8 - How infants detect information in biological motion

Summary

The ability to detect and then interpret meaning within biological motion is one of the great mysteries of early human development. Human infants are remarkably good at disambiguating aspects of the visual world such that key information is rapidly processed. This is in many ways a marvel of evolution. After all, what information is more complex, continuous, and dynamic than human movement? This ability is particularly surprising when the range of information conveyed spans from “low level” perceptual information, such as organismic structure, through to complicated social knowledge, such as intentions and beliefs embedded within action.

This chapter will outline the current state of our knowledge associated with biological motion (BM) processing by infants, drawing heavily on recent work derived from electrophysiological methodologies (such as electroencephalogram [EEG] and event-related brain potentials [ERPs], see below) rather than behavioral techniques. This emphasis is partly due to the recency of these findings, and partly because they generate important new research questions. As EEGs and ERPs can allow the investigation of infant processing capacities in the absence of overt behavioral responses, these techniques provide an important tool in the arsenal of any given infancy researcher. They do, however, produce different results to work conducted via behavioral paradigms, occasionally making comparisons between the two methodologies problematic when investigating the same research area. In order to present the EEG and ERP area, I briefly outline how these techniques are used. In this review, I focus on the perception of biological motion during infancy. Through the introduction of the concept of the directed attention model of infant social cognition, I present how this capacity cascades via the perception of human movement into a wider corpus of skills present in early social-cognitive processing, including intention detection and interpretation.