Bioelectrical activity of the brain during performance of manipulative movements in women with different modal alpha-frequencies

Abstract

An important component of the general biological problem of coordinated activity of the brain’s motor systems and of the executive apparatus during the implementation of motor functions is the question of the interconnection of electroencephalogram (EEG) rhythm characteristics, above all α-rhythm, with control peculiarities of manipulative movements (MM). A test group consisting of 113 healthy right-handed women from the ages of 19 to 21 was divided into two groups according to the average magnitude of their individual modal α-frequency – groups with high and low values of individual modal α-frequency (IαF). The ideal time of a simple sensorimotor reaction and choice-point behavior as well as speed capabilities of nervous processes during the finger tapping test, and measures of the power spectrum of ЕЕG spectral components individually determined for each testee in quiescent intervals and while performing alternating movements by the fingers of the right hand were evaluated. Alternate female finger movements were accompanied by a decrease in the EEG α2- and α3-activities in the posterior cortical areas, and β1- and γ-activities in the frontal, temporal and central areas of the cortex compared with the same in the immobile state; they were also characterized by the generalized growth of θ-oscillations and local (in the frontal leads) – α1- and β2-activities. Thus, in both groups of women surveyed the increase in activity of those cortical structures that ensure its implementation – sensory perception, motor start and motor programming commands and sense-motor coordination, was found. When MM are performed by women with a higher output α-frequency, they were characterized by more local changes in the electrical activity of the cerebral cortex. People with a lower modal α-frequency were characterized by somewhat less specific and differentiated features of the cortex activation. Alternating movements of fingers performed by women with low IαF were associated with higher EEG θ-, α1-, α2-activities, generally in the cortex, and α3-, β- and γ-oscillations – in the posterior areas than in those with high IαF. Instead of this, a relatively lower power spectral EEG was recorded in the frontal leads of the range consisting of α3-, β- and γ-oscillations. Intergroup differences found by us may indicate a higher status regarding a specific cortical tone, its readiness for activity and control of information processes in people with high IαF in comparison with those who had low IαF. It is natural that different levels of features of such activation systems achieve specific outcomes in testees with a different starting IαF. Women with a higher IαF had better speed characteristics of nervous processes.