Cortical responsiveness during inner speech in schizophrenia: an event-related potential study.
OBJECTIVE
The study assessed the effects of inner speech on auditory cortical responsiveness in schizophrenia.


METHODS
Comparison subjects (N=15) and patients with schizophrenia (N=15) were presented with acoustic and visual stimuli during three conditions: while subjects were silent, when spontaneous inner speech might occur; during directed inner speech, while subjects repeated a statement silently to themselves; and while subjects listened to recorded speech. N1 event-related potentials were recorded during the three conditions.


RESULTS
N1 event-related potentials elicited by acoustic stimuli, but not by visual stimuli, were lower during directed inner speech than during the silent baseline condition in the comparison subjects but not in the patients.


CONCLUSIONS
Abnormal auditory cortical responsiveness to inner speech in patients with schizophrenia may be a sign of corollary discharge dysfunction, which may potentially cause misattribution of inner speech to external voices.
Ford
J M
JM
Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, CA 94305-5550, USA. jford@stanford.edu
Mathalon
D H
DH
Kalba
S
S
Whitfield
S
S
Faustman
W O
WO
Roth
W T
WT
D000161:Acoustic Stimulation; D000328:Adult; D002540:Cerebral Cortex / Q000503:physiopathology*; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008606:Mental Processes; D008875:Middle Aged; D010775:Photic Stimulation; D012559:Schizophrenia / Q000503:physiopathology*; D013060:Speech / Q000502:physiology*; D014705:Verbal Behavior / Q000502:physiology*