Reduced communication between frontal and temporal lobes during talking in schizophrenia.
BACKGROUND
Communication between the frontal lobes, where speech and verbal thoughts are generated, and the temporal lobes, where they are perceived, may occur through the action of a corollary discharge. Its dysfunction may underlie failure to recognize inner speech as self-generated and account for auditory hallucinations in schizophrenia.


METHODS
Electroencephalogram was recorded from 10 healthy adults and 12 patients with schizophrenia (DSM-IV) in two conditions: talking aloud and listening to their own played-back speech. Event-related electroencephalogram coherence to acoustic stimuli presented during both conditions was calculated between frontal and temporal pairs, for delta, theta, alpha, beta, and gamma frequency bands.


RESULTS
Talking produced greater coherence than listening between frontal-temporal regions in all frequency bands; however, in the lower frequencies (delta and theta), there were significant interactions of group and condition. This finding revealed that patients failed to show an increase in coherence during talking, especially over the speech production and speech reception areas of the left hemisphere, and especially in patients prone to hallucinate.


CONCLUSIONS
Reduced fronto-temporal functional connectivity may contribute to the misattribution of inner thoughts to external voices in schizophrenia.
Ford
Judith M
JM
Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, California 94305-5550, USA.
Mathalon
Daniel H
DH
Whitfield
Susan
S
Faustman
William O
WO
Roth
Walton T
WT
D000328:Adult; D001931:Brain Mapping; D004292:Dominance, Cerebral / Q000502:physiology; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology*; D006212:Hallucinations / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology; D012559:Schizophrenia / Q000503:physiopathology*; D012564:Schizophrenic Language; D013067:Speech Perception / Q000502:physiology*; D013702:Temporal Lobe / Q000503:physiopathology*; D014705:Verbal Behavior / Q000502:physiology*