INTELLIGENCE, REACTION-TIME, AND EVENT-RELATED POTENTIALS

Event-related potentials and reaction time (RT) were recorded concurrently during the performance of six simple cognitive tasks for subjects (N = 30) who varied in mental ability. P300 latency to the target stimulus increased with increasing task difficulty in the same manner as RT on these tasks. P300 latency to the target stimulus was inversely related to mental ability, particularly for the more difficult paired-stimuli tasks. The first unrotated factor extracted from the intercorrelation of P300 latency to the target stimuli on these tasks defined a general P300 latency factor that accounted for 41% of the variance. The P300 latency factor scores were inversely related to general intelligence factor scores, (-.36, p < .05). The relationship between P300 latency and RT as distinguished from movement time, was negligible. These results suggest that P300 latency and RT may assess the stimulus-evaluation time and response-production time components of cognitive information processing, respectively, that vary inversely with general intelligence.