Gender Differences in Hemispheric Spatiotemporal EEG Patterns upon Reproduction of Verbal Information

Abstract

Changes in EEG power and coherence were studied in ten men and ten women during mental reproduction of dichotically presented lists of words. The EEG was recorded with 14 electrodes located over symmetric points of the left and right hemispheres. In all subjects, the mental reproduction was accompanied by an increase in the power of the θ1 rhythm in the frontal regions and a decrease in the power of the α1 and α2 rhythms in the caudal regions of the hemispheres. A decrease in the power of the θ2 rhythm in the caudal regions of the hemispheres was greater in women than in men. Gender differences were also observed in the left- and right-hemispheric coherence reactivity. During word reproduction, men showed a higher EEG coherence in the θ2 band in the right hemisphere, while women displayed a greater increase in the coherence of the α1 and α2 rhythms in the left hemisphere. Lateral differences in reactivity of the intrahemispheric coherence in these frequency bands were observed only in women and were caused by a decrease in coherent interactions in the right hemisphere and their increase in the left hemisphere. These gender differences can be associated with different strategies of information memorization: men involve predominantly episodic memory, and women use semantic polymodal encoding.