Latent inhibition effects reflected in event-related brain potentials in healthy controls and schizophrenics.
The present study examined the effects of pre-exposure of an irrelevant stimulus on reaction time and the contingent negative variation (CNV) in healthy controls and schizophrenic patients. In Phase I, subjects were either pre-exposed (PE) or not pre-exposed (NPE) to repeated presentations of an auditory probe stimulus (white noise), while engaged in counting auditory nonsense syllables. In Phase II, all subjects were required to produce a rapid motor response to a visual imperative stimulus that was preceded by the previously irrelevant auditory stimulus. During Phase II in controls, for PE as compared to NPE subjects, the build-up of CNV across trials was delayed. In schizophrenics, for both PE and NPE subjects, there was no pre-exposure effect on the CNV component. These findings indicate that ERPs may be useful in explicating the normal latent inhibition effect (poor associative learning to a stimulus after it has been passively pre-exposed) and its disruption in schizophrenia.
Guterman
Y
Y
Yezreel College, Israel.
Josiassen
R C
RC
Bashore
T E
TE
Johnson
M
M
Lubow
R E
RE
D000328:Adult; D001143:Arousal / Q000502:physiology; D001288:Attention / Q000502:physiology; D002540:Cerebral Cortex / Q000503:physiopathology; D003265:Contingent Negative Variation / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009433:Neural Inhibition / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D012016:Reference Values; D012559:Schizophrenia / Q000175:diagnosis / Q000503:physiopathology*; D012565:Schizophrenic Psychology