Explaining Facial Imitation: A Theoretical Model

Abstract

A long-standing puzzle in developmental psychology is how infants imitate gestures they cannot see themselves perform (facial gestures). Two critical issues are: (a) the metric infants use to detect cross-modal equivalences in human acts and (b) the process by which they correct their imitative errors. We address these issues in a detailed model of the mechanisms underlying facial imitation. The model can be extended to encompass other types of imitation. The model capitalizes on three new theoretical concepts. First, organ identification is the means by which infants relate parts of their own bodies to corresponding ones of the adult's. Second, body babbling (infants' movement practice gained through self-generated activity) provides experience mapping movements to the resulting body configurations. Third, organ relations provide the metric by which infant and adult acts are perceived in commensurate terms. In imitating, infants attempt to match the organ relations they see exhibited by the adults with those they feel themselves make. We show how development restructures the meaning and function of early imitation. We argue that important aspects of later social cognition are rooted in the initial cross-modal equivalence between self and other found in newborns.

Keywords: cross-modal; faces; imitation; memory; motor coordination; self.

Figure 1

A conceptual schematic of the active intermodal mapping hypothesis (AIM).

Figure 2

AIM model of the mechanisms underlying early facial imitation. The model depicts the functional relations among the external world, perceptual system, representational system, and action system. Representations of the external target (the adult demonstration) and the infant’s body are compared in terms of organ relations (see text). The solid arrows indicate current processing. The dotted arrow indicates prior learning from body babbling experience.

Figure 3

A diagram of infants’ correction process. Infants who are shown a novel gesture of tongue-protrusion-to-the-side (‘adult target’) progress through an ordered series of tongue movements (indicated by ‘1–4’). The direction and extent of the arrows depict the corresponding dimensions of the infants’ tongue protrusion responses. The responses are not randomly ordered, but rather exhibit a systematic convergence toward a more faithful match of the adult target (see text).

Figure 4

Six-week-old infants imitating the large tongue-protrusion-to-the side gesture demonstrated in the Meltzoff and Moore (1994) study. Such behaviour rarely occurs in baseline activity when infants have not been shown the gesture. Infants produce these imitative matches after correcting earlier approximations. The AIM model of early imitation accounts for such correction by postulating that infants are monitoring their unseen actions through proprioception (see text). The acts shown here correspond to step 4 in Figure 3.