The topography of the postimperative negative variation
(PINV) was analyzed in participants with high and low scores
on the German version of the Schizotypal Personality Questionnaire.
Scalp amplitude and Laplacian maps of the terminal contingent
negative variation (tCNV) and PINV and the time course
of the PINV were compared between the two groups. CNV and
PINV were induced with a delayed matching-to-sample task,
in which the pattern of the imperative stimulus was either
clearly or ambiguous matched to one of the two diamonds
simultaneously presented as a warning stimulus 4.0 s earlier.
Electroencephalograms were recorded with a DC amplifier
(32 channels). Negativity increased from tCNV to PINV,
especially at frontal sites, and the PINV was larger under
ambiguous than under clear matching conditions. Low-scoring
participants showed a right-sided predominance of the PINV,
which was absent in high-scoring participants. These results
resemble differences in the topography of the PINV between
healthy control participants and those with schizophrenia
under identical experimental conditions and suggest functional
differences between tCNV and PINV.