INTROVERSION EXTROVERSION AND EVENT-RELATED POTENTIAL (ERP) - A TEST OF GRAY,J.A. THEORY

Following Gray's theory of introversion-extraversion, extraverts should demonstrate stronger reactions to stimuli of reward than to stimuli of punishment, while introverts should be more susceptible to stimuli of punishment than to stimuli of reward. In the present study reward and punishment were operationalized by winning and losing different amounts of money in a gambling situation while measuring Event-Related Potentials (ERPs) to the stimuli signalling winnings and losses and to the presentation of the amount to win or lose. The components P2, N2, and P3e of the ERPs to the feedback of winning and losing which are known to be influenced by stimulus meaning demonstrated the predicted interaction between extraversion and winning/losing. This interaction was found also for the late time region of the ERPs to the display of the amounts, according to winning or losing in the preceding trial. The results suggest that-on the background of an explicit theory-the ERP is a sensitive index for interindividual differences.