Mirroring other minds in monkeys: From development of mimicry to intersubjectivity
Pier Francesco Ferrari
Dipartimento di Biologia Evolutiva e Funzionale, Università di Parma, Italy
Mirror neurons have originally been described in the macaque premotor and parietal cortices, which are considered to be areas involved in sensorimotor transformations. The properties of these neurons allow an individual to understand others’ actions and are the basis of a non-inferential mechanism through which the macaque can understand others’ intentions. Recently, electroencephalography in newborn macaques has shown that motor areas become active during the observation of communicative gestures. Thus, infant macaques possess at birth a brain mechanism to connect with others, probably involving a mirror system.
The particular sensitivity of this system to others’ actions and emotions is suitable to tune the individual’s behaviour to others’ activities in order to coordinate, learn new motor skills and communicate. The capacity to copy the behavior of others has long been viewed as an expression of such sensitivity and as a mean that allow individuals to be emotionally connected with others. We explored this hypothesis and provided new experimental evidence of this association in monkeys (capuchin monkeys and gelada baboons). By looking at the ontogeny of mimicry behavior in macaques, we show that the infant capacity to imitate facial gestures is strongly connected with the development of intersubjectivity. Infants are not merely passive recipients of maternal solicitation but they actively participate and stimulate intersubjective exchanges. However, these interactions are not sustained and nurtured, thus limiting the impact that early emotional engagements could have in adult social life. The foundations of complex forms of communication and imitation that are typically expressed by apes and humans can be tracked in macaques and probably rely on an action-perception core mechanism that is present at birth and subserves early intersubjective exchanges.