RELATIONSHIP BETWEEN THE BRAIN-STEM AUDITORY-EVOKED RESPONSE AND EXTROVERSION, IMPULSIVITY, AND SOCIABILITY

It has been suggested that the trait of extraversion is associated wit h physiological arousal (Eysenck, 1967). Both psychophysiological and behavioral studies have generally supported this statement (Eysenck & Eysenck, 1985), However, recent research has suggested that the trait of impulsivity is the trait most closely linked to the physiological a rousal mechanisms believed to underlie extraversion (Revelle, Humphrey s, Simon, & Gilliland, 1980). This study utilized brainstem auditory e voked responses (ABRs) to investigate which trait (extraversion, impul sivity, sociability) is most closely related to hypothesized ascending reticular activating system-regulated arousal processes. The results indicated that the full scale of extraversion was related to ABR wave V activity, r = .27, p < .025, with extraverts exhibiting slower ABR l atencies compared to introverts. Analyses of the subscales indicated t hat sociability (r = .27, p < .025), rather than impulsivity (r = .05, p < .70), contributed more to this effect. (C) 1998 Academic Press.