The cortical computations underlying feedback control in vocal production
Current Opinion in Neurobiology
Recent neurophysiological studies of speaking are beginning to elucidate the neural mechanisms underlying auditory feedback processing during vocalizations. Here we review how research findings impact our state feedback control (SFC) model of speech motor control. We will discuss the evidence for cortical computations that compare incoming feedback with predictions derived from motor efference copy. We will also review observations from auditory feedback perturbation studies that demonstrate
... ar evidence for a state estimate correction process, which drives compensatory motor behavioral responses. While there is compelling support for cortical computations in the SFC model, there are still several outstanding questions that await resolution by future neural investigations. 21. Houde JF, Kort NS, Niziolek CA, Chang EF, Nagarajan SS: Neural evidence for state feedback control of speaking. Proceedings of Meetings on Acoustics 2013, 19:-. * This article describes the first study showing that speakers quickly compensate for perturbations of the formants of their auditory feedback of their ongoing speech, in a manner similar to the pitch perturbation reflex. * This extensive study employing many subjects, supported the claim that sensorimotor adaptation of speech exhibits very little generalization to novel contexts. The finding is consistent with the hypothesis that the representations controlling the production of different utterances are largely independent of each other. 40. Villacorta VM, Perkell JS, Guenther FH: Sensorimotor adaptation to feedback perturbations of vowel acoustics and its relation to perception.