Event-related brain potentials (ERPs) were recorded in an S1-S2 paradi
gm. S1 was a warning signal that indicated whether subjects had to res
pond as quickly as possible, or had to delay their responses until 1 s
ec 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 betwee
n groups differing in negative affectivity, positive affectivity, sens
ation seeking, and impulsivity. Persons scoring high on sensation seek
ing (SS) showed larger NSW amplitudes than low-scorers on SS. This fin
ding is interpreted as suggesting that larger NSW amplitudes reflect e
motions that were approach-related rather than avoidance-related. It i
s suggested that mechanisms generating the NSW are influenced by the a
ffective characteristics of S1.