Neurophysiological evidence of corollary discharge dysfunction in schizophrenia.
OBJECTIVE
Speaking is hypothesized to generate a corollary discharge of motor speech commands transmitted to the auditory cortex, dampening its response to self-generated speech sounds. Event-related potentials were used to test whether failures of corollary discharge during speech contribute to the pathophysiology of schizophrenia.


METHODS
The N1 component of the event-related potential elicited by vowels was recorded while the vowels were spoken by seven patients with schizophrenia and seven healthy comparison subjects and while the same vowels were played back.


RESULTS
In the healthy subjects, the N1 elicited by spoken vowels was smaller than the N1 elicited by played-back vowels. This reduction in N1 elicited by spoken vowels was not observed in the patients with schizophrenia.


CONCLUSIONS
These findings provide direct neurophysiological evidence for a corollary discharge that dampens sensory responses to self-generated, relative to externally presented, percepts in healthy comparison subjects and its failure in patients with schizophrenia.
Ford
J M
JM
Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, CA 943054-5550, USA. jford@stanford.edu
Mathalon
D H
DH
Heinks
T
T
Kalba
S
S
Faustman
W O
WO
Roth
W T
WT
D000328:Adult; D001303:Auditory Cortex / Q000503:physiopathology*; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000175:diagnosis / Q000503:physiopathology*; D012564:Schizophrenic Language; D013067:Speech Perception / Q000502:physiology*; D014705:Verbal Behavior / Q000502:physiology*