Respiratory sinus arrhythmia: a marker for positive social functioning and receptive language skills in children with autism spectrum disorders.

The current study builds on the emerging autism spectrum disorder (ASD) literature that associates autonomic nervous system activity with social function, and examines the link between respiratory sinus arrhythmia (RSA) and both social behavior and cognitive function. The RSA response pattern was assessed in 23 4- to 7-year-old children diagnosed with an ASD. Higher baseline RSA amplitudes were associated with better social behavior (i.e., more conventional gestures, more instances of joint attention) and receptive language abilities. Similar to reports of typically developing children, ASD children with higher RSA amplitude at baseline showed greater RSA and HP reactivity during an attention-demanding task. These results highlight the importance of studying RSA as a marker of positive function in children with ASD.