Relationship between respiratory sinus arrhythmia, heart period, and caregiver-reported language and cognitive delays in children with autism spectrum disorders.

The present study examines the relationship between autonomic activity and cognitive/language delays in children with autism spectrum disorder (ASD). Baseline levels of respiratory sinus arrhythmia (RSA) and heart period (HP) were assessed in 23 4-7-year old children diagnosed with ASD. The relationship between RSA, HP, and ASD behavioral symptoms was examined. Similar to prior studies on typically developing children, lower basal RSA was related to more caregiver-reported language and cognitive delays, and to the lack of language.