[Synchronization between preverbal vocalizations and motor actions in early infancy. I: Pre-canonical babbling vocalizations synchronize with rhythmic body movements before the onset of canonical babbling].

ABSTRACT

This study reports the synchronization between vocal behaviors and motor actions in infants at the prelinguistic stage. Four Japanese infants were studied from the age of 4-6 months to 11 months. For all infants, a 40-min segment was selected from the 60-90 min observation recording taken on each month. All the vocalizations and motor actions recorded in the segment were transcribed. The results show that a behavioral synchronization occurred between vocalizations and rhythmic actions in infants at the prelinguistic stage. The synchronization was particularly obvious in the month immediately before the onset of canonical babbling. These findings suggest that the synchronization between vocalizations and rhythmic actions may have the function of promoting infants to produce canonical babbling, that is indispensable for the acquisition of spoken language.