Autonomic response in autism spectrum disorder: Relationship to social and cognitive functioning.

Individuals with autism spectrum disorder (ASD) may exhibit chronic autonomic nervous system (ANS) hyperarousal (e.g., lower respiratory sinus arrhythmia and higher heart rate) compared to their typically developing peers, reflecting a chronic biological threat response. The sustained nature of this cardiac threat suggests tonic nervous system perception of threat in safe contexts. Herein, the cardiac literature in adult and child populations with ASD is reviewed and placed within a continuum of functioning in order to inform the relationship between cardiac response and functioning in ASD. Findings from this review support the relationship between chronic autonomic hyperarousal and emotional and behavioral difficulties observed in individuals with ASD.