Clinical correlations of auditory P200 topography and left temporo-central deficits in schizophrenia: a preliminary study.

A number of studies using nontopographic analyses have reported an amplitude decrement of the auditory P200 component in schizophrenics compared to normal controls. Here we report a topographic analysis of the auditory P200 (204-272 ms; peak to baseline) in chronic medicated schizophrenics (N = 11) and normal controls (N = 18) and the correlation between this measure and clinical symptoms in schizophrenia. Exploratory T-statistic mapping (SPM) and "protected" Hotelling's T-squared contrasts of integrated voltages over the entire scalp showed that schizophrenics' P200 component had diminished amplitude in the left temporo-central region. Furthermore, P200 amplitude in the same scalp region during the experimental condition of counting infrequent tones was highly correlated with negative symptoms in the schizophrenic group.