Neural evidence for state feedback control of speaking

Abstract

An important recent development in neuroscience has been the use of models based on state feedback control (SFC) to explain the role of the central nervous system in motor control. In SFC, control is based on internal feedback of an estimate of the dynamic state of the thing (e.g., arm) being controlled. Within the internal loop, the state is predicted from outgoing motor commands and corrected by comparing the feedback expected to result from this state with actual incoming sensory feedback. SFC has received scant attention in the speech community, but the indirect role it suggests for feedback can account for much of what is known about the role of feedback in speech motor control. Our lab has been investigating how well SFC also accounts for the neural correlates of auditory feedback processing during speaking. Our principal approach has used magnetoencephalography to record the cortical activity of speakers as they hear themselves speaking, but recently, we have also completed an auditory feedback study based on electrocorticography. Many of the results of these studies have supported the SFC model, but some have posed challenges for it, which will be discussed. © 2013 Acoustical Society of America.