Burkhardt-Reed, M. | Search bioRxiv

bioRxiv2020

Social and endogenous motivations in the emergence of canonical babbling: An autism risk study

There is a growing body of research emphasizing the role of social and endogenous motivations in human development. The present study evaluated canonical babbling across the second-half year of life using all-day recordings of 98 infants participating in a longitudinal study. Canonical babbling ratios were calculated from human coding along with Likert-scale ratings on vocal turn taking and vocal play in each segment. Ratios across all infants were significantly elevated during high turn taking and also during high vocal play. We conclude that both social and endogenous motivations may drive infants tendencies to produce their most advanced vocal forms.

developmental biology↗

bioRxiv2019

Social and non-social functions of infant vocalizations

Research on infant vocal development has provided notable insights into vocal interaction with caregivers, elucidating growth in foundations for language through parental elicitation and reaction to vocalizations. A role for infant vocalizations produced endogenously, potentially providing raw material for interaction and a basis for growth in the vocal capacity itself, has received less attention. We report that in laboratory recordings of infants and their parents, the bulk of infant speech-like vocalizations, or "protophones", were directed toward no one and instead appeared to be generated endogenously, mostly in exploration of vocal abilities. The tendency to predominantly produce protophones without directing them to others occurred both during periods when parents were instructed to interact with their infants and during periods when parents were occupied with an interviewer, with the infants in the room. The results emphasize the infant as an agent in vocal learning, even when not interacting socially and suggest an enhanced perspective on foundations for vocal language.

developmental biology↗