Correlation between EEG and cognitive abilities: sex differences.

EEG activity was recorded during rest in 9 male and 9 female volunteers, aged 23 and 27, from C3, C4, T3, T4, P3, P4, O1 and O2, referenced to the ipsilateral earlobe. In a separate session verbal, spatial and abstract reasoning subtests of the Differential Aptitude Test were administered. Samples of EEG activity of 20.48 s were analysed and the interhemispheric correlation was obtained. Interhemispheric correlation in the alpha band was significantly higher in women than in men at central, parietal and occipital derivations. Significant correlations were found between D.A.T. scores and interhemispheric correlation, positive for women with abstract and spatial aptitudes in the central cortex, and negative for men with spatial, abstract and verbal scores in most derivations recorded. The opposite sign of men and women's correlations suggests the existence of a different cerebral functional organization, women showing lower hemispheric differentiation than men.