SENSITIVITY TO CONDITIONED OR UNCONDITIONED STIMULI - WHAT IS THE MECHANISM UNDERLYING PASSIVE-AVOIDANCE DEFICITS IN EXTROVERTS

The most important discrepancy between Gray's (1981) and Newman's (198 7) approaches to passive avoidance was based on the role played by the Behavioral Inhibition System (BIS): Gray, but not Newman, predicted t hat passive avoidance deficits could be mediated by an underactive BIS and hence that these deficits could be found in strictly aversive con texts. Two different studies have been conducted to investigate these issues. In the first, two versions (one involving reward and punishmen t and the second punishment only) of the successive go/no go discrimin ation task used by Newman, Widom, and Nathan (1985) were administered to groups classified according to extraversion and neuroticism. Result s, in accordance with Newman's hypotheses, showed more passive avoidan ce and less omission errors in (neurotic) extraverts as compared to (s table) introverts in mixed incentive contexts. In addition, consistent with Gray's model, more passive avoidance and less omission errors we re also found in stable extraverts as compared to neurotic introverts in solely aversive contexts. In Study 2, multiple choice exams were us ed considering each question an approach-avoidance conflict (similar i n some aspects to the reward-punishment task in Study I). Once effects of knowledge were controlled, extraverts had a greater tendency to ap proach than introverts in these exams. Finally, a third study confirme d that passive avoidance errors both in the reward-and-punishment Task of Study 1 and in multiple choice exams were correlated. Different me chanisms lending to disinhibition in extraverts that are dependent on the functioning of both the BIS and the Behavioral Activation System ( BAS) and the contribution of sensitivity to unconditioned and conditio ned stimuli are discussed. (C) 1995 Academic Press, Inc.