title: Auditory cortex processes variation in our own speech.
abstract: As we talk, we unconsciously adjust our speech to ensure it sounds the way we intend it to sound. However, because speech production involves complex motor planning and execution, no two utterances of the same sound will be exactly the same. Here, we show that auditory cortex is sensitive to natural variations in self-produced speech from utterance to utterance. We recorded event-related potentials (ERPs) from ninety-nine subjects while they uttered "ah" and while they listened to those speech sounds played back. Subjects' utterances were sorted based on their formant deviations from the previous utterance. Typically, the N1 ERP component is suppressed during talking compared to listening. By comparing ERPs to the least and most variable utterances, we found that N1 was less suppressed to utterances that differed greatly from their preceding neighbors. In contrast, an utterance's difference from the median formant values did not affect N1. Trial-to-trial pitch (f0) deviation and pitch difference from the median similarly did not affect N1. We discuss mechanisms that may underlie the change in N1 suppression resulting from trial-to-trial formant change. Deviant utterances require additional auditory cortical processing, suggesting that speaking-induced suppression mechanisms are optimally tuned for a specific production.
authors.affiliation: Mental Health Service, San Francisco Veterans Affairs Medical Center, San Francisco, California, United States of America.
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Sitek
authors.affiliation: Mental Health Service, San Francisco Veterans Affairs Medical Center, San Francisco, California, United States of America ; Department of Psychiatry, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Mathalon
authors.affiliation: Mental Health Service, San Francisco Veterans Affairs Medical Center, San Francisco, California, United States of America.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Roach
authors.affiliation: Department of Otolaryngology, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: John F
authors.initials: JF
authors.lastname: Houde
authors.affiliation: Department of Otolaryngology, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Caroline A
authors.initials: CA
authors.lastname: Niziolek
authors.affiliation: Mental Health Service, San Francisco Veterans Affairs Medical Center, San Francisco, California, United States of America ; Department of Psychiatry, University of California San Francisco, San Francisco, California, United States of America.
authors.forename: Judith M
authors.initials: JM
authors.lastname: Ford
mesh_terms: D000328:Adult; D001303:Auditory Cortex / Q000502:physiology*; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D013067:Speech Perception / Q000502:physiology*