Speech Science Forum: Dr Michel Belyk

Evolutionary neuroscience of speech motor control

Though humans are conspicuous as the only speaking animal, the neural adaptations that make humans eloquent, but not closely related species, are less obvious. One adaptation that has been well characterised is the neural control of the larynx and the voice. Whereas humans have direct cortical control over the muscles of the larynx, non-human primates have only indirect control which places limitations on voluntary movements of the laryngeal sound source. This feature of the human brain has been hypothesised to be a key prerequisite in the evolution of speech, and has strong parallels in the brains of other vocally talented species, such as songbirds. I will describe human brain imaging research that has explored how the neural control of the larynx contributes to key abilities such as the vocal imitation, and how it may go awry in disorders of speech such as stuttering.