Effects of task relevance and attention on P3 in schizophrenic patients.
The P3 component of the event-related potentials (ERPs) to auditory task-relevant and task-irrelevant stimuli in 'Attend Auditory' (i.e., reaction time task) and 'Attend Visual' (i.e., when the auditory stimuli were being ignored) conditions was investigated in 13 RDC/DSM-III diagnosed schizophrenic patients. ERPs were recorded from Fz, Cz, and Pz. Compared to controls, schizophrenics had a significantly smaller P3 in the Attend Auditory than in the Attend Visual condition and to the task-relevant than to the task-irrelevant stimuli. Furthermore, the patients' P3 response to the most salient task-irrelevant stimuli in the Attend visual condition was normal. The results are discussed as suggesting that schizophrenics either allocate relatively more resources to task-irrelevant than task-relevant stimuli or that they fail to habituate to task-irrelevant stimuli.
Grillon
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C
Department of Psychiatry, Yale University School of Medicine, New Haven, CT 06510-3223.
Ameli
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R
Courchesne
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E
Braff
D L
DL
D000328:Adult; D001143:Arousal / Q000502:physiology*; D001288:Attention / Q000502:physiology*; D002540:Cerebral Cortex / Q000503:physiopathology; D003118:Color Perception / Q000502:physiology; D004569:Electroencephalography / Q000295:instrumentation; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010897:Pitch Discrimination / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology; D012559:Schizophrenia / Q000175:diagnosis* / Q000503:physiopathology; D012565:Schizophrenic Psychology; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation