Colloquium | March 13 | 4 p.m. | Tolman Hall, Beach Room 3105
John Houde, Speech & Nuroscience Lab Otolaryngology UC San Francisco
An important part of understanding the neural control of speech is determining how auditory feedback is processed during speaking. The behavioral phenomena associated with auditory feedback suggest a paradox about its role: it need not be present for intelligible speech production, but if it is present, it needs to be correct or speech output will be affected. For this reason, current models of speech motor control relegate auditory feedback to a more indirect role, with an inner feedback loop within the CNS that directly controls speech output, and a slower outer feedback loop where the possibly delayed and intermittent sensory feedback updates the internal feedback loop. Such models can be described as variations on the general theory of state feedback control (SFC). Here we show, via numerical simulations, how the SFC model can account not only for what is known about the behavioral role of auditory feedback in speaking, but also many of the findings about neural responses to auditory feedback. These include (1) the suppressed response in auditory cortex to self-produced speech (speaking-induced suppression (SIS)), (2) the enhanced response in auditory cortex to auditory feedback perturbations heard during speaking (speech perturbation response enhancement (SPRE)), and (3) the finding that in auditory areas exhibiting SPRE, neural responses to auditory feedback perturbations are highly correlated a speakers compensatory responses to these perturbations.