Infants’ Motor Activity During a Mother–Infant Interaction Alternating Silent and Singing Phases

Abstract

Infants interact with their caregivers, using visual contact, smiling, vocalizations, and motor activity. Most of the studies on infant motor activity during dyadic interaction provided qualitative microanalyses. Few documented changes in infants’ general motor activity when facing social stimuli, but the movement analyses were carried out over large time windows. Following on from a previous study, we sought to explore rapid variations in motor activity during an interaction between mothers and their 6-month-old infants. The interaction featured short alternating silent and singing phases. Results showed that infants’ head, hand, and foot motor activity was related to their mothers’ behavior. Head movements, in particular, decreased during the songs and increased between them. The interindividual variability was strong at the hand and foot level and a k-mean cluster analysis showed three different group tendencies. Head stillness certainly expressed the infants’ attentional engagement in the interaction. Hand and foot movements appeared to be more variable and, at the foot level, presumably depended on the mother–infant communicative routines. Infants’ general motor activity could be an indicator of the infant’s engagement and reflect the dyad’s communicative routines during interactions.