Sharing and synchrony of behavior states and heart rate in nondepressed versus depressed mother-infant interactions

Sharing and synchrony of behavior states and heart rate were assessed by spectral and cross-spectral analyses of the interaction data of 16 “depressed” and nondepressed mothers and their 3-month-old infants. The depressed mothers and their infants shared negative affective behavior states more often and positive behavior states less often than the nondepressed dyads. Cross-spectral analyses of the mothers' and infants' behavior and heart rate time series suggested the following: (a) greater coherence of mother-infant behavior states in nondepressed versus depressed dyads, with mothers leading at less than 1-s lags; (b) greater coherence of infant behavior/mother heart rate for the nondepressed versus depressed dyads; (c) no group differences for mother behavior/infant heart rate, for mother behavior/heart rate, for infant behavior/heart rate, or for mother/infant heart rate; and (d) greater coherence across partner behavior (mother/infant behavior) than within-partner behavior and physiology (mother behavior/heart rate or infant behavior/heart rate).