Extraversion and arousal: Effects of attentional conditions on electrodermal activity

Abstract

Recent work has demonstrated that introverts show arousal decrements with increasing caffeine dosages under nonsignal conditions, but reverse this pattern under signal conditions. Other work, particularly in the areas of vigilance and memory, has pointed to greater attentiveness in introverts than extraverts. It was therefore hypothesized that the two groups would respond differentially under signal and nonsignal conditions as a function of attentional variations. The present study tested introverts and extraverts in a habituation paradigm involving systematic manipulation of signal and attentional conditions. Half of each personality group was randomly assigned to a distraction condition, the other half to an attending condition. Each S received two blocks of 19 habituation trials, a test stimulus and a dishabituation stimulus. In one of the two trial blocks, each stimulus was preceded by an auditory preparatory signal. Results showed that introverts gave larger SCRs, had higher SCLs, and showed greater dishabituation than extraverts. The signal reduced responding significantly more in introverts than in extraverts, and introverts were less affected by the distraction condition than were extraverts. Finally, extraverts showed more rapid habituation under nonsignal conditions and the signal produced a greater increase in habituation rate for introverts than for extraverts. Results were basically supportive of hypotheses derived from the Eysenck theory.