Infant autonomic nervous system response and recovery: Associations with maternal risk status and infant emotion regulation.

This study examined whether risk status and cumulative risk were associated with autonomic nervous system reactivity and recovery, and emotion regulation in infants. The sample included 121 6-month-old infants. Classification of risk status was based on World Health Organization criteria (e.g., presence of maternal psychopathology, substance use, and social adversity). Heart rate, parasympathetic respiratory sinus arrhythmia, and sympathetic preejection period were examined at baseline and across the still face paradigm. Infant emotion regulation was coded during the still face paradigm. Infants in the high-risk group showed increased heart rate, parasympathetic withdrawal, and sympathetic activation during recovery from the still face episode. Higher levels of cumulative risk were associated with increased sympathetic nervous system activation. Moreover, increased heart rate during recovery in the high-risk group was mediated by both parasympathetic and sympathetic activity, indicating mobilization of sympathetic resources when confronted with socioemotional challenge. Distinct indirect pathways were observed from maternal risk to infant emotion regulation during the still face paradigm through parasympathetic and sympathetic regulation. These findings underline the importance of specific measures of parasympathetic and sympathetic response and recovery, and indicate that maternal risk is associated with maladaptive regulation of stress early in life reflecting increased risk for later psychopathology.