder (ASD) often exhibit greater sensitivity to non-speech sounds, reduced sensitivity to speech, and increased variability in cortical activity during auditory speech processing. We assessed differences in cortical responses and variability in early and later processing stages of auditory speech versus non-speech sounds in typically developing (TD) children and children with ASD. Twenty-eight 4- to 9-year-old children (14 ASDs) listened to speech and non-speech sounds during an electroencephalography session. We measured peak amplitudes for early (P2) and later (P3a) stages of auditory processing and inter-trial theta phase coherence as a marker of cortical variability. TD children were more sensitive to speech sounds during early and later processing stages than ASD children, reflected in larger P2 and P3a amplitudes. Individually, twice as many TD children showed reliable differentiation between speech and non-speech sounds compared to children with ASD. Children with ASD showed greater intra-individual variability in theta responses to speech sounds during early and later processing stages. Children with ASD show atypical auditory processing of fundamental speech sounds, perhaps due to reduced and more variable cortical activation. These atypicalities in the consistency of cortical responses to fundamental speech features may impact the development of cortical networks and have downstream effects on more complex forms of language processing.

How 18-month-olds with Later Autism Look at Other Children Interacting: The Timing of Gaze Allocation

When observing other people during naturally paced and dynamic interactions, it is essential to look at specific locations at the right time to extract a maximum of socially informative content. In this study, we aimed to investigate the looking behavior of typically developing toddlers and toddlers later diagnosed with autism when observing other children interact. The sample consisted of 98 toddlers; 22 in a low-likelihood of autism group, 60 in an elevated likelihood of autism group who did not receive a subsequent diagnosis, and 16 in an elevated likelihood group who did receive an autism diagnosis. Participants performed an eye tracking task at 18 months of age and were assessed for diagnostic outcome at 36 months. The video stimuli consisted of two children interacting, where a boy reaches out for a toy and a girl refuses to give it to him. The low likelihood group showed an expected increase in ratio of looking at the girl's face after the boy requested the toy, as compared to before (t(21) = -3.337, p = .003). Toddlers with later autism showed a significantly lower ratio of looking at the girl's face during this time window, as compared to the other groups (F(2,91) = 3.698, p = .029). These findings provide new leads on how social gaze may be different in children with autism in everyday life (e.g., kindergarten), and highlight the need of studying the dynamics of gaze on short time scales.

Social and joint attention during shared book reading in young autistic children: a potential marker for social development

BACKGROUND

Atypical patterns of social engagement and joint attention behaviors are diagnostic criteria for people with autism spectrum disorder. Experimental tasks using eye-tracking methodologies have, however, shown inconsistent results. The development of tasks with greater ecological validity and relevance for developmentally appropriate social milestones has been identified as important for the field.

METHODS

We developed a novel, dynamic eye-tracking task emulating a shared book reading (SBR) scenario. Four SBR videos of an adult reader engaging with the viewer while reading a children's picture book and including sequenced bids for joint attention were developed. Participants included 90 children (N = 56 autistic children, N = 34 neurotypical children; aged 3-12). Social attention was also measured in a live free play task between participants and an experimenter.

RESULTS

Compared to neurotypical children, autistic children displayed reduced attention to socially salient stimuli including the reader's face and picture book across SBR videos and during joint attention bids specifically. In contrast, they showed increased attention to nonsalient background stimuli compared to their neurotypical peers. These attention patterns in autistic children were associated with reduced verbal and nonverbal cognitive skills and increased symptoms associated with autism. Interestingly, positive correlations in the frequency of eye gaze between SBR and free play suggested a potential predictive value for social attention in live social interactions.

CONCLUSIONS

Findings highlight the utility of SBR eye-tracking tasks in understanding underlying divergences in social engagement and joint attention between autistic and neurotypical children. This commonly practiced early childhood activity may provide insights into the relationship between social engagement and learning to reveal how such attentional patterns might influence broader developmental and educational outcomes.

A novel end-to-end dual-camera system for eye gaze synchrony assessment in face-to-face interaction

Quantification of face-to-face interaction can provide highly relevant information in cognitive and psychological science research. Current commercial glint-dependent solutions suffer from several disadvantages and limitations when applied in face-to-face interaction, including data loss, parallax errors, the inconvenience and distracting effect of wearables, and/or the need for several cameras to capture each person. Here we present a novel eye-tracking solution, consisting of a dual-camera system used in conjunction with an individually optimized deep learning approach that aims to overcome some of these limitations. Our data show that this system can accurately classify gaze location within different areas of the face of two interlocutors, and capture subtle differences in interpersonal gaze synchrony between two individuals during a (semi-)naturalistic face-to-face interaction.

Smartphone-based gaze estimation for in-home autism research

Atypical gaze patterns are a promising biomarker of autism spectrum disorder. To measure gaze accurately, however, it typically requires highly controlled studies in the laboratory using specialized equipment that is often expensive, thereby limiting the scalability of these approaches. Here we test whether a recently developed smartphone-based gaze estimation method could overcome such limitations and take advantage of the ubiquity of smartphones. As a proof-of-principle, we measured gaze while a small sample of well-assessed autistic participants and controls watched videos on a smartphone, both in the laboratory (with lab personnel) and in remote home settings (alone). We demonstrate that gaze data can be efficiently collected, in-home and longitudinally by participants themselves, with sufficiently high accuracy (gaze estimation error below 1° visual angle on average) for quantitative, feature-based analysis. Using this approach, we show that autistic individuals have reduced gaze time on human faces and longer gaze time on non-social features in the background, thereby reproducing established findings in autism using just smartphones and no additional hardware. Our approach provides a foundation for scaling future research with larger and more representative participant groups at vastly reduced cost, also enabling better inclusion of underserved communities.

Influence of autistic traits and communication role on eye contact behavior during face-to-face interaction

Eye contact is a central component in face-to-face interactions. It is important in structuring communicative exchanges and offers critical insights into others' interests and intentions. To better understand eye contact in face-to-face interactions, we applied a novel, non-intrusive deep-learning-based dual-camera system and investigated associations between eye contact and autistic traits as well as self-reported eye contact discomfort during a referential communication task, where participants and the experimenter had to guess, in turn, a word known by the other individual. Corroborating previous research, we found that participants' eye gaze and mutual eye contact were inversely related to autistic traits. In addition, our findings revealed different behaviors depending on the role in the dyad: listening and guessing were associated with increased eye contact compared with describing words. In the listening and guessing condition, only a subgroup who reported eye contact discomfort had a lower amount of eye gaze and eye contact. When describing words, higher autistic traits were associated with reduced eye gaze and eye contact. Our data indicate that eye contact is inversely associated with autistic traits when describing words, and that eye gaze is modulated by the communicative role in a conversation.

Attention toward Social and Non-Social Stimuli in Preschool Children with Autism Spectrum Disorder: A Paired Preference Eye-Tracking Study

Different dimensions of visual attention to social (human faces) and non-social stimuli (objects) were assessed in 19 preschool children with Autism Spectrum Disorder (ASD) and 19 typically developing (TD) age, gender, and IQ-matched controls through an original paired preference eye-tracking paradigm. The present study found a significantly reduced attentional bias toward human faces in children with ASD compared to TD controls. The analysis of the total fixation time showed a significantly reduced preference for faces in children with ASD compared to TD children. Moreover, while TD children showed a significant preference for the face over the object, children in the ASD group observed the two paired pictures for a similar amount of time, thus showing no preference. Besides, children with ASD paid significantly more sustained attention to the objects than TD children. Children in the TD group paid greater sustained attention to the faces over the objects, while children in the ASD group did not differentiate between objects and faces. Finally, an age effect was found in ASD, as younger children in the group tended to prefer objects and to show more sustained attention towards them. Overall, these findings add to the literature on anomalies in attention toward social and non-social stimuli in young children with ASD compared to their TD counterparts. These results are discussed in the light of previous studies and suggest possible directions for future research.

People with Autism Spectrum Disorder Could Interact More Easily with a Robot than with a Human: Reasons and Limits

Individuals with Autism Spectrum Disorder show deficits in communication and social interaction, as well as repetitive behaviors and restricted interests. Interacting with robots could bring benefits to this population, notably by fostering communication and social interaction. Studies even suggest that people with Autism Spectrum Disorder could interact more easily with a robot partner rather than a human partner. We will be looking at the benefits of robots and the reasons put forward to explain these results. The interest regarding robots would mainly be due to three of their characteristics: they can act as motivational tools, and they are simplified agents whose behavior is more predictable than that of a human. Nevertheless, there are still many challenges to be met in specifying the optimum conditions for using robots with individuals with Autism Spectrum Disorder.

Oculomotor randomness is higher in autistic children and increases with the severity of symptoms

A variety of studies have suggested that at least some children with autism spectrum disorder (ASD) view the world differently. Differences in gaze patterns as measured by eye tracking have been demonstrated during visual exploration of images and natural viewing of movies with social content. Here we analyzed the temporal randomness of saccades and blinks during natural viewing of movies, inspired by a recent measure of "randomness" applied to micro-movements of the hand and head in ASD (Torres et al., 2013; Torres & Denisova, 2016). We analyzed a large eye-tracking dataset of 189 ASD and 41 typically developing (TD) children (1-11 years old) who watched three movie clips with social content, each repeated twice. We found that oculomotor measures of randomness, obtained from gamma parameters of inter-saccade intervals (ISI) and blink duration distributions, were significantly higher in the ASD group compared with the TD group and were correlated with the ADOS comparison score, reflecting increased "randomness" in more severe cases. Moreover, these measures of randomness decreased with age, as well as with higher cognitive scores in both groups and were consistent across repeated viewing of each movie clip. Highly "random" eye movements in ASD children could be associated with high "neural variability" or noise, poor sensory-motor control, or weak engagement with the movies. These findings could contribute to the future development of oculomotor biomarkers as part of an integrative diagnostic tool for ASD.

Autism symptoms, functional impairments, and gaze fixation measured using an eye-tracker in 6-year-old children

Introduction

Autism spectrum disorder (ASD) is a neurodevelopmental disorder clinically characterized by abnormalities in eye contact during social exchanges. We aimed to clarify whether the amount of gaze fixation, measured at the age of 6 years using Gazefinder, which is an established eye-tracking device, is associated with ASD symptoms and functioning.

Methods

The current study included 742 participants from the Hamamatsu Birth Cohort Study. Autistic symptoms were evaluated according to the Autism Diagnostic Observation Schedule, Second Edition (ADOS-2), and the functioning of the participating children in real life was assessed using the Japanese version of the Vineland Adaptive Behavior Scales, Second Edition (VABS-II). The Gazefinder system was used for gaze fixation rates; two areas of interest (eyes and mouth) were defined in a talking movie clip, and eye gaze positions were calculated through corneal reflection techniques.

Results

The participants had an average age of 6.06 ± 0.14 years (males: 384; 52%). According to ADOS, 617 (83%) children were assessed as having none/mild ASD and 51 (7%) as severe. The average VABS-II scores were approximately 100 (standard deviation = 12). A higher gaze fixation rate on the eyes was associated with a significantly lower likelihood of the child being assigned to the severe ADOS group after controlling for covariates (odds ratio [OR], 0.02; 95% confidence interval [CI], 0.002-0.38). The gaze fixation rate on the mouth was not associated with ASD symptoms. A higher gaze fixation rate on the mouth was associated with a significantly lower likelihood of the child being assigned to the low score group in VABS-II socialization after controlling for covariates (OR, 0.18; 95% CI, 0.04-0.85). The gaze fixation rate on the eyes was not associated with functioning.

Conclusion

We found that children with low gaze fixation rates on the eyes were likely to have more ASD symptoms, and children with low gaze fixation rates on the mouth were likely to demonstrate poorer functioning in socialization. Hence, preschool children could be independently assessed in the general population for clinically relevant endophenotypes predictive of ASD symptoms and functional impairments.

Effects of Transcranial Direct Current Stimulation on Social Attention Patterns and Emotion Recognition Ability in Male Adolescents with Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is characterized by impairments in social cognition including emotion recognition (ER) abilities. Common symptoms include unusual patterns of visual social attention, which are investigated as early developmental biomarkers for ASD. Transcranial Direct Current Stimulation (tDCS) has shown promising results in influencing social functioning in individuals with ASD. However, the effects of tDCS on social attention patterns and ER ability in adolescents with ASD remain unclear. This double-blind, sham-controlled, randomized clinical trial examined the effects of repeated sessions of tDCS on gaze behavior and ER ability in 22 male adolescents diagnosed with ASD. Participants received either 20 min of 2 mA active tDCS or sham stimulation for 10 days and an intra-stimulation training. Social allocation patterns were assessed using eye-tracking paradigms, including ER tasks. Our results indicated no tDCS-specific effects. Both groups showed improvements in ER and more frequent, faster, and longer fixations on the eyes than the mouth, and on social than nonsocial areas. In tasks with low social content, fixating the mouth seemed to increase ER accuracy. Understanding the effects of tDCS on social functioning in adolescents with ASD holds promise for the development of targeted interventions to improve their social cognition abilities.

Relational memory weakness in autism despite the use of a controlled encoding task

Introduction

Recent work challenged past findings that documented relational memory impairments in autism. Previous studies often relied solely on explicit behavioral responses to assess relational memory integrity, but successful performance on behavioral tasks may rely on other cognitive abilities (e.g., executive functioning) that are impacted in some autistic individuals. Eye-tracking tasks do not require explicit behavioral responses, and, further, eye movements provide an indirect measure of memory. The current study examined whether memory-specific viewing patterns toward scenes differ between autistic and non-autistic individuals.

Methods

Using a long-term memory paradigm that equated for complexity between item and relational memory tasks, participants studied a series of scenes. Following the initial study phase, scenes were re-presented, accompanied by an orienting question that directed participants to attend to either features of an item (i.e., in the item condition) or spatial relationships between items (i.e., in the relational condition) that might be subsequently modified during test. At test, participants viewed scenes that were unchanged (i.e., repeated from study), scenes that underwent an "item" modification (an exemplar switch) or a "relational" modification (a location switch), and scenes that had not been presented before. Eye movements were recorded throughout.

Results

During study, there were no significant group differences in viewing directed to regions of scenes that might be manipulated at test, suggesting comparable processing of scene details during encoding. However, there was a group difference in explicit recognition accuracy for scenes that underwent a relational change. Marginal group differences in the expression of memory-based viewing effects during test for relational scenes were consistent with this behavioral outcome, particularly when analyses were limited to scenes recognized correctly with high confidence. Group differences were also evident in correlational analyses that examined the association between study phase viewing and recognition accuracy and between performance on the Picture Sequence Memory Test and recognition accuracy.

Discussion

Together, our findings suggest differences in the integrity of relational memory representations and/or in the relationships between subcomponents of memory in autism.

Familiarization with Mixed Reality for Individuals with Autism Spectrum Disorder: An Eye Tracking Study

Mixed Reality (MR) technology is experiencing significant growth in the industrial and healthcare sectors. The headset HoloLens 2 displays virtual objects (in the form of holograms) in the user's environment in real-time. Individuals with Autism Spectrum Disorder (ASD) exhibit, according to the DSM-5, persistent deficits in communication and social interaction, as well as a different sensitivity compared to neurotypical (NT) individuals. This study aims to propose a method for familiarizing eleven individuals with severe ASD with the HoloLens 2 headset and the use of MR technology through a tutorial. The secondary objective is to obtain quantitative learning indicators in MR, such as execution speed and eye tracking (ET), by comparing individuals with ASD to neurotypical individuals. We observed that 81.81% of individuals with ASD successfully familiarized themselves with MR after several sessions. Furthermore, the visual activity of individuals with ASD did not differ from that of neurotypical individuals when they successfully familiarized themselves. This study thus offers new perspectives on skill acquisition indicators useful for supporting neurodevelopmental disorders. It contributes to a better understanding of the neural mechanisms underlying learning in MR for individuals with ASD.

Game-Based Social Interaction Platform for Cognitive Assessment of Autism Using Eye Tracking

The design goals of recently developed serious games are to improve attention, affective recognition, and social interactions among individuals with autism. However, most previous studies on serious games used behavioral questionnaires to evaluate their effectiveness. The cognitive assessment of individuals with autism after behavioral intervention or drug treatment has become important because it provides promising biomarkers to assess improvement after cognitive intervention. In this study, we developed a game-based social interaction platform incorporating an eye-tracking system for children and preadolescents with autism. Three modules (focusing on gaze following, facial emotion recognition, and social interaction skills) are included in the platform; participants with autism learn these according to their cognitive abilities. The eye-tracking results showed decreased fixation durations when autistic children looked at positive emotional expressions and focused on multiple targets. Prolonged saccade durations and shorter fixation times for social-related facial emotion expressions were also found in preadolescents and teenagers with autism. Our findings suggest that these atypical gaze patterns are reliable biomarkers for evaluating the social and cognitive functions of autistic individuals while playing serious games. The proposed platform's game-based modules and the findings regarding aberrant gaze patterns in autistic individuals demonstrate the possibility of evaluating cognitive functions and intervention effectiveness by using eye-tracking signals in a serious game or real-life environment.

Preferential looking to eyes versus mouth in early infancy: heritability and link to concurrent and later development

BACKGROUND

From birth, infants orient preferentially to faces, and when looking at the face, they attend primarily to eyes and mouth. These areas convey different types of information, and earlier research suggests that genetic factors influence the preference for one or the other in young children.

METHODS

In a sample of 535 5-month-old infant twins, we assessed eye (relative to mouth) preference in early infancy, i.e., before neural systems for social communication and language are fully developed. We investigated the contribution of genetic and environmental factors to the preference for looking at eyes, and the association with concurrent traits and follow-up measures.

RESULTS

Eye preference was independent from all other concurrent traits measured, and had a moderate-to-high contribution from genetic influences (A = 0.57; 95% CI: 0.45, 0.66). Preference for eyes at 5 months was associated with higher parent ratings of receptive vocabulary at 14 months. No statistically significant association with later autistic traits was found. Preference for eyes was strikingly stable across different stimulus types (e.g., dynamic vs. still), suggesting that infants' preference at this age does not reflect sensitivity to low-level visual cues.

CONCLUSIONS

These results suggest that individual differences in infants' preferential looking to eyes versus mouth to a substantial degree reflect genetic variation. The findings provide new leads on both the perceptual basis and the developmental consequences of these attentional biases.

"Unattended, distracting or irrelevant": Theoretical implications of terminological choices in auditory selective attention research

For seventy years, auditory selective attention research has focused on studying the cognitive mechanisms of prioritizing the processing a 'main' task-relevant stimulus, in the presence of 'other' stimuli. However, a closer look at this body of literature reveals deep empirical inconsistencies and theoretical confusion regarding the extent to which this 'other' stimulus is processed. We argue that many key debates regarding attention arise, at least in part, from inappropriate terminological choices for experimental variables that may not accurately map onto the cognitive constructs they are meant to describe. Here we critically review the more common or disruptive terminological ambiguities, differentiate between methodology-based and theory-derived terms, and unpack the theoretical assumptions underlying different terminological choices. Particularly, we offer an in-depth analysis of the terms 'unattended' and 'distractor' and demonstrate how their use can lead to conflicting theoretical inferences. We also offer a framework for thinking about terminology in a more productive and precise way, in hope of fostering more productive debates and promoting more nuanced and accurate cognitive models of selective attention.

Reduced social attention in autism is magnified by perceptual load in naturalistic environments

Individuals with autism spectrum conditions (ASC) describe differences in both social cognition and sensory processing, but little is known about the causal relationship between these disparate functional domains. In the present study, we sought to understand how a core characteristic of autism-reduced social attention-is impacted by the complex multisensory signals present in real-world environments. We tested the hypothesis that reductions in social attention associated with autism would be magnified by increasing perceptual load (e.g., motion, multisensory cues). Adult participants (N = 40; 19 ASC) explored a diverse set of 360° real-world scenes in a naturalistic, active viewing paradigm (immersive virtual reality + eyetracking). Across three conditions, we systematically varied perceptual load while holding the social and semantic information present in each scene constant. We demonstrate that reduced social attention is not a static signature of the autistic phenotype. Rather, group differences in social attention emerged with increasing perceptual load in naturalistic environments, and the susceptibility of social attention to perceptual load predicted continuous measures of autistic traits across groups. Crucially, this pattern was specific to the social domain: we did not observe differential impacts of perceptual load on attention directed toward nonsocial semantic (i.e., object, place) information or low-level fixation behavior (i.e., overall fixation frequency or duration). This study provides a direct link between social and sensory processing in autism. Moreover, reduced social attention may be an inaccurate characterization of autism. Instead, our results suggest that social attention in autism is better explained by "social vulnerability," particularly to the perceptual load of real-world environments.

Idiosyncratic viewing patterns of social scenes reflect individual preferences

In general, humans preferentially look at conspecifics in naturalistic images. However, such group-based effects might conceal systematic individual differences concerning the preference for social information. Here, we investigated to what degree fixations on social features occur consistently within observers and whether this preference generalizes to other measures of social prioritization in the laboratory as well as the real world. Participants carried out a free viewing task, a relevance taps task that required them to actively select image regions that are crucial for understanding a given scene, and they were asked to freely take photographs outside the laboratory that were later classified regarding their social content. We observed stable individual differences in the fixation and active selection of human heads and faces that were correlated across tasks and partly predicted the social content of self-taken photographs. Such relationship was not observed for human bodies indicating that different social elements need to be dissociated. These findings suggest that idiosyncrasies in the visual exploration and interpretation of social features exist and predict real-world behavior. Future studies should further characterize these preferences and elucidate how they shape perception and interpretation of social contexts in healthy participants and patients with mental disorders that affect social functioning.

Eye Tracking Study of Social Intensity on Social Orientation of Autistic Children

Some previous studies indicate that impaired social attention mainly results in social disorders in autistic children. In the social attention mode of autistic children, social orientation and joint attention are particularly important. The influence of different social intensity and ecological validity on them are worthy of further study. This study used realistic paintings with moderate ecological validity as experimental materials, to design isolated individual scene and social interaction scene, and to explore the impact of social interaction on the social orientation of autistic children. It found that in the scenes without social interaction, the attention patterns of autistic children and typical developing children were the same, while the attention patterns of autistic children were abnormal in the scenes with social interaction. From the eye tracking data, it was shown that the gaze processing process of autistic children was not as smooth as that of typical developing children. Compared with cartoons and other social scenes with low ecological validity, realistic painting could better restore the proportion of real scenes. Moreover, it could reduce the complexity of information which could not be done in real scenes. The findings of this study provide support for training and education of autistic children. Intervention with realistic paintings is conducive to the migration of autistic children.

Gaze and social functioning associations in autism spectrum disorder: A systematic review and meta-analysis

Autism spectrum disorder (ASD) is characterized by significant social functioning impairments, including (but not limited to) emotion recognition, mentalizing, and joint attention. Despite extensive investigation into the correlates of social functioning in ASD, only recently has there been focus on the role of low‐level sensory input, particularly visual processing. Extensive gaze deficits have been described in ASD, from basic saccadic function through to social attention and the processing of complex biological motion. Given that social functioning often relies on accurately processing visual information, inefficient visual processing may contribute to the emergence and sustainment of social functioning difficulties in ASD. To explore the association between measures of gaze and social functioning in ASD, a systematic review and meta‐analysis was conducted. A total of 95 studies were identified from a search of CINAHL Plus, Embase, OVID Medline, and psycINFO databases in July 2021. Findings support associations between increased gaze to the face/head and eye regions with improved social functioning and reduced autism symptom severity. However, gaze allocation to the mouth appears dependent on social and emotional content of scenes and the cognitive profile of participants. This review supports the investigation of gaze variables as potential biomarkers of ASD, although future longitudinal studies are required to investigate the developmental progression of this relationship and to explore the influence of heterogeneity in ASD clinical characteristics.

Emotion Facial Processing in Children With Autism Spectrum Disorder: A Pilot Study of the Impact of Service Dogs

Processing and recognizing facial expressions are key factors in human social interaction. Past research suggests that individuals with autism spectrum disorder (ASD) present difficulties to decode facial expressions. Those difficulties are notably attributed to altered strategies in the visual scanning of expressive faces. Numerous studies have demonstrated the multiple benefits of exposure to pet dogs and service dogs on the interaction skills and psychosocial development of children with ASD. However, no study has investigated if those benefits also extend to the processing of facial expressions. The aim of this study was to investigate if having a service dog had an influence on facial expression processing skills of children with ASD. Two groups of 15 children with ASD, with and without a service dog, were compared using a facial expression recognition computer task while their ocular movements were measured using an eye-tracker. While the two groups did not differ in their accuracy and reaction time, results highlighted that children with ASD owning a service dog directed less attention toward areas that were not relevant to facial expression processing. They also displayed a more differentiated scanning of relevant facial features according to the displayed emotion (i.e., they spent more time on the mouth for joy than for anger, and vice versa for the eyes area). Results from the present study suggest that having a service dog and interacting with it on a daily basis may promote the development of specific visual exploration strategies for the processing of human faces.

The salience of competing nonsocial objects reduces gaze toward social stimuli, but not the eyes, more in typically developing than autistic boys

Decreased attention to social information is considered an early emerging symptom of autism spectrum disorder (ASD), although the underlying causes remain controversial. Here we explored the impact of nonsocial object salience on reduced attention to social stimuli in male ASD compared with typically developing (TD) children. Correlations with blood concentrations of neuropeptides linked with social cognition were also investigated. Eye-tracking was performed in 102 preschool-aged boys (50 ASD, 52 TD) using a paradigm with social (faces) versus nonsocial (objects) stimuli presented in pairs in two conditions where nonsocial stimulus salience was varied. Basal oxytocin (OXT) and vasopressin concentrations were measured in blood. Compared with TD boys those with ASD viewed social stimuli less only when they were paired with low-salience nonsocial objects. Additionally, boys with ASD spent less time than TD ones viewing facial features, particularly the eyes. In TD boys, OXT concentrations and cognitive development scores were positively associated with time spent viewing the eye region, whereas for boys with ASD associations with time spent viewing faces were negative. Reduced gaze toward social stimuli in ASD relative to TD individuals may therefore be influenced by how salient the paired nonsocial objects are for the latter. On the other hand, reduced interest in the eyes of faces in boys with ASD is not influenced by how salient competing nonsocial stimuli are. Basal OXT concentrations and cognitive development scores are predictive of time spent viewing social stimuli in TD boys (eyes) and those with ASD (faces) but in the opposite direction. LAY SUMMARY: Children with autism exhibit reduced attention to social paired with nonsocial stimuli compared to typically developing children. Using eye-tracking we show this difference is due to typically developing rather than autistic boys being more influenced by how interesting competing nonsocial objects are. On the other hand, reduced time looking at the eyes in autistic relative to typically developing boys is unaffected by nonsocial object salience. Time spent viewing social stimuli is associated with cognitive development and blood levels of oxytocin.

Eye-Tracking Studies in Adults with Autism Spectrum Disorder: A Systematic Review and Meta-analysis

Eye-tracking studies have shown potential in effectively discriminating between autism spectrum disorder (ASD) and non-ASD groups. The main objective of the present study was to conduct a systematic review and meta-analysis of eye-tracking studies in adults with ASD. A total of 22 studies were included for meta-analysis. Eyes and Non-Social regions proved better for discriminating between ASD and non-ASD adults, while fixation duration seems to be the outcome to choose. Active engaged tasks seem to reduce differences between ASD and non-ASD adults, regardless of the emotional content of the stimuli/task. Proportional fixation duration on eyes and non-social areas in non-active tasks (e.g. free viewing) seems to be the best eye-tracking design for increasing the sensitivity and specificity in ASD adults.

Unity Assumption in Audiovisual Emotion Perception

We experience various sensory stimuli every day. How does this integration occur? What are the inherent mechanisms in this integration? The “unity assumption” proposes a perceiver’s belief of unity in individual unisensory information to modulate the degree of multisensory integration. However, this has yet to be verified or quantified in the context of semantic emotion integration. In the present study, we investigate the ability of subjects to judge the intensities and degrees of similarity in faces and voices of two emotions (angry and happy). We found more similar stimulus intensities to be associated with stronger likelihoods of the face and voice being integrated. More interestingly, multisensory integration in emotion perception was observed to follow a Gaussian distribution as a function of the emotion intensity difference between the face and voice—the optimal cut-off at about 2.50 points difference on a 7-point Likert scale. This provides a quantitative estimation of the multisensory integration function in audio-visual semantic emotion perception with regards to stimulus intensity. Moreover, to investigate the variation of multisensory integration across the population, we examined the effects of personality and autistic traits of participants. Here, we found no correlation of autistic traits with unisensory processing in a nonclinical population. Our findings shed light on the current understanding of multisensory integration mechanisms.

Integration of Facial Expression and Gaze Direction in Individuals with a High Level of Autistic Traits

BACKGROUND

We investigated whether individuals with high levels of autistic traits integrate relevant communicative signals, such as facial expression, when decoding eye-gaze direction.

METHODS

Students with high vs. low scores on the Autism Spectrum Quotient (AQ) performed a task in which they responded to the eye directions of faces, presented on the left or the right side of a screen, portraying different emotional expressions.

RESULTS

In both groups, the identification of gaze direction was faster when the eyes were directed towards the center of the scene. However, in the low AQ group, this effect was larger for happy faces than for neutral faces or faces showing other emotional expressions, whereas participants from high AQ group were not affected by emotional expressions.

CONCLUSIONS

These results suggest that individuals with more autistic traits may not integrate multiple communicative signals based on their emotional value.

Multimodal Evidence of Atypical Processing of Eye Gaze and Facial Emotion in Children With Autistic Traits

According to the shared signal hypothesis (SSH) the impact of facial expressions on emotion processing partially depends on whether the gaze is directed toward or away from the observer. In autism spectrum disorder (ASD) several aspects of face processing have been found to be atypical, including attention to eye gaze and the identification of emotional expressions. However, there is little research on how gaze direction affects emotional expression processing in typically developing (TD) individuals and in those with ASD. This question is investigated here in two multimodal experiments. Experiment 1 required processing eye gaze direction while faces differed in emotional expression. Forty-seven children (aged 9-12 years) participated. Their Autism Diagnostic Observation Schedule (ADOS) scores ranged from 0 to 6 in the experiment. Event-related potentials (ERPs) were sensitive to gaze direction and emotion, but emotion processing did not depend on gaze direction. However, for angry faces the gaze direction effect on the N170 amplitude, as typically observed in TD individuals, diminished with increasing ADOS score. For neutral expressions this correlation was not significant. Experiment 2 required explicit emotion classifications in a facial emotion composite task while eye gaze was manipulated incidentally. A group of 22 children with ASD was compared to a propensity score-matched group of TD children (mean age = 13 years). The same comparison was carried out for a subgroup of nine children with ASD who were less trained in social cognition, according to clinician's report. The ASD group performed overall worse in emotion recognition than the TD group, independently of emotion or gaze direction. However, for disgust expressions, eye tracking data revealed that TD children fixated relatively longer on the eyes of the stimulus face with a direct gaze as compared with averted gaze. In children with ASD we observed no such modulation of fixation behavior as a function of gaze direction. Overall, the present findings from ERPs and eye tracking confirm the hypothesis of an impaired sensitivity to gaze direction in children with ASD or elevated autistic traits, at least for specific emotions. Therefore, we conclude that multimodal investigations of the interaction between emotional processing and stimulus gaze direction are promising to understand the characteristics of individuals differing along the autism trait dimension.

How to choose the size of facial areas of interest in interactive eye tracking

Advances in eye tracking technology have enabled the development of interactive experimental setups to study social attention. Since these setups differ substantially from the eye tracker manufacturer's test conditions, validation is essential with regard to the quality of gaze data and other factors potentially threatening the validity of this signal. In this study, we evaluated the impact of accuracy and areas of interest (AOIs) size on the classification of simulated gaze (fixation) data. We defined AOIs of different sizes using the Limited-Radius Voronoi-Tessellation (LRVT) method, and simulated gaze data for facial target points with varying accuracy. As hypothesized, we found that accuracy and AOI size had strong effects on gaze classification. In addition, these effects were not independent and differed in falsely classified gaze inside AOIs (Type I errors; false alarms) and falsely classified gaze outside the predefined AOIs (Type II errors; misses). Our results indicate that smaller AOIs generally minimize false classifications as long as accuracy is good enough. For studies with lower accuracy, Type II errors can still be compensated to some extent by using larger AOIs, but at the cost of more probable Type I errors. Proper estimation of accuracy is therefore essential for making informed decisions regarding the size of AOIs in eye tracking research.

What children with and without ASD see: Similar visual experiences with different pathways through parental attention strategies

Background and aims

Although young children's gaze behaviors in experimental task contexts have been shown to be potential biobehavioral markers relevant to autism spectrum disorder (ASD), we know little about their everyday gaze behaviors. The present study aims (1) to document early gaze behaviors that occur within a live, social interactive context among children with and without ASD and their parents, and (2) to examine how children's and parents' gaze behaviors are related for ASD and typically developing (TD) groups. A head-mounted eye-tracking system was used to record the frequency and duration of a set of gaze behaviors (such as sustained attention [SA] and joint attention [JA]) that are relevant to early cognitive and language development.

Methods

Twenty-six parent-child dyads (ASD group = 13, TD group = 13) participated. Children were between the ages of 3 and 8 years old. We placed head-mounted eye trackers on parents and children to record their parent- and child-centered views, and we also recorded their interactive parent-child object play scene from both a wall- and ceiling-mounted camera. We then annotated the frequency and duration of gaze behaviors (saccades, fixation, SA, and JA) for different regions of interest (object, face, and hands), and attention shifting. Independent group t-tests and ANOVAs were used to observe group comparisons, and linear regression was used to test the predictiveness of parent gaze behaviors for JA.

Results

The present study found no differences in visual experiences between children with and without ASD. Interestingly, however, significant group differences were found for parent gaze behaviors. Compared to parents of ASD children, parents of TD children focused on objects and shifted their attention between objects and their children's faces more. In contrast, parents of ASD children were more likely to shift their attention between their own hands and their children. JA experiences were also predicted differently, depending on the group: among parents of TD children, attention to objects predicted JA, but among parents of ASD children, attention to their children predicted JA.

Conclusion

Although no differences were found between gaze behaviors of autistic and TD children in this study, there were significant group differences in parents' looking behaviors. This suggests potentially differential pathways for the scaffolding effect of parental gaze for ASD children compared with TD children.

Implications

The present study revealed the impact of everyday life, social interactive context on early visual experiences, and point to potentially different pathways by which parental looking behaviors guide the looking behaviors of children with and without ASD. Identifying parental social input relevant to early attention development (e.g., JA) among autistic children has implications for mechanisms that could support socially mediated attention behaviors that have been documented to facilitate early cognitive and language development and implications for the development of parent-mediated interventions for young children with or at risk for ASD.Note: This paper uses a combination of person-first and identity-first language, an intentional decision aligning with comments put forth by Vivanti (Vivanti, 2020), recognizing the complexities of known and unknown preferences of those in the larger autism community.

Data-driven analysis of gaze patterns in face perception: Methodological and clinical contributions

Gaze patterns during face perception have been shown to relate to psychiatric symptoms. Standard analysis of gaze behavior includes calculating fixations within arbitrarily predetermined areas of interest. In contrast to this approach, we present an objective, data-driven method for the analysis of gaze patterns and their relation to diagnostic test scores. This method was applied to data acquired in an adult sample (N = 111) of psychiatry outpatients while they freely looked at images of human faces. Dimensional symptom scores of autism, attention deficit, and depression were collected. A linear regression model based on Principal Component Analysis coefficients computed for each participant was used to model symptom scores. We found that specific components of gaze patterns predicted autistic traits as well as depression symptoms. Gaze patterns shifted away from the eyes with increasing autism traits, a well-known effect. Additionally, the model revealed a lateralization component, with a reduction of the left visual field bias increasing with both autistic traits and depression symptoms independently. Taken together, our model provides a data-driven alternative for gaze data analysis, which can be applied to dimensionally-, rather than categorically-defined clinical subgroups within a variety of contexts. Methodological and clinical contribution of this approach are discussed.

Eye gaze as a biomarker in the recognition of autism spectrum disorder using virtual reality and machine learning: A proof of concept for diagnosis

The core symptoms of autism spectrum disorder (ASD) mainly relate to social communication and interactions. ASD assessment involves expert observations in neutral settings, which introduces limitations and biases related to lack of objectivity and does not capture performance in real-world settings. To overcome these limitations, advances in technologies (e.g., virtual reality) and sensors (e.g., eye-tracking tools) have been used to create realistic simulated environments and track eye movements, enriching assessments with more objective data than can be obtained via traditional measures. This study aimed to distinguish between autistic and typically developing children using visual attention behaviors through an eye-tracking paradigm in a virtual environment as a measure of attunement to and extraction of socially relevant information. The 55 children participated. Autistic children presented a higher number of frames, both overall and per scenario, and showed higher visual preferences for adults over children, as well as specific preferences for adults' rather than children's faces on which looked more at bodies. A set of multivariate supervised machine learning models were developed using recursive feature selection to recognize ASD based on extracted eye gaze features. The models achieved up to 86% accuracy (sensitivity = 91%) in recognizing autistic children. Our results should be taken as preliminary due to the relatively small sample size and the lack of an external replication dataset. However, to our knowledge, this constitutes a first proof of concept in the combined use of virtual reality, eye-tracking tools, and machine learning for ASD recognition. LAY SUMMARY: Core symptoms in children with ASD involve social communication and interaction. ASD assessment includes expert observations in neutral settings, which show limitations and biases related to lack of objectivity and do not capture performance in real settings. To overcome these limitations, this work aimed to distinguish between autistic and typically developing children in visual attention behaviors through an eye-tracking paradigm in a virtual environment as a measure of attunement to, and extraction of, socially relevant information.

Atypical gaze patterns to facial feature areas in autism spectrum disorders reveal age and culture effects: A meta-analysis of eye-tracking studies

Children and adults with autism spectrum disorder (ASD) often present with atypical gaze patterns to others' faces, a finding substantiated throughout the literature. Yet, a quantification of atypical gaze patterns to different facial regions (e.g., eyes versus mouth) in ASD remains controversial. Also few study has investigated how age and culture impacted the pattern of gaze abnormalities in ASD. This research therefore conducted a meta-analysis of eye-tracking studies to evaluate age and culture effect on atypical gaze patterns of face processing in ASD. A total of 75 articles (91 studies) and 4209 individuals (ASD: 2027; controls: 2182) across all age ranges (i.e., childhood through to adulthood) from both Eastern and Western cultures were included in this meta-analysis. Individuals with ASD yielded shorter fixation durations to the eyes than individuals without ASD. Group differences in the time spent fixating on the eyes were not modulated by age, but affected by culture. Effect size in the eastern culture was larger than that in the western culture. In contrast, group differences on time spent looking at the mouth were not significant, but changed with age and modulated by culture. Relative to the neurotypical controls, Western individuals with ASD spent more time looking at the mouth from school age, whereas Eastern individuals with ASD did not gaze longer on mouth until adulthood. These results add to the body of evidence supporting atypical gaze behaviors to eyes in ASD and provide new insights into a potential mouth compensation strategy that develops with age in ASD. LAY SUMMARY: Individuals with autism spectrum disorder (ASD) often show atypical gaze patterns when looking at others' faces compared to neurotypical individuals. This paper examines the role of age and culture on pattern of gaze abnormalities in individuals with ASD. Results show that reduction of gaze on eyes in ASD is stable across all ages and cultures, while increase of gaze on mouth emerges as individuals with ASD get older. The findings provide a developmental insight to the gaze patterns on the autism spectrum across culture.

Basic oculomotor function is similar in young children with ASD and typically developing controls

A variety of eye tracking studies have demonstrated that young children with ASD gaze at images and movies of social interactions differently than typically developing children. These findings have supported the hypothesis that gaze behavior differences are generated by a weaker preference for social stimuli in ASD children. The hypothesis assumes that gaze differences are not caused by abnormalities in oculomotor function including saccade frequency and kinematics. Previous studies of oculomotor function have mostly been performed with school-age children, adolescents, and adults using visual search, anti-saccade, and gap saccade tasks that are less suitable for young pre-school children. Here, we examined oculomotor function in 144 children (90 with ASD and 54 controls), 1-10-years-old, as they watched two animated movies interleaved with the presentation of multiple salient stimuli that elicited saccades-to-targets. The results revealed that the number of fixations, fixation duration, number of saccades, saccade duration, saccade accuracy, and saccade latency did not differ significantly across groups. Minor initial differences in saccade peak velocity were not supported by analysis with a linear mixed model. These findings suggest that most children with ASD exhibit similar oculomotor function to that of controls, when performing saccades-to-targets or freely viewing child-friendly movies. This suggests that previously reported gaze abnormalities in children with ASD are not due to underlying oculomotor deficiencies. LAY SUMMARY: This study demonstrates that children with ASD perform similar eye movements to those of controls when freely observing movies or making eye movements to targets. Similar results were apparent across groups in the number of eye movements, their accuracy, duration, and other measures that assess eye movement control. These findings are important for interpreting previously reported differences in gaze behavior of children with ASD, which are likely due to atypical social preferences rather than impaired control of eye movements.

Visual preference for social vs. non-social images in young children with autism spectrum disorders. An eye tracking study

Autism Spectrum Disorders (ASD) are associated to social attention (SA) impairments. A gaze bias to non-social objects over faces has been proposed as an early marker of ASD. This bias may be related to the concomitant circumscribed interests (CI), which question the role of competing objects in this atypical visual behavior. The aim of this study was to compare visual attention patterns to social and non-social images in young children with ASD and matched typical controls (N = 36; age range 41-73 months) assessing the role of emotion in facial stimuli and the type of competing object. A paired preference task was designed pairing happy, angry, and neutral faces with two types of objects (related or not related to autism CI). Eye tracking data were collected, and three indexes were considered as dependent variables: prioritization (attentional orientation), preference, and duration (sustained attention). Results showed that both groups had similar visual pattern to faces (prioritization, more attention and longer visits to faces paired with objects non-related to their CI); however, the ASD group attended to faces significantly less than controls. Children with ASD showed an emotional bias (late orientation to angry faces and typical preference for happy faces). Finally, objects related to their CI captured attention in both groups, significantly reducing SA in children with ASD. Atypical SA is present in young children with ASD regardless the competing non-social object. Identifying strengths and difficulties in SA in this population may have substantial repercussion for early diagnosis, intervention, and ultimately prognosis.

Social attention as a cross-cultural transdiagnostic neurodevelopmental risk marker

The primary objectives of this study were to evaluate the structure and age-related stability of social attention in English and Arabic-speaking youth and to compare social attention between children with autism spectrum disorder (ASD), other developmental disabilities (DD), and typically-developing controls. Eye-tracking data were collected from US (N = 270) and Qatari (N = 242) youth ages 1-17, including children evaluated for possible ASD. Participants viewed 44 stimuli from seven social paradigms. Fixation was computed for areas of interest within each stimulus. Latent variable models examined the structure of social attention. Generalized estimating equation models examined the effect of age, sex, culture, and diagnostic group on social attention. The best-fitting model included a general social attention factor and six specific factors. Cultural differences in social attention were minimal and social attention was stable across age (r = 0.03), but females showed significantly greater social attention than males (d = 0.28). Social attention was weaker in DD (d = -0.17) and lowest in ASD (d = -0.38) relative to controls. Differences were of sufficient magnitude across areas-of-interest to reliably differentiate DD from controls (AUC = 0.80) and ASD-only from all other cases (AUC = 0.76). A social attention dimension that represents an early-life preference for socially salient information was identified. This preference was cross-culturally consistent and stable across development but stronger in females and weaker in DD, especially ASD. Given rapid and easy-to-collect remote eye tracking administration, social attention measurement may be useful for developmental monitoring. Acquisition of population norms, analogous to height/weight/head circumference, might enhance early screening and tracking of neurodevelopment. LAY SUMMARY: This research found that social attention is a single dimension of behavior that represents a strong preference for social stimuli, is consistent across cultures, stable across age, and stronger in females. Children with developmental disabilities had lower levels of social attention than neurotypical children and children with autism spectrum disorder had the lowest levels of social attention.

Effect of Cognitive Control on Attentional Processing of Emotional Information Among Older Adults: Evidence From an Eye-Tracking Study

Background: Although numerous studies have suggested that the gradually increasing selective preference for positive information over negative information in older adults depends on cognitive control processes, few have reported the characteristics of different attention stages in the emotional processing of older individuals. The present study used a real-time eye-tracking technique to disentangle the attentional engagement and disengagement processes involved in age-related positivity effect (PE). Methods: Eye movement data from a spatial-cueing task were obtained for 32 older and 32 younger healthy participants. The spatial-cueing task with varied cognitive loads appeared to be an effective way to explore the role of cognitive control during the attention engagement and disengagement stages of emotion processing. Results: Compared with younger adults, older participants showed more positive gaze preferences when cognitive resources were sufficient for face processing at the attention engagement stage. However, the age-related PE was not observed at the attention disengagement stage because older adults had more difficulty disengaging from fearful faces than did the younger adults due to the consumption of attention by the explicit target judgment. Conclusion: The present study highlights how cognitive control moderates positive gaze preferences at different attention processing stages. These findings may have far-reaching implications for understanding, preventing, and intervening in unsuccessful aging and, thus, in promoting active and healthy aging.

Using head-mounted eye tracking to examine visual and manual exploration during naturalistic toy play in children with and without autism spectrum disorder

Multimodal exploration of objects during toy play is important for a child's development and is suggested to be abnormal in children with autism spectrum disorder (ASD) due to either atypical attention or atypical action. However, little is known about how children with ASD coordinate their visual attention and manual actions during toy play. The current study aims to understand if and in what ways children with ASD generate exploratory behaviors to toys in natural, unconstrained contexts by utilizing head-mounted eye tracking to quantify moment-by-moment attention. We found no differences in how 24- to 48-mo children with and without ASD distribute their visual attention, generate manual action, or coordinate their visual and manual behaviors during toy play with a parent. Our findings suggest an intact ability and willingness of children with ASD to explore toys and suggest that context is important when studying child behavior.

Evaluation of an eye tracking setup for studying visual attention in face-to-face conversations

Many eye tracking studies use facial stimuli presented on a display to investigate attentional processing of social stimuli. To introduce a more realistic approach that allows interaction between two real people, we evaluated a new eye tracking setup in three independent studies in terms of data quality, short-term reliability and feasibility. Study 1 measured the robustness, precision and accuracy for calibration stimuli compared to a classical display-based setup. Study 2 used the identical measures with an independent study sample to compare the data quality for a photograph of a face (2D) and the face of the real person (3D). Study 3 evaluated data quality over the course of a real face-to-face conversation and examined the gaze behavior on the facial features of the conversation partner. Study 1 provides evidence that quality indices for the scene-based setup were comparable to those of a classical display-based setup. Average accuracy was better than 0.4° visual angle. Study 2 demonstrates that eye tracking quality is sufficient for 3D stimuli and robust against short interruptions without re-calibration. Study 3 confirms the long-term stability of tracking accuracy during a face-to-face interaction and demonstrates typical gaze patterns for facial features. Thus, the eye tracking setup presented here seems feasible for studying gaze behavior in dyadic face-to-face interactions. Eye tracking data obtained with this setup achieves an accuracy that is sufficient for investigating behavior such as eye contact in social interactions in a range of populations including clinical conditions, such as autism spectrum and social phobia.

Diagnosing Autism Spectrum Disorder Without Expertise: A Pilot Study of 5- to 17-Year-Old Individuals Using Gazefinder

Atypical eye gaze is an established clinical sign in the diagnosis of autism spectrum disorder (ASD). We propose a computerized diagnostic algorithm for ASD, applicable to children and adolescents aged between 5 and 17 years using Gazefinder, a system where a set of devices to capture eye gaze patterns and stimulus movie clips are equipped in a personal computer with a monitor. We enrolled 222 individuals aged 5–17 years at seven research facilities in Japan. Among them, we extracted 39 individuals with ASD without any comorbid neurodevelopmental abnormalities (ASD group), 102 typically developing individuals (TD group), and an independent sample of 24 individuals (the second control group). All participants underwent psychoneurological and diagnostic assessments, including the Autism Diagnostic Observation Schedule, second edition, and an examination with Gazefinder (2 min). To enhance the predictive validity, a best-fit diagnostic algorithm of computationally selected attributes originally extracted from Gazefinder was proposed. The inputs were classified automatically into either ASD or TD groups, based on the attribute values. We cross-validated the algorithm using the leave-one-out method in the ASD and TD groups and tested the predictability in the second control group. The best-fit algorithm showed an area under curve (AUC) of 0.84, and the sensitivity, specificity, and accuracy were 74, 80, and 78%, respectively. The AUC for the cross-validation was 0.74 and that for validation in the second control group was 0.91. We confirmed that the diagnostic performance of the best-fit algorithm is comparable to the diagnostic assessment tools for ASD.

Social Attention Deficits in Children With Autism Spectrum Disorder: Task Dependence of Objects vs. Faces Observation Bias

Social attention deficits represent a central impairment of patients suffering from autism spectrum disorder (ASD), but the nature of such deficits remains controversial. We compared visual attention regarding social (faces) vs. non-social stimuli (objects), in an ecological diagnostic context, in 46 children and adolescents divided in two groups: ASD (N = 23) and typical neurodevelopment (TD) (N = 23), matched for chronological age and intellectual performance. Eye-tracking measures of visual scanning, while exploring and describing scenes from three different tasks from the Autism Diagnostic Observation Schedule (ADOS), were analyzed: "Description of a Picture," "Cartoons," and "Telling a Story from a Book." Our analyses revealed a three-way interaction between Group, Task, and Social vs. Object Stimuli. We found a striking main effect of group and a task dependence of attentional allocation: while the TD attended first and longer to faces, ASD participants became similar to TD when they were asked to look at pictures while telling a story. Our results suggest that social attention allocation is task dependent, raising the question whether spontaneous attention deficits can be rescued by guiding goal-directed actions.

Social orienting and social seeking behaviors in ASD. A meta analytic investigation

Social motivation accounts of autism spectrum disorder (ASD) posit that individuals with ASD find social stimuli less rewarding than neurotypical (NT) individuals. Behaviorally, this is proposed to manifest in reduced social orienting (individuals with ASD direct less attention towards social stimuli) and reduced social seeking (individuals with ASD invest less effort to receive social stimuli). In two meta-analyses, involving data from over 6000 participants, we review the available behavioral studies that assess social orienting and social seeking behaviors in ASD. We found robust evidence for reduced social orienting in ASD, across a range of paradigms, demographic variables and stimulus contexts. The most robust predictor of this effect was interactive content - effects were larger when the stimulus involved an interaction between people. By contrast, the evidence for reduced social seeking indicated weaker evidence for group differences, observed only under specific experimental conditions. The insights gained from this meta-analysis can inform design of relevant task measures for social reward responsivity and promote directions for further study on the ASD phenotype.

Best practices in eye tracking research

This guide describes best practices in using eye tracking technology for research in a variety of disciplines. A basic outline of the anatomy and physiology of the eyes and of eye movements is provided, along with a description of the sorts of research questions eye tracking can address. We then explain how eye tracking technology works and what sorts of data it generates, and provide guidance on how to select and use an eye tracker as well as selecting appropriate eye tracking measures. Challenges to the validity of eye tracking studies are described, along with recommendations for overcoming these challenges. We then outline correct reporting standards for eye tracking studies.