Comparative eye-tracking analysis of visual behavior of normal developing and autistic children in response to human faces and emotional expressions

Previous research links resting frontal gamma power to key developmental outcomes in young neurotypical (NT) children and infants at risk for language impairment. However, it remains unclear whether gamma power is specifically associated with language or with more general cognitive abilities among young children diagnosedwith autism spectrum disorder (ASD). The current study evaluates differences in resting frontal gamma power between young autistic and NT children and tests whether gamma power is uniquely associated with individual differences in expressive language, receptive language and non-verbal cognitive abilities in autistic and NT children. Participants included 48 autistic children and 58 age- and sex-matched NT children (ages 22-60months). Baseline electroencephalography (EEG) recordings were acquired from each participant. Children also completed the Mullen Scales of Early Learning (MSEL). We found thatfrontal gamma power at rest did not differ between autistic and NT children. Among autistic children, reduced frontal gamma power was significantly associated with both higher expressive language skills and higher non-verbal cognitive skills, controlling for age and sex. The interaction between frontal gamma power and diagnostic status no longer explained unique variance in expressive language skills after controlling for variance associated with non-verbal cognitive skills across autistic and NT children. Together, these findings suggest that reduced gamma power is associated with both better expressive language and non-verbal cognitive skills among young autistic children. Moreover, associations between high frequency neural activity and cognition are not specific to verbal abilities but reflect neural mechanisms associated with general higher-order cognitive abilities in ASD.

Recent theories propose that domain-general deficits in prediction (i.e., the ability to anticipate upcoming information) underlie the behavioral characteristics associated with autism spectrum disorder (ASD). If these theories are correct, autistic children might be expected to demonstrate difficulties on linguistic tasks that rely on predictive processing. Previous research has largely focused on older autistic children and adolescents with average language and cognition. The present study used an eye-gaze task to evaluate predictive language processing among 3- to 4-year-old autistic children (n= 34) and 1.5- to 3-year-old, language-matched neurotypical (NT) children (n= 34). Children viewed images (e.g., a cake and a ball) and heard sentences with informative verbs (e.g., Eat the cake) or neutral verbs (e.g., Find the cake). Analyses of children's looking behaviors indicated that young autistic children, like their language-matched NT peers, engaged in predictive language processing. Regression results revealed a significant effect of diagnostic group, when statistically controlling for age differences. The NT group displayed larger difference scores between the informative and neutral verb conditions (in looks to target nouns) compared to the ASD group. Receptive language measures were predictive of looking behavior across time for both groups, such that children with stronger language skills were more efficient in making use of informative verbs to process upcoming information. Taken together, these results suggest that young autistic children can engage in predictive processing though further research is warranted to explore the developmental trajectory relative to NT development. LAY SUMMARY: This study found that 3- to 4-year-old autistic children and younger, language-matched neurotypical (NT) children both used verbs to predict upcoming nouns in sentences like "Eat the cake." For both autistic and NT children, those with stronger language skills were able to predict upcoming nouns more quickly.

Exposure to multiple languages may support the development of Theory of Mind (ToM) in neurotypical (NT) and autistic children. However, previous research mainly applied group comparisons between monolingual and bilingual children, and the underlying mechanism of the observed difference remains unclear. The present study, therefore, sheds light on the effect of bilingualism on ToM in both NT and autistic children by measuring language experiences with a continuous operationalization. We measure ToM with a behavioral, linguistically simple tablet-based task, allowing inclusive assessment in autistic children. Analyses revealed no difference between monolingual and bilingual NT and autistic children. However, more balanced exposure to different languages within contexts positively predicted first-order false belief understanding in NT children but not autistic children. Mediation analysis showed that the impact in NT children was a direct effect and not mediated via other cognitive skills.

Keeping a conversation going is the social glue of friendships. The DSM criteria for autism list difficulties with back-and-forth conversation but does not necessitate that all autistic children will be equally impacted. We carried out three studies (two pre-registered) with verbally fluent school children (age 5-9 years) to investigate how autistic and neurotypical children maintain a conversation topic. We also investigated within-group relationships between conversational ability and cognitive and sociocognitive predictors. Study 1 found autistic children were more likely than neurotypical controls to give off-topic and generic minimal responses (e.g. 'mm', 'oh') and were less likely to give non-verbal responses (e.g. nodding or use of facial affect to respond). Nonetheless, the autistic group provided topic-supporting responses 62% of the time, indicating some aspects of conversation topic maintenance are a relative strength. Studies 2 and 3 found large individual differences in topic-supporting conversational responding among both neurotypical and autistic children. These were positively related to theory of mind ability and age in both groups. Conversational skills lie on a continuum for the general population and differences by diagnostic group are a matter of degree. Given the importance for peer relationships, we suggest a whole classroom approach to supporting conversation skills in all children.Lay abstractChildren who struggle to maintain conversation with peers often have fewer friends and lower popularity ratings, which can affect wellbeing. Verbal social communication more broadly is linked to both behavioural difficulties and emotional problems. We carried out three studies to examine children's ability to provide responses which keep a back and forth conversation going. The first study found that while autistic children had on average greater difficulties than their neurotypical peers with certain aspects of conversation topic maintenance, for other aspects the autistic group showed considerable strengths. Both studies 2 (neurotypical children) and 3 (autistic children) found relationships between, on the one hand, conversational ability, and on the other, the ability to consider another's viewpoint and the ability to maintain and update information in short term memory. We suggest support for social conversation skills should be part of mainstream classroom curricula for autistic and neurotypical children alike.

BackgroundGaze following difficulties are considered an early marker of autism, thought likely to cumulatively impact the development of social cognition, language and social skills. Subtle differences in gaze following abilities may contribute to the diverse range social and communicative autistic characteristics observed across people with genetic syndromes, such as Cornelia de Lange (CdLS) and fragile X (FXS) syndromes. AimsTo compare profiles of 1) visual attention to the eye region at critical points of the attention direction process, 2) whether children follow the gaze cue to the object, and 3) participant looking time to the target object following the gaze cue between groups and conditions. Materials and methodsChildren with CdLS (N = 11) and FXS (N = 8) and autistic (N = 22) and neurotypical (N = 15) children took part in a passive viewing paradigm adapted from Senju and Csibra (2008), in which videos of a central cue (ball/cartoon face/human face) directed attention towards one of two objects. Visual attention patterns were recorded via eye tracking technology. ResultsNeurotypical children were used as a reference group against which the autistic, CdLS and FXS groups were compared. Although autistic children looked at the eye region for significantly less time, they looked at the target object as frequently and for a similar duration as neurotypical children. Children with FXS looked at the target as frequently as neurotypical children but looked at it for comparatively less time. Both neurotypical children and children with CdLS frequently looked at the eye region, but children with CdLS were less likely to look at the target than neurotypical children. ConclusionsFindings provide preliminary evidence of unique patterns of visual attention and gaze following strategies in children with CdLS, children with FXS and autistic children. These unique gaze following patterns may underpin the distinct profiles of social and communication autistic traits observed between these groups.

BackgroundLittle is known about how autistic children’s brains process language during real-world “social contexts,” despite the fact that challenges with language, communication, and social interaction are core features of Autism Spectrum Disorder (ASD).MethodsWe investigated the neural bases of language processing during social and non-social contexts in a sample of autistic and neurotypical (NT) preschool-aged children, 3–6 years old, living in the United States. Functional near-infrared spectroscopy was used to measure children’s brain response to “live language” spoken by a live experimenter during an in-person social context (i.e., book reading) and “recorded language” played via an audio recording during a non-social context (i.e., screen time). We examined within-group and between-group differences in the strength and localization of brain response to live language and recorded language, as well as correlations between children’s brain response to live language versus recorded language and their language skills, as measured by the Preschool Language Scales.ResultsIn the NT group, brain response to live language was greater than brain response to recorded language in the right temporal parietal junction (TPJ). In the ASD group, the strength of brain response did not differ between conditions in any brain regions of interest after correction for multiple comparisons. Children who showed a greater difference in right TPJ brain response to live language versus recorded language had higher language skills; this significant correlation was driven by the ASD group.LimitationsFindings should be considered preliminary until they are replicated in a larger sample.ConclusionsGroup level findings indicate that for NT children, but not autistic children, the right TPJ responds more strongly to live language presented during a social context compared to recorded language presented during a non-social context. However, individual differences in how the right TPJ responds to language during social versus non-social contexts may help to explain why language skills are so variable across children on the autism spectrum.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13229-025-00655-3.

BackgroundUnusual behavioral reactions to sensory stimuli are frequently reported in individuals on the autism spectrum (AS). Despite the early emergence of sensory features (< age 3) and their potential impact on development and quality of life, little is known about the neural mechanisms underlying sensory reactivity in early childhood autism.MethodsHere, we used electroencephalography (EEG) to investigate tactile cortical processing in young children aged 3–6 years with autism and in neurotypical (NT) children. Scalp EEG was recorded from 33 children with autism, including those with low cognitive and/or verbal abilities, and 45 age- and sex-matched NT children during passive tactile fingertip stimulation. We compared properties of early and later somatosensory-evoked potentials (SEPs) and their adaptation with repetitive stimulation between autistic and NT children and assessed whether these neural measures are linked to “real-world” parent-reported tactile reactivity.ResultsAs expected, we found elevated tactile reactivity in children on the autism spectrum. Our findings indicated no differences in amplitude or latency of early and mid-latency somatosensory-evoked potentials (P50, N80, P100), nor adaptation between autistic and NT children. However, latency of later processing of tactile information (N140) was shorter in young children with autism compared to NT children, suggesting faster processing speed in young autistic children. Further, correlational analyses and exploratory analyses using tactile reactivity as a grouping variable found that enhanced early neural responses were associated with greater tactile reactivity in autism.LimitationsThe relatively small sample size and the inclusion of a broad range of autistic children (e.g., with low cognitive and/or verbal abilities) may have limited our power to detect subtle group differences and associations. Hence, replications are needed to verify these results.ConclusionsOur findings suggest that electrophysiological somatosensory cortex processing measures may be indices of “real-world” tactile reactivity in early childhood autism. Together, these findings advance our understanding of the neurophysiological mechanisms underlying tactile reactivity in early childhood autism and, in the clinical context, may have therapeutic implications.

"Hot" or reward-based executive function describes the regulatory skills needed to suppress or delay actions in emotionally salient contexts. These delay-based executive function skills impact social development, mental health, and academic achievement. Accumulating evidence indicates that autistic children (3 years or older) show reduced delay-based executive function relative to neurotypical counterparts. The primary aim of this study was to determine whether these findings extend to younger children (younger than 3 years). Our secondary aim was to determine whether the strategies employed during delay-based executive function tasks differed between autistic and neurotypical toddlers, to understand why autistic children often experience difficulty in this domain. A behavioral battery was administered to measure delay-based executive function in autistic and neurotypical children, aged 2 and 4 years. Consistent with evidence in older children, delay-based executive function was reduced in autistic toddlers. Autistic 2-year-olds waited less during tasks that utilized food rewards, whereas autistic 4-year-olds waited less during tasks using both food- and non-food-based incentives. Autistic children also used significantly less adaptive strategies during tasks. These results are the first to indicate diagnostic differences in delay-based executive function among children as young as 2 years and may inform interventions that target these skills to improve related developmental outcomes.Lay Abstract"Hot" executive function involves the ability to control actions when emotions are involved. For example, a situation when an individual must resist a temptation requires hot executive function. These skills are important for social growth, mental health, and doing well in school. Research shows that autistic children over 3 years of age are less likely to use these skills compared to other children. This study examined whether autistic children under 3 years of age show similar difficulties. We also examined whether autistic children use different strategies than neurotypical children. To find out, we asked both autistic and neurotypical children, ages 2 and 4 years, to complete tasks that required them to delay their responses. The study found that, like older autistic children, younger autistic children also delayed their responses less than neurotypical children. Autistic 2-year-olds waited less for rewards, like food, compared to their neurotypical peers. Similarly, autistic 4-year-olds waited less for both food and other types of rewards, compared to their neurotypical peers. Relative to their neurotypical peers, autistic children also used fewer effective strategies during these tasks. These findings suggest that even very young autistic children have differences in impulse control, which might help in creating better support and interventions for them.

Successful word learning requires children to pay attention to corresponding auditory and visual input during naming events. However, differences in autistic children's visual attention that restrict their intake of information may impact encoding of novel word-referent associations in memory. This study investigated differences in autistic and neurotypical children's visual attention to stimuli, and whether these differences predicted referent selection and retention accuracy. Fifteen autistic (Mage = 91.87 months) and sixteen neurotypical (Mage = 52.31 months) children matched on receptive vocabulary (Mage autistic children = 53.27 months; Mage neurotypical children = 60.31) used a touch-screen computer to fast map novel words associated with animals (high-interest stimuli) and objects (neutral-interest stimuli). Retention was assessed after 5minutes and 24hours. Children's frequency and duration of looking towards targets was recorded directly via multiple cameras. Neurotypical children spent longer looking at targets during referent selection than autistic children. Autistic children looked at targets significantly more frequently than neurotypical children across word learning stages, and more frequently at targets in the animal condition at 5-minute retention. In-trial visual attention predicted response accuracy across word learning stages for both groups. Visual attention at referent selection also predicted 5-minute and 24-hour retention accuracy for both groups. Visual input during initial encoding influences children's likelihood of successfully forming long-term word-referent representations, indicating strong relationships between attention and learning accuracy. Moreover, population differences in visual attention may not have a detrimental impact on autistic children's word learning under experimental conditions when expectations are based on receptive vocabulary.

Breastfeeding is a complex task that requires proficiency at several key developmental skills to feed successfully. It is unclear how Autism Spectrum Disorder (ASD) affects an infant's breastfeeding experience and conflicting reports exist on shortened breastfeeding duration in infants later diagnosed with ASD. The purpose of this study was to describe the experiences of mothers breastfeeding both their autistic and neurotypical children to better understand the differences in their breastfeeding experiences and maternal and infant factors that contributed to breastfeeding cessation in their autistic child. Twenty-four mothers of an autistic child who had feeding difficulties in the first 12 months of life, initiated breastfeeding, and also had a neurotypical child participated in semi-structured interviews regarding breastfeeding initiation, cessation, and challenges encountered during breastfeeding. Analysis revealed four major themes: (1) the struggle with latch, including infant behavior that hindered latching; (2) breastfeeding challenges, including problematic breastfeeding behavior by the infant; (3) cessation of breastfeeding, including physical symptoms of the infant that lead to breastfeeding cessation; and (4) breastfeeding the neurotypical sibling, including mother's detection of different breastfeeding behaviors in neurotypical and autistic child. Breastfeeding behaviors described by mothers may indicate early signs of autism including early sensory sensitivity, lack of regulation, repetitive behaviors, and impaired social behaviors. Further research is needed to discern if these breastfeeding behaviors can be used to help identify early signs of autism and employed as additional surveillance for neurodevelopmental concerns at a young age.

It has been suggested that mentalizing abilities underlie the distinct profiles of autism characteristics observed between Cornelia de Lange (CdLS) and fragile X syndromes (FXS) and autistic people without a genetic syndrome. However, traditional explicit mentalizing tasks have high language demands that may mask true mentalizing abilities in these populations. We compared performance on traditional explicit tasks and an implicit anticipatory looking mentalizing task in children with CdLS (N = 9), boys with FXS (N = 9), autistic (N = 22) and neurotypical (N = 34) children. The groups showed divergent patterns of performance. Neurotypical children had higher explicit mentalizing scores than all other groups. However, neurotypical, FXS and CdLS groups showed better implicit mentalizing performance than autistic children. Both chronological age and receptive language ability correlated with explicit mentalizing scores in neurotypical children. In autistic children, there was an association between explicit mentalizing score and receptive language ability but not chronological age. Explicit mentalizing score was not associated with receptive language ability or chronological age in the CdLS and FXS groups. Neither chronological age nor receptive language ability correlated with implicit mentalizing task performance in any group. Findings suggest that explicit tasks may mask true mentalizing abilities in autistic children, children with CdLS and children with FXS.

Autistic children (AT) are known to exhibit distinct postural control patterns compared to neurotypical (NT) children. However, identifying and interpreting these differences can be complex due to the wide range of variables used to analyse Centre of Pressure (CoP) trajectories. This study aims to elucidate the specific characteristics of postural control in AT children by identifying the most discriminative CoP variables that distinguish them from NT children. The study evaluated 24 AT and 24 NT children while they stood on a force plate for 30s under three conditions: eyes open (EO), eyes closed (EC), and the feet on a foam pad with eyes open (EOF). A total of 75 variables-including frequential, linear, and non-linear variables-were extracted from the CoP trajectory. These variables, expressed as the rate of change between the EC and EOF conditions relative to the EO condition, were compared between the AT and NT groups. A best-subsets approach was used to identify the most discriminative variables, and Pearson correlations were calculated to assess their relationship with age and Social Responsiveness Scale (SRS) scores. Of the 75 variables analysed, 15 showed significant differences between the AT and NT groups. The best-subsets analysis and the correlations revealed that variables such as the rate of change between the EOF and EO conditions, and the root mean square of the trembling component of the CoP trajectory, were particularly discriminative. Autistic children demonstrated a more rigid and regular CoP trajectory, particularly in the EO condition, compared to NT children. These findings suggest that AT children have greater difficulty integrating multisensory information and an increased reliance on supraspinal processes for postural control.

This study investigated the activation of thematic and taxonomic relations during online lexical-semantic processing in autistic children using an eye-tracking competition task. Thirty-six preschool-aged autistic children and 35 age-, gender-, and verbal-IQ-matched neurotypical (NT) children viewed arrays containing a target object, a thematically related competitor, a taxonomically related competitor, and an unrelated distractor while hearing the target word. Results revealed three key findings. First, both groups demonstrated activation of thematic and taxonomic relations during lexical processing, with comparable timing of activation onset. Second, while autistic children began to systematically orient attention to the target as quickly as NT children, they showed reduced overall attention to the target during lexical processing. Third, autistic children exhibited stronger activation of taxonomic relations and stronger taxonomic competition effects on target recognition compared to NT children, whereas their activation of thematic relations and thematic competition effects were comparable to NT children. These findings suggest that while the basic thematic and taxonomic activation processes remain robust in autistic children, and while their initial activation of the target and semantically related representations is as fast as that of NT children, the increased sensitivity to taxonomic relations in autistic children might interfere with the overall processing efficiency of target words. These results advance our understanding of lexical-semantic organization and processing in autism and provide implications for language intervention strategies.

This study addresses the research gap concerning whether the use of fidget toys or fidget spinners specifically are perceived to support children and positively influence their behavioural and emotional wellbeing as well as investigating how these perceptions relate to children’s sensory-seeking profiles. 129 parents/carers of autistic children (n = 53) and neurotypical (NT) children (n = 76) completed an online survey. The survey consisted of questions relating to the benefits and risks of fidget toys as well as statements about their own child’s fidget toy use. The Sensory Profile 2 was used to obtain parents perspectives on their child’s sensory behaviours. The main findings demonstrated that parents of autistic children perceived fidget toys and fidget spinners to be overall more beneficial than NT parents, especially in relation to reducing anxiety. Higher sensory-seeking scores for both autistic children and NT children were associated with greater parental agreement for fidget toys and fidget spinners being beneficial. Parents of autistic children with higher sensory seeking scores found fidget toys to reduce anxiety and spinners to be less distracting. Whereas, parents of NT children with higher sensory seeking scores perceived both fidget toys and spinners to help their child concentrate. Implications include that educators should consider parental views when forming policies about the use of fidget toys. Findings also imply that the sensory profiles of autistic and NT students should be considered in relation to the use of fidget toys.

This study introduces a novel linguistically simple, tablet-based, behavioral Theory of Mind (ToM) measure, designed for neurotypical (NT) and autistic children aged 4–10 years. A synthesis of five comprehensive reviews of existing ToM measures revealed significant gaps in their designs; the weaknesses include a mismatch between the operational and conceptual definition of ToM, high verbal demands in most measures, materials that are minimally interesting for children, and often a lack of psychometric evaluations. These findings call into question the suitability of most of the currently available ToM measures used in children, both with and without developmental disorders, such as children with autism spectrum disorder (ASD). For example, the assessment of ToM in children with ASD may require reduced reliance on complex language or social interaction that can be part of the diagnostic criteria of the condition. This newly designed ToM measure, developed in line with the “Standards for Educational and Psychological Testing” of the American Educational Research Association, is linguistically simple, tablet-based, suitable for children with ASD, and is available in English, German, French, Italian, and Spanish. With a sample of 234 participants, including 152 NT children and 82 children with ASD between 4 and 10 years of age, the new ToM measure's psychometric properties were preliminarily evaluated. Descriptive statistics, measures of internal consistency, inter-item correlation, and validity checks were conducted in both groups. Further inspections of the measure's scale- and item-level characteristics were conducted with the help of exploratory factor analyses (EFA), and item response theory (IRT) within the NT children's group. These preliminary evaluations suggest that the newly developed ToM measure possesses good psychometric properties and is both accessible and engaging for children. Further investigation with a larger group of participants is necessary to reinforce these initial results. This will allow item- and scale-level assessments within a wider range of autistic children. For this purpose, the task will be made freely available to the scientific community.