INTELLIGENCE AND SPATIOTEMPORAL PATTERNS OF EVENT-RELATED DESYNCHRONIZATION (ERD)

Recently, several studies have reported negative associations between brain activity under cognitive load and psychometric intelligence. The positron emission tomography (PET) used in these studies allows a high spatial resolution, but it does not permit an assessment of the temporal course of cerebral activation. Therefore, this study examined the relationship between psychometric intelligence (determined by Raven's Advanced Progressive Matrices) and spatiotemporal patterns of cortical activation. Seventeen university students performed an elementary cognitive task, the Sentence Verification Test (SVT), during which the electroencephalogram (EEG) was recorded. In the EEG, the event-related desynchronization (ERD) was quantified, which can be interpreted as a correlate of cortical activation. Lower IQ participants displayed a comparatively unspecific cortical activation increasing with time, whereas higher IQ participants were characterized by a temporal development of activation in those cortical regions that are required for task performance, resulting in less overall activation as compared to the lower IQ participants. These findings support the hypothesis of a more efficient use of the brain in higher IQ individuals.