Diminished Spontaneous Social Orienting in School-Age Children with ASD: ABC-CT Feasibility Study
Objectives: To evaluate if school-age children with ASD display impairments in SSO. We hypothesized that school-age children with ASD will show diminished attention to faces (%Face) in conditions involving ostensive cues for engagement and lower attention to social scenes (%Scene) in general.
Methods: Children with ASD (n=23) and typically developing (TD) controls (n=25) age 4 to 11 years completed the free-viewing SSO eye-tracking task validated previously in infant and toddler studies (Chawarska et al., 2012; 2013) as part of their participation in the Autism Biomarker Consortium for Clinical Trials (ABC-CT) study. Four conditions were presented in which actress: spoke directly to the camera (Speech), initiated Joint Attention (JA), made sandwich (Sandwich), and looked at moving toys (Toys). Group differences were analyzed using linear mixed models (LMM) with diagnosis and condition as factors and IQ as a covariate.
Results: A LMM analysis of %Face indicated effects of diagnosis (p=.009), condition (p<.001) and their interaction (p<.003) as well as IQ (p<.001). Compared to TD controls, children with ASD had lower %Face in the Speech and JA conditions (p<.001, p=.018), but not in the Toys and Sandwich conditions (p=.099, p=.860). LMM analysis on %Scene indicated no effect of diagnosis (p=.25), but significant condition (p<.001) and diagnosis x condition interactions (p<.001). Within subject comparisons indicated that, in the TD group, attention to the scene in the Speech condition was either comparable (JA and Toys) or higher (Sandwich) than in other conditions. In the ASD group, attention to the scene during the Speech condition was comparable to JA condition, but lower than in Toys and Sandwich conditions. Lower %Scene and %Face during the SSO task was associated with higher total SRS scores in the ASD group (Pearson r(22)=-.5 and r(22)=-.45, ps < .05).
Conclusions: Increasing attentional capacity in school-age children resulted in less pronounced differences in the overall attention to the scene. However, this increased capacity did not eliminate ASD-specific impairment in attention to faces of interactive partners. The study replicates and extends earlier findings and suggests that the SSO task represents a promising biomarker for ASD from prodromal stages of the disorder to early school age.