Resting State EEG as an Indicator of Cognitive Training Effect in Older Adults

Although there are common principles that can be demonstrated in cognitive aging, enormous variability exists across individuals. Among other factors inter-individual variability is attributable to involvement in mental activity. The purpose of this study is to outline the changes of resting state EEG in aged men and women associated with difference in intellectual environment of their professional activity. Elderly (age 63.8, N=112) scientists (SA) and people unrelated to professional scientific activity (NSA) participated in the study. All subjects were employed full time. EEG was recorded from 26 symmetrical regions of the hemispheres in a states with closed and with open eyes. Power spectral density was calculated in delta, theta, alpha 1, 2, 3, beta 1, 2 and gamma frequency ranges. The bandwidths for the frequency bands were defined using individual alpha peak frequency as the anchor point. In condition with closed eyes, ANOVA revealed significant gender × frequency band × region × group (SA, NSA) interaction. Testing of interaction demonstrated effects in alpha 2, 3 rhythms power characterized by opposite changes of antero-posterior spectral power gradients in SA and NSA groups of men and women. There was no difference between SA and NSA groups in frontal power density. Among women members of SA group had lower posterior power than those of NSA group. In eyes open condition, significant asymmetry due to higher power values in right in comparison with left hemisphere in frontal region was found in SA group. Asymmetry of power values was not revealed in NSA.