Infant affective reactions to the resumption of maternal interaction after the still-face.

To investigate infants' reactions to the Face-to-Face Still-Face Paradigm and in particular the reunion episode, 50 6-month-olds' affective, behavioral, and physiologic reactions were recorded and analyzed. Infants reacted to the still-face with negative affect, a drop in vagal tone, and an increase in heart rate. By contrast, they reacted to the reunion episode with a mixed pattern of positive and negative affect. There was a carryover of negative affect from the still-face, an increase in fussiness and crying, and a rebound of positive affect. During this episode, the infants' heart rate and vagal tone returned to initial levels. The data indicate that infant affective displays are specifically related to different interactive events, but that their physiologic reactions do not show the same level of specificity. The findings also highlight the complexity of the affective and reparatory processes that take place in mother-infant interactions.