Data from: Pre-linguistic infants employ complex communicative loops to engage mothers in social exchanges and repair interaction ruptures

Language has long been identified as a powerful communicative tool among
humans. Yet, pre-linguistic communication, which is common in many
species, is also used by human infants prior to the acquisition of
language. The potential communicational value of prelinguistic vocal
interactions between human infants and mothers has been studied in the
past decades. With 120 dyads (mothers and 3 or 6-month-old infants), we
used the classical Still-Face Paradigm (SFP) in which mothers interact
freely with their infants, then refrain from communication (Still Face,
SF), and finally resume play. We employed innovative automated techniques
to measure infant and maternal vocalization and pause, and dyadic
parameters (infant response to mother, joint silence and overlap) and the
emotional component of Infant Directed Speech (e-IDS) throughout the
interaction. We showed that : (1) during the initial free play mothers use
longer vocalizations and more e-IDS when they interact with older infants
and (2) infant boys exhibit longer vocalizations and shorter pauses than
girls. (3) During the SF and reunion phases, infants show marked and
sustained changes in vocalizations but their mothers do not and (4)
mother-infant dyadic parameters increase in the reunion phase. Our
quantitative results show that infants, from the age of 3 months, actively
participate to restore the interactive loop after communicative ruptures
long before vocalizations show clear linguistic meaning. Thus, auditory
signals provide from early in life a channel by which infants co-create
interactions, enhancing the mother-infant bond.