How self-generated experience contributes to the development of speech and language in human infants?
Everyday experience plays a central role in the development of perceptual and cognitive abilities. Our latest studies have been exploring the non-obvious and obvious effects of perceptual experience on the development of audiovisual speech and language perception in human infants. Using eye tracking technology, we have discovered that when infants begin babbling and, thus, start learning to speak their native language, they begin to shift their attention to the interlocutor’s mouth to access redundant, audiovisual speech cues. This shift is self-generated and, thus, is evidence of the non-obvious effects of experience. We have also found that once infants start to master their native speech forms and begin to acquire native-language expertise, they begin to shift their attention to the interlocutor’s eyes to access social cues. They only make this shift, however, in response to their native language reflecting the specific effects of native-language experience. In this talk, I will present the latest findings from several new studies in which we have explored bilingual infants’ shifting patterns of audiovisual attention, the separate contribution of the audible and visible attributes of audiovisual speech information to the developmental shift in selective attention, and the importance of the temporal synchrony of the audible & visible attributes of audiovisual speech to the observed changing developmental pattern of selective attention. Together, these findings provide new insights into the mechanisms underlying the developmental acquisition of audiovisual speech & language skills in human infancy.