Impaired alpha and beta modulation in response to social stimuli in children with autism spectrum disorder

BackgroundEarly preferential attention to biological motion is a fundamental mechanism priming the development of sophisticated skills to detect and react to social stimuli. Children diagnosed with autism spectrum disorders (ASD) demonstrate reduced visual orientation towards biological motion, however, the underlying neurobiological mechanisms are unknown. MethodsWe measured the neural oscillations in children with ASD (n=34, mean age 3.43 years) and age and gender matched typically developing children (TD, n=27) while watching videos of social biological (BM) and geometrical motion (GM). Their visual interest in BM stimuli was measured with eye-tracking techniques. Neural oscillations were measured as amplitude modulation of the frequency bands with the electroencephalogram and calculated as the power ratio between BM and GM conditions using scalp and brain source reconstruction analyses. ResultsWe observed a reduced visual exploration of the BM stimuli along with (1) unchanged sensorimotor mu rhythm and (2) altered cortical alpha and beta power ratio in widespread right prefrontal areas associated with default mode and fronto-parietal networks in young children with ASD as compared to their TD peers. Furthermore, we measured significant correlations between prefrontal and posterior cingulate regions of the default mode network with the developmental quotient in both the ASD and TD groups. ConclusionWe observed abnormal alpha and beta modulation of the fronto-parietal and default mode networks along with altered visual exploration of the social biological motion. These deficits represent core impairments of the disorder and may be informative in developing future behavioural and neuroregulation interventions, such as neurofeedback.