Sympathetic Under-Arousal and Externalizing Behavior Problems in Children with Autism Spectrum Disorder.

Children with autism spectrum disorder (ASD) commonly exhibit co-occurring externalizing behavior problems, which can impede learning opportunities and contribute significantly to caregiver stress. Substantial theory and research has linked under-arousal of the sympathetic nervous system to increased externalizing problems in children without ASD, but under-arousal has not been considered as an explanatory mechanism for individual differences among children with ASD. We tested the notion that lower electrodermal activity (EDA) would predict more externalizing problems in children with ASD, and considered the degree to which parent co-regulatory support could buffer this risk. Forty children with ASD between the ages of 4 and 11 years and their primary caregivers participated in a laboratory visit that included various play, compliance, and problem-solving regulatory tasks. EDA was measured through wireless wrist sensors, parental scaffolding was observed during a dyadic problem-solving task, and parents rated their children's externalizing behavior problems. As predicted, low EDA during the compliance-oriented tasks directly predicted higher child externalizing problems. Parental scaffolding moderated the link between under-arousal during the problem-solving regulatory tasks and externalizing problems such that the relation was observed in the context of low, but not high, support. Implications for relevant theories (e.g., fearlessness theory, stimulation-seeking theory) are discussed, and the potential for psychophysiological patterns to inform intervention with these children is considered.