Personality effects on brain potentials in an S1-S2 paradigm

Event-related brain potentials (ERPs) were recorded in an S1-S2 paradigm. S1 was a warning signal that indicated whether subjects had to respond as quickly as possible, or had to delay their responses until 1 sec after S2. The amplitudes of the frontal N1, the negative slow wave (NSW) and the terminal contingent negative variation (CNV) were larger following the speed-instruction than after the delay-instruction. To investigate the influence of personality, comparisons were made between groups differing in negative affectivity, positive affectivity, sensation seeking, and impulsivity. Persons scoring high on sensation seeking (SS) showed larger NSW amplitudes than low-scorers on SS. This finding is interpreted as suggesting that larger NSW amplitudes reflects emotions that were approach-related rather than avoidance-related. It is suggested that mechanisms generating the NSW are influenced by the affective characteristics of S1.