ABSTRACT
As the body of research in support of a tight link between language processing and the cortical motor system rapidly grows (for recent reviews, see Fischer and Zwaan, 2008; Willems and Hagoort, 2007), so does the literature against the view that the neurobiological mechanisms ascribed to the Mirror Neuron Systems (MNS; Rizzolatti et al., 2008) provide exhaustive explanatory power for understanding the neural bases of language (Hickok, 2009; Lotto et al., 2009; Toni et al., 2008). MNS-based language theories posit that, in the course of hominid evolution, a specific class of perceptuo-motor neurons or so-called mirror neurons has incorporated the capacity to respond to communicative speech gestures. By analogy with the action execution-observation matching mechanism mediating action understanding, it has been speculated that the MNS may contribute to the understanding of communicative meaning (Rizzolatti and Craighero, 2004). In this theoretical position chapter, we will intentionally avoid any commitment concerning the hypothesis that language evolved from a more rudimentary combination of sensorimotor and cognitive functions [but see Tettamanti et al. (2009) for a detailed discussion of this issue]. In particular, we will not argue against nor in favor of the conjecture that linguistic communication evolved from manual gestures, as suggested by Corballis (2010) among others; or other type of motor control, as suggested by Toni et al. (2008) proposing that the evolution of language may be consequent to the emergence in humans of voluntary control over the vocal apparatus. Rather, we will argue that a single neurophysiological mechanism, such as the essential property of the MNS to map together perceptual and motor information, is inherently unable to explain all the manifold components of the human language system (for similar views, see Arbib, 2010; Corballis, 2010).
