Trajectories of Maternal Behavior, Infant's Respiratory Sinus Arrhythmia, and Emotional Recovery Following the Still Face Paradigm.

The development of emotion regulation is integral to children's socioemotional adjustment. Respiratory sinus arrhythmia (RSA) reflects parasympathetic regulation of cardiac arousal and is thought to be an indicator of emotion regulation. However, it is unclear how RSA is associated with positive maternal behaviors and infant emotional recovery in real time over the course of a recovery period following a social stressor. Mothers and their 5- to 6-month-old infants (N = 143) completed the Still Face paradigm. Using a series of autoregressive latent trajectory models, the current study aimed to elucidate the associations among observed maternal warmth, infant RSA, and observed infant negative affect across a 5-min observation. The hypotheses were that trajectories of maternal warmth would predict trajectories of infant RSA and negative affect, and that trajectories of RSA would be associated with the infants' observed negative affect. Change in maternal warmth was associated with infant negative affect and RSA at the end of the reunion and change in RSA was associated with ultimate levels of negative affect. The results provide partial support for our hypothesis that maternal warmth supports infant physiological, and in turn, emotional recovery.