Reflecting on imitation in autism: introduction to the special issue.

In response to our call for papers for a special issue of Journal of Experimental Child Psychology on functions and mechanisms of imitation in childhood, we received a surprisingly large number of manuscripts on a wide range of topics. We were happy and encouraged that so much interesting work is being done on imitation, and sorry that space and time constraints meant that we could not publish more of them. We ended up with two special issues, one on imitation in children with autism (the current issue) and one on imitation in typically-developing children (forthcoming). Here we provide a brief introduction to the three papers that constitute the current issue on autism and offer some speculation on how these papers might shed light on one of the more keenly debated topics in recent developmental psychopathology research: the association between autism and a dysfunctional mirror system. The identification of mirror neurons in the monkey prefrontal cortex (di Pellegrino, Fadiga, Fogassi, Gallese, & Rizzolatti, 1992; Gallese, Fadiga, Fogassi, & Rizzolatti, 1996; Rizzolatti, Fadiga, Fogassi, & Gallese 1996) and subsequent mapping of the analogue mirror system in humans (Iacoboni et al., 1999) have been hyped as being among the most important psychological discoveries in the last two decades. Indeed, it has been suggested that the mirror system may provide a unifying framework for understanding a host of human abilities including empathy, language, and theory of mind: Mirror neurons, it has been famously claimed, will do for psychology what DNA did for biology (Ramachandran, 2000). Of most relevance to the current issue, (1) the mirror system is considered to play a major role in the development and expression of imitation and (2) the symptoms associated with autism have been proposed to be directly attributable to mirror neuron dysfunction (see below). However, the papers in this issue provide information that calls some of these claims into question and that helps provide the foundation for a new perspective. Originally discovered in macaque monkeys, mirror neurons were found to fire both when the monkey performed a specific action (e.g., reaching for a peanut) and when it observed someone else performing the same action. Such direct mapping of produced and seen actions has seemingly obvious implications for imitation. Indeed, a number of theorists have linked the mirror system to imitation, typically based on the assumption that imitation fundamentally relies on a mechanism that ‘‘directly maps a pictorial or kinematic description of the observed action onto an internal motor representation of the same action” (Iacoboni et al., 1999, p. 2526). There are problems with this so-called ‘‘direct matching hypothesis,” though (Southgate, Gergely, & Csibra, in press; Southgate & Hamilton, 2008; Turella, Pierno, Tubaldi, & Castiello, in press). To begin with, monkeys, the only animal in which mirror neurons have been directly identified, are notoriously bad at imitation (Tomasello & Call, 1997). It has thus been suggested that mirror neurons are necessary but not sufficient for imitation to emerge: