P300 under standard and surprise conditions in self-reported impulsive aggression

1. The purpose of the present study was to determine the cognitive psychoph ysiological correlates of impulsive aggression in a "high" functioning samp le: college students. 2. Visual P300 was measured during a standard oddball task and a surprise t ask that included unexpected low probability stimuli. 3. Results indicated significantly reduced P300 amplitude and prolonged lat ency for impulsive aggressive subjects to target stimuli on the standard ta sk. Target amplitude differences where further augmented under conditions i nvolving unexpected stimuli although no significant latency differences wer e observed. The topography of P300 amplitude to unexpected stimuli differed from that of the target. 4. Topographic group differences found for unexpected stimuli are suggestiv e of cognitive processing deficits previously demonstrated using neuropsych ological techniques in impulsive aggressive individuals.