Speech perception when the motor system is compromised

Abstract

In a recent contribution, Lotto, Hickok and Holt[1] have made a compelling argument that findings on mirror neurons do not support a strong version of the motor theory of speech perception. However they go further in arguing that there is “little evidence that motor activity plays a necessary part in perception”, a claim based primarily on the observation that speech production can be impaired in syndromes such as Broca's aphasia while leaving comprehension relatively intact[2]. Alternatively, this dissociation could reflect redundancy in the speech perception network, coupled with preserved access to top-down contextual information. So the dissociation doesn't rule out a role for the motor system in speech perception, a view supported by several lines of evidence.