Intelligence related differences in induced brain activity during the performance of memory tasks

The aim of this study was to investigate the conflicting results in event-related desynchronization/synchronization (Pfurtscheller, 1999) in the upper alpha and theta bands related to intelligence. Two groups of individuals (high intelligent M-IQ = 128, and average intelligent M-IQ = 93), solved two memory tasks while their EEG was recorded. The data were analyzed with the ERD/ERS method and low resolution brain electromagnetic tomography (LORETA). In the upper alpha band high intelligent individuals displayed more desynchronization than did average intelligent individuals. In the theta band a minor but reverse effect was observed. The LORETA analysis indicated that average intelligent individuals displayed much higher signal to noise ratios (SNR) than did high intelligent individuals. The EEG source location for the high intelligent group was more anterior, whereas for the average intelligent group a more posterior EEG source location was observed. The findings were explained in the light of the neural efficiency model. (C) 2003 Elsevier Ltd. All rights reserved.