CORRELATION OF AUDITORY ODDBALL P300 WITH VERBAL MEMORY DEFICITS IN SCHIZOPHRENIA

Background. The study attempts to recruit well known 'cognitive' event related potential measures as an objective estimate of cognitive and specific memory impairment in schizophrenia. Methods. We examined 19 s chizophrenic patients and 28 healthy controls using an auditory discri mination task to elicit event related potentials, and a number of neur opsychological tests, including tests of general intellectual ability, putative frontal lobe function and verbal memory. Results. The late p ositive deflection presumed to be associated with stimulus evaluation (P300) was of lower amplitude and had a longer latency in the patients compared with controls of similar age and sex. We found correlations between P300 amplitude and latency, and neuropsychological performance scores in patients. There were correlations between decreased P300 am plitude and lower IQ and poorer memory performance, in particular, abn ormal semantic clustering, discriminability and intrusion errors. Incr eased P300 latency was correlated with lower pre-morbid IQ, poorer tot al memory scores and serial clustering, but paradoxically less relativ e retrieval deficit and fewer intrusion errors. Conclusions. These fin dings suggest that abnormal P300 is generally more likely to occur in patients with memory impairment.