Extraversion and inhibition: a slow-potential study

This report presents data showing that extroverts (Eysenck Personality Inventory) develop larger positive vertex slow potentials than introverts under extinction conditions ("no go" instruction in a fixed foreperiod reaction time task). The effect was clearer in subjects with low neuroticism (N) scores than in those with a middle N level. Since independent evidence indicates that cortical positivity is associated with inhibitory phenomena, results are interpreted as lending support to the notion that extroverts may develop more inhibitory potential than introverts under certain conditions.