The error-related negativity (ERN) is a response-locked
brain potential generated when individuals make mistakes
during simple decision-making tasks. In the present study,
we examined ERN under conditions of reward and punishment,
among participants who scored extremely low or high on
the socialization scale of the California Psychological
Inventory (CPI). Participants completed a forced-choice
task, and were rewarded for correct responses in half the
trials, and punished for incorrect responses in the remaining
trials. A significant interaction between socialization
(SO) and condition revealed that low-SO participants produced
smaller ERNs during the punishment task than during the
reward task, whereas high-SO participants produced similar
ERNs in both conditions. Reaction time and electromyogram
data essentially bolster the interpretation that the ERN
effects reflect differences in error salience for high-SO
and low-SO participants, and are consistent with the
avoidance-learning deficits seen in psychopathy.