Social touch interacts with infants’ learning of auditory patterns

Infants' experiences are defined by the presence of concurrent streams of perceptual information in social environments. Touch from caregivers is an especially pervasive feature of early development. Using three lab experiments and a corpus of naturalistic caregiver-infant interactions, we examined the relevance of touch in supporting infants' learning of structure in an altogether different modality: audition. In each experiment, infants listened to sequences of sine-wave tones following the same abstract pattern (e.g., ABA or ABB) while receiving time-locked touch sequences from an experimenter that provided either informative or uninformative cues to the pattern (e.g., knee-elbow-knee or knee-elbow-elbow). Results showed that intersensorily redundant touch supported infants' learning of tone patterns, but learning varied depending on the typicality of touch sequences in infants' lives. These findings suggest that infants track touch sequences from moment to moment and in aggregate from their caregivers, and use the intersensory redundancy provided by touch to discover patterns in their environment.