Extraversion-related differences in response organization: evidence from lateralized readiness potentials

Research utilizing a mental-chronometry approach to examine individual differences in extraversion suggests that extraversion-related individual differences may involve stimulus analysis, response organization, and peripheral motor processes. In a sample of 14 introverted and 14 extraverted female volunteers event-related potentials (ERP) and lateralized readiness potentials (LRPs) were recorded concurrently with reaction time (RT) measures as participants performed a two-choice go/no-go task. Although there were no extraversion-related differences in mean reaction time, introverts showed higher N1 amplitudes and shorter P3 latencies compared to extraverts. Furthermore, response-locked LRP latencies were reliably shorter for extraverts than for introverts. The latter finding provides first direct evidence for the contribution of central processes related to motor activation to account for extraversion-related individual differences. (C) 2003 Elsevier B.V. All rights reserved.