title: Neuronal mechanisms of voice control are affected by implicit expectancy of externally triggered perturbations in auditory feedback.
abstract: Accurate vocal production relies on several factors including sensory feedback and the ability to predict future challenges to the control processes. Repetitive patterns of perturbations in sensory feedback by themselves elicit implicit expectations in the vocal control system regarding the timing, quality and direction of perturbations. In the present study, the predictability of voice pitch-shifted auditory feedback was experimentally manipulated. A block of trials where all pitch-shift stimuli were upward, and therefore predictable was contrasted against an unpredictable block of trials in which the stimulus direction was randomized between upward and downward pitch-shifts. It was found that predictable perturbations in voice auditory feedback led to a reduction in the proportion of compensatory vocal responses, which might be indicative of a reduction in vocal control. The predictable perturbations also led to a reduction in the magnitude of the N1 component of cortical Event Related Potentials (ERP) that was associated with the reflexive compensations to the perturbations. We hypothesize that formation of expectancy in our study is accompanied by involuntary allocation of attentional resources occurring as a result of habituation or learning, that in turn trigger limited and controlled exploration-related motor variability in the vocal control system.
authors: Department of Communication Sciences and Disorders, Northwestern University, Evanston, Illinois, United States of America. o-korzyukov@northwestern.edu
authors: Oleg
authors: O
authors: Korzyukov
authors: Lindsey
authors: L
authors: Sattler
authors: Roozbeh
authors: R
authors: Behroozmand
authors: Charles R
authors: CR
authors: Larson
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001303:Auditory Cortex / Q000502:physiology; D001519:Behavior; D003142:Communication; D004569:Electroencephalography / Q000379:methods; D005071:Evoked Potentials; D056228:Feedback, Sensory; D005260:Female; D006801:Humans; D008297:Male; D009474:Neurons / Q000502:physiology*; D010898:Pitch Perception / Q000502:physiology; D011930:Reaction Time; D012815:Signal Processing, Computer-Assisted; D013060:Speech; D013061:Speech Acoustics; D014831:Voice; D055815:Young Adult