Auditory P300 event-related potentials and neuropsychological performance in schizophrenia and bipolar affective disorder.
ABSTRACT The auditory P300 event-related potential (ERP) and performance on neuropsychological tests were evaluated in 26 subjects with schizophrenia, 19 with bipolar affective disorder, and 27 controls. The schizophrenic and the bipolar groups were similar in having prolonged P300 latency recorded from central and temporal leads. The P300 was significantly reduced in amplitude in the schizophrenic group at midline leads and the left temporal lead but was not significantly reduced in amplitude at any electrode site when the bipolar group was compared to controls. Schizophrenics performed significantly less well than bipolars and controls on tests of verbal fluency and, within this group, a significant correlation was found between the latency of P300 and verbal fluency test scores. While the bipolar group of patients was similar to the schizophrenic group in having prolonged P300 latency, these groups differed in P300 amplitude, performance on verbal fluency tests, and the relationship between the physiological and neuropsychological variables.
The British Journal of Psychiatry 03/2004; 184(3):223-230. DOI:10.1192/bjp.184.3.223 · 7.34 Impact Factor
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ABSTRACT: Decreased delta oscillation upon cognitive load is common in patients with Alzheimer‘s disease, mild cognitive impairment, and schizophrenia. However, there is no previous study analyzing the delta responses in euthymic medication-free patients with bipolar disorder. Participants comprised 22 euthymic medication-free patients with DSM-IV diagnoses of bipolar disorder and 21 healthy controls who were matched to the patients for sex, age, and education. Electroencephalographic activity was recorded at 30 electrode sites using an application of an auditory oddball paradigm. The maximum peak-to-peak amplitudes for each subject‘s averaged delta response (0.5–3.5 Hz) were measured. There was a significant intergroup difference in evoked and event-related delta (0.5–3.5 Hz) responses. Post hoc comparisons revealed that the event-related delta oscillatory responses of the bipolar patient group were significantly lower than those of the healthy control group over the temporoparietal and occipital electrode sites. Euthymic bipolar patients showed reduced event-related delta oscillatory responses in comparison to healthy subjects under cognitive load. The decrease of delta oscillations may be a common phenomenon that can be observed in different neuropsychiatric disorders with cognitive dysfunction.Psychiatry Research Neuroimaging 07/2014; DOI:10.1016/j.pscychresns.2014.04.001 · 2.83 Impact Factor