Background: Across culture, healthy infants show a high interest in infant-directed (ID) talking and singing. Despite ID talking and ID singing being very similar in physical properties, infants differentially respond to each of them. The mechanisms underpinning these different responses are still under discussion.
Methods: This study explored the behavioral (n = 26) and brain (n = 14) responses from 6- to 8-month-old infants to ID talking and ID singing during a face-to-face mother-infant interaction with their own mother. Behavioral response was analyzed from offline video coding, and brain response was estimated from the analysis of electrophysiological recordings.
Results: We found that during ID talking, infants displayed a significantly higher number of visual contacts, vocalizations, and body movements than during ID singing. Moreover, only during ID talking were the number of visual contacts and vocalizations positively correlated with the number of questions and pauses in the mother's speech.
Conclusions: Our results suggest that ID talking provides infants with specific cues that allow them not only to react to mother stimulation, but also to act toward them, displaying a rudimentary version of turn-taking behavior. Brain activity partially supported that interpretation. The relevance of our results for bonding is discussed.
© 2016 S. Karger AG, Basel.