The Electrical Brain Activity in Men with Different Alpha-Rhythm Characteristics during Manual Movements Executed by...

The ability to control motor actions and flexibly interact with the environment is considered one of the main components of the human brain executive functions. The spontaneous electroencephalogram (EEG) is among the physiological techniques making it possible to formulate a direct estimation of specific features of the activity of the human brain during manual movements.

This study is devoted to an investigation of brain processes in men with a high or a low individual α-frequency determined during manual movements executed by the subdominant hand.

A test group consisting of 104 right-handed healthy men from the ages of 19 to 21 was divided into 2 groups in terms of the average magnitude of their individual α-frequency (ІαF) - groups with high (n = 53, IαF ≥10.04 Hz) and low (n = 51, IαF ≤10.04 Hz) values of ІαF. The power and coherence of the electrical activity of the cerebral cortex as well as the differences between the groups were evaluated by the testees during manual movements executed by the subdominant hand.

Manual movements executed by the subdominant hand in response to the sensory signals are generally accompanied by the increased coherence of the EEG frequency components, especially, in the frontal, anterior temporal and central brain regions in men with different α-activity characteristics. Under these conditions, it has been found some electrogenesis power lowering in the cortical areas responsible for the sensory analysis, motor programming, sensory and motor information integration. Such changes have been combined with the local power increase of θ-, α1-oscillations in the frontal leads. Additionally, men with a low IαF were characterized by the local growth of α3-activity in the frontal areas of their cortex. Men from both groups also had the generalized increase in the capacity of the high-frequency β2- and γ-oscillations. Some higher power and coherence of the EEG frequency components have been registered in men with the low IαF in comparison with men having some high α-frequency.

The functional content of the established differences may generally reflect some relatively lower tone of the cortex activation in men with a low IαF and can be specifically compensated by some increased "intensity" and the redundancy of brain processes.