A bilateral cortical network responds to pitch perturbations in speech feedback.
Auditory feedback is used to monitor and correct for errors in speech production, and one of the clearest demonstrations of this is the pitch perturbation reflex. During ongoing phonation, speakers respond rapidly to shifts of the pitch of their auditory feedback, altering their pitch production to oppose the direction of the applied pitch shift. In this study, we examine the timing of activity within a network of brain regions thought to be involved in mediating this behavior. To isolate auditory feedback processing relevant for motor control of speech, we used magnetoencephalography (MEG) to compare neural responses to speech onset and to transient (400ms) pitch feedback perturbations during speaking with responses to identical acoustic stimuli during passive listening. We found overlapping, but distinct bilateral cortical networks involved in monitoring speech onset and feedback alterations in ongoing speech. Responses to speech onset during speaking were suppressed in bilateral auditory and left ventral supramarginal gyrus/posterior superior temporal sulcus (vSMG/pSTS). In contrast, during pitch perturbations, activity was enhanced in bilateral vSMG/pSTS, bilateral premotor cortex, right primary auditory cortex, and left higher order auditory cortex. We also found speaking-induced delays in responses to both unaltered and altered speech in bilateral primary and secondary auditory regions, left vSMG/pSTS and right premotor cortex. The network dynamics reveal the cortical processing involved in both detecting the speech error and updating the motor plan to create the new pitch output. These results implicate vSMG/pSTS as critical in both monitoring auditory feedback and initiating rapid compensation to feedback errors.
Department of Radiology, University of California, San Francisco, and University of California, Berkeley USA; Joint Graduate Group in Bioengineering, University of California, San Francisco, USA. Electronic address: naomi.kort@ucsf.edu.
Naomi S
NS
Kort
Department of Radiology, University of California, San Francisco, and University of California, Berkeley USA. Electronic address: Srikantan.Nagarajan@ucsf.edu.
Srikantan S
SS
Nagarajan
Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, USA. Electronic address: houde@phy.ucsf.edu.
John F
JF
Houde
D000161:Acoustic Stimulation / Q000379:methods; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D025461:Feedback, Physiological / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D010898:Pitch Perception / Q000502:physiology*; D013060:Speech / Q000502:physiology*
Auditory feedback; Magnetoencephalography; Sensorimotor; Speech motor control