Gender differences in brain processes during inhibition of manual movements programs.

BACKGROUND: Motor response suppression can be regarded as an important aspect of the executive control, as a way of changing the behavioral pattern depending on the internal state or external factors. PURPOSE: The aim of our study was to examine whether there were differences in the ability of cortical inhibition of triggered motor program (in the context of the Stop-Signal task) between females and males. METHODS: We examined differences in the patterns of event-related EEG synchronization/desynchronization (ERS/ERD) in young volunteers under the conditions of complete inhibition of the triggered motor program of a manual movement. Thirty-six male and thirty-eight female (ages of 19 to 21) took part in the tests. The ERS and ERD indices were estimated within the EEG frequency range 8-35 Hz in frontal, central and parietal leads. RESULTS: In both gender groups, as a global pattern, the prevalence of connected phenomena with the EEG synchronization event in the range of α-activity of the EEG, apparently associated with inhibition of the running motor program was noted. CONCLUSION: Cortical electrical activity acquired certain specific features of the frequency-spatial organization, which could indicate the course of somewhat different brain processes of men and women.

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

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 ß2- 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.

Electrical Activity of the Cerebral Cortex during the Low-Frequency Acoustic Stimulation in Women with Different Characteristics of Alpha Rhythm.

BACKGROUND: Human functional capabilities, to a certain extent, depend on an individual's nervous system. The recording of the spontaneous electroencephalogram (EEG) makes it possible to estimate specific features of the nervous system, and in particular the activity of the human brain. PURPOSE: This study is aimed at investigating the brain in women with a high or a low individual α-frequency (ІαF), determined in a quiescent state during low-frequency acoustic stimulation. METHODS: The study group consisted of 113 right-handed healthy women in the age group 19-21 years. The study group was divided into 2 categories in terms of the average magnitude of ІαF - groups with high (n = 59, IαF ≥10.25 Hz) and low (n = 54, IαF ≤10.25 Hz) values of ІαF. The power and coherence of electrical activity of the cerebral cortex as well as the differences between the groups were evaluated in a quiescent state during low-frequency acoustic stimulation. RESULTS: In case of low-frequency acoustic stimulation, a high rate of EEG θ-, ß2-power, γ-waves in the cortex, α1-oscillations - in frontal areas were registered in women with a high α-frequency, while the power α2-, α3- and ß1-activity became lower in the cortex. Women with a low α-frequency had a decrease of the cerebral cortex α-θ-, α- and ß-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.