Towards a developmental cognitive science. The implications of cross-modal matching and imitation for the development of representation and memory in infancy.

This chapter began with a query about whether there was any content to an enterprise called "developmental cognitive science," and if so, whether the findings could inform work in adult cognition and neuropsychology. Both questions can now be answered in the affirmative. Evidence has been marshaled from infant studies concerning five topics of enduring interest in the cognitive and neuro-sciences: cross-modal integration, imitation, the coordination of perception and action, memory, and representation. The data show that young human infants can detect equivalences between information picked up by different sensory modalities. This was demonstrated both in tactual-visual perception of objects and auditory-visual perception of speech. Results also show that perception and production are intertwined literally from the earliest phases of infancy, with 4-month-olds demonstrating vocal imitation and newborns reproducing elementary gestures they saw an adult perform. There seems to be a transparency between the perceptual and motor systems, and it is conceivable that they may draw on the same internal code. Infants' proclivity to imitate was used to investigate early memory. It was found that young infants were not constrained to immediate mimicry, but could imitate after significant delays. The findings support the inference that infants, perhaps as early as birth, have a functioning memory system that cannot be reduced to "habit formation" or an exclusively "procedural memory." It was proposed instead that there is a kernel of some higher level memory system right from the earliest phases of human infancy. This does not imply that there is no development in the representational world of infants. Data were reviewed suggesting that there is a watershed transformation in childhood cognition at about 18 months of age. However, this is not a change from a stage in which there was a purely sensorimotor or habit-based system. Rather the development was characterized as a shift from using empirical or experience-based representations to using hypothetical representations, which concern possible realities. This developmental shift allows children to project into the future "what must be" and deduce from the past "what must have been," in advance of, and sometimes in the absence of, strictly perceptual evidence. This capacity provides the underpinnings for the conduct of science itself. Its origins are to be found in infancy.