Identifying phenotypic and physiological subgroups of preschoolers with autism spectrum disorder.

BACKGROUND: To understand the emergence of symptoms in autism spectrum disorder (ASD), we need to identify the mechanisms that underpin the development of core social skills. Mounting evidence indicates that young children with later ASD attend less to other people, which could compromise learning opportunities with cascading effects. Passive looking behaviour does not tell us about engagement with visual information, but measures of physiological arousal can provide information on the depth of engagement. In the current study, we use heart rate (HR) and heart rate variability (HRV) to measure engagement with social dynamic stimuli in ASD. METHODS: Sixty-seven preschoolers with ASD and 65 typical developing preschoolers between 2 and 4 years of age participated in a study where HR was measured during viewing of social and non-social videos. Using latent profile analyses, more homogeneous subgroups of children were created based on phenotype and physiology. RESULTS: Preschool-aged children with ASD, regardless of their non-verbal, verbal and social competencies, do not differ in overall HR or HRV compared to TD children. However, the ASD group showed a larger increase in HR (more disengagement) than the TD group to later-presented social stimuli. Phenotypic and physiological profiles showed this was primarily the case for children with below average verbal and non-verbal skills, but not necessarily those with more ASD symptoms. CONCLUSION: Children with ASD, especially a subgroup showing moderate cognitive delays, show an increase in HR to social stimuli over time; this may reflect difficulties re-engaging with social information when attention is waning.

Mobile Media Content Exposure and Toddlers' Responses to Attention Prompts and Behavioral Requests.

Importance: With personalized touch-screen tablets, young children can choose content and engage in play-like activities. However, tablets may also reduce shared engagement as the action of viewing or touching the screen is often not visible to nearby adults. This may impact communicative gazing and pointing, which is critical to the formation of shared awareness and in turn supports language development. Objective: To assess the association of tablet media content with toddlers' responses to joint attention prompts and behavioral requests. Design, Setting, and Participants: This cohort study took place at a behavioral research laboratory and included toddlers who were aged 18 to 32 months with neurotypical development who were recruited from a volunteer and community sample. Toddlers engaged with a real toy or 3 different types of tablet content (ie, viewing video of toy play, playing with a digital toy, or playing a commercial game) while an experimenter delivered joint attention prompts. Data were acquired from June 2021 November XX 2022, and data analysis occurred from January 2023 to May 2024. Main Outcomes and Measures: Main outcomes included child response to joint attention (number of prompts with joint attention response per number of prompts delivered) and child response to behavioral request (ie, the prompt on which the child responded to the behavioral request). Measures included crossed random effects, Wald tests, and likelihood ratio tests. Results: In this study, 63 toddlers were enrolled, and data from 62 were included (31 female [49%]; mean [SD] age, 26.1 [3.4] months; median [IQR] age, 25.0 [18.6-32.6] months). When toddlers were playing a commercial game on a tablet, they responded to fewer joint attention prompts (crossed random effects model, -0.15; 95% CI, -0.24 to -0.06 prompts) and male toddlers took longer to acknowledge a behavioral request (interaction of content and sex, -0.75; 95% CI, -1.36 to -0.17). The negative impact of the tablet game was larger as child age increased (τ = -2.30; 95% CI, -0.05 to 0; P = .03). Greater media use at home was associated with decreased responding to joint attention prompts during the tablet game (ρ = -0.47; P < .001), while better language skills were associated with more joint attention during play with a real toy (ρ = 0.31; P = .02). Conclusions and Relevance: In this cohort study, a touch-screen tablet game was associated with decreased joint attention among toddlers and they were less likely to respond to a behavioral request. In a laboratory setting, it was difficult for toddlers to engage in social-communicative interactions with adults when using a tablet media device.

Language and Aggressive Behaviors in Male and Female Youth with Autism Spectrum Disorder.

Aggressive behaviors are common among youth with autism spectrum disorder (ASD) and correlate with pervasive social-emotional difficulties. Communication skill is an important correlate of disruptive behavior in typical development, and clarification of links between communication and aggression in ASD may inform intervention methods. We investigate child/family factors and communication in relation to aggression among 145 individuals with ASD (65 female; ages 8-17 years). Overall, more severe aggression was associated with younger age, lower family income, and difficulties with communication skills. However, this pattern of results was driven by males, and aggression was unrelated to child or family characteristics for females. Future work should incorporate these predictors in conjunction with broader contextual factors to understand aggressive behavior in females with ASD.

Heart rate mean and variability as a biomarker for phenotypic variation in preschoolers with autism spectrum disorder.

Interest in autonomic arousal in autism spectrum disorder (ASD) is increasing; however, reliability of these measures in ASD is unknown, and previously reported associations with social and cognitive abilities are inconsistent. This study assesses heart rate (HR) and HR variability (HRV) in preschoolers with ASD or typical development (TD) while they passively watched naturalistic videos. Measurement reliability, group differences, and the relationship with social and cognitive abilities were evaluated. Seventy one ASD and 66 TD children (2-4 years) provided cardiac data from two sessions. Test-retest intraclass correlations of HR and HRV over a 3-week period were moderate to good in both groups. Groups did not differ in mean level of HR or HRV. Intra-individual variability of HR between video segments within a session was higher in the ASD group, but intraclass correlations of this metric were low. Higher HR related to better language skills in TD children, but not after accounting for age and nonverbal ability. Higher HRV related to better expressive and receptive language in ASD children after controlling for age and nonverbal ability. HR/HRV were not related to social or executive functioning skills and did not explain any additional variance in abilities at a 12-month follow-up visit. In summary, variation in language abilities is associated with HR in the TD group and HRV in the ASD group. While preliminary, these results are promising for consideration of autonomic control as a biomarker for individual differences in ASD and may help us understand the mechanisms that contribute to communication skills. Autism Research 2019, 12: 39-52. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Cardiac activity, such as heart rate and heart rate variability, is linked to a wide range of psychological functions. This study shows that there is an association between heart rate and heart rate variability and language skills in young children with autism spectrum disorder (ASD). These results may help us understand what underlies individual differences in developmental abilities in young children with ASD.