No abstract

A test group consisting of 113 right-hand healthy women from the ages of 19 to 21 was divided into two groups according to the average magnitude of their individual modal αfrequency -groups with high and low values of individual modal αfrequency. The ideal time of a simple sensorimotor reaction and choice-point behavior as well as speed capabilities of nervous processes during the tapping test, and measures of the coherence of EEG frequency components individually determined for each testee in quiescent intervals and while performing alternative movements by the right hand fingers were evaluated. Women with high modal α-frequency had better speed capabilities of nervous processes. Women with a high IαF had a less time of simple and complex reactions. The increase of coherence coefficients was seen throughout the EEG frequency spectrum in women performing alternate movements by fingers. Alternate movements of fingers performed by women with low α-frequency are provided by even higher frequency coherence of the EEG components in frontal, anterior temporal and central areas and by much lower frequency in the posterior temporal and parietal-occipital cortex areas compared to testees with high α-frequency.Formulation of scientific problem and its significance. Movements by the upper extremities, particularly but not exclusively, by human fingers, form the basis of the manual movements in any labor activities. This or that person's individual functional capacities of the motor system acquire the critical score for a successful learning of a wide range of trades in the present-day society. For this purpose, an academic community places greater emphasis on issues dealing with the personality traits of the cerebral processes guaranteeing the motorial programming of the manipulation movements (MM).Analysis of studies of the problem. Various aspects of the abovementioned problem were studied in the area of neurophysiology concerning motor activities [1][2][3][4][5][6][7][8]. MM are obviously associated with the significant alterations of the brain activities ensuring the formation of the appropriate motor programs and orders. However, any specific information concerning these processes in the cerebral cortex is still very limited. It is not improbable that certain performance measures of the cerebration being correlated with MM -their amplitude, speed and accuracy are existed.Scientists [9][10][11][12] found out that individual values of the amplitude-frequency characteristics of any α-rhythm, including the modal frequency of such a rhythm demonstrate a significant informational content in determining the state of the main physiological functions of the man. According to the data of Bazanova [9], Kristeva, Charakov, Losch et al. [12] the ideal coordination of processes organizing movements and capacity for the censorship are positively correlated to the power of the individual EEG αrange and negatively to the tension of the muscles of the facial expression (forehead) being inactive during the MM autocinesia. These statement...

Background: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. Purpose: 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. Methods: 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. Results: 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. Conclusion: 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.

cortex, α1-oscillations -in frontal areas were registered in women with a high α-frequency, while the power α2-, α3-and β1-activity became lower in the cortex. Women with a low α-frequency had a decrease of the cerebral cortex α-θ-, α-and β-activity. This was recorded as more generalized, and the expression of γ-waves was more localized. All the participants had increased values of coherence of the EEG frequency components in the cortex. Some overexertion on the right side was detected in the right hemisphere posterior structures. Some local reduction of the coherence of θ-, α1-, α3-oscillations was found in women with a high α-frequency and α1-activity among the study group members with a low α-frequency in the frontal and anterior temporal areas. Conclusion: The establishment of common factors in the study group is an important step towards defining clear prognostic criteria for the physiological capabilities of people based on the congenital features of brain function.

Cortical activity during inger movements...