Dmitriy Grigor'EVich Shaposhnikov

The purpose of the study is to examine gender differences associated with the mental pronunciation of words in EEG coherence patterns. Materials and Methods. The authors studied the impact of gender differences on the characteristics of EEG spatial synchronization patterns associated with the mental pronunciation of words denoting direction: up, down, left, right, forward, backward. The study enrolled 10 boys and 10 girls, aged 21±3. Results. The dominance of the left hemisphere was observed in young men, while the right hemisphere dominated in girls. Specific patterns of EEG coherence are formed in both left and right hemispheres. Discrimination of mentally pronounced words according to the EEG coherence values in young men is effectively implemented according to coherence patterns, which form separately in both left and right hemispheres, whereas in girls the coherence patterns of both hemispheres should be taken into account. Gender peculiarities in the structural and functional organization of the brain and the characteristics of its bioelectrical activity should not be underestimated, in particular, when developing a BCI based on EEG and inner speech. It is known that the internal (mental) pronunciation of words is reflected both in the cortical and superficially recorded bioelectrical activity of the brain. EEG recording of the activity has obvious advantages. However, so far little is known about manifestation of inner speech and its characteristics with respect to gender. Conclusion. The results obtained confirm gender differences in the EEG characteristics of the brain during the mental pronunciation of words denoting directions.

A linear discriminant analysis transformation-based approach to the classification of three different motor imagery types for brain–computer interfaces was considered. The study involved 16 conditionally healthy subjects (12 men, 4 women, mean age of 21.5 years). First, the search for subject-specific discriminative frequencies was conducted in the task of movement-related activity. This procedure was shown to increase the classification accuracy compared to the conditional common spatial pattern (CSP) algorithm, followed by a linear classifier considered as a baseline approach. In addition, an original approach to finding discriminative temporal segments for each motor imagery was tested. This led to a further increase in accuracy under the conditions of using Hjorth parameters and interchannel correlation coefficients as features calculated for the EEG segments. In particular, classification by the latter feature led to the best accuracy of 71.6%, averaged over all subjects (intrasubject classification), and, surprisingly, it also allowed us to obtain a comparable value of intersubject classification accuracy of 68%. Furthermore, scatter plots demonstrated that two out of three pairs of motor imagery were discriminated by the approach presented.

For many years, communicative interactions between people have been the subject of conceptual and heuristic consideration in the frameworks of the psychological and social sciences. About ten years ago, the study of communicative interactions began using the methods of experimental neurosciences. Until now research in this area has focused on the accumulation of various phenomenа and the development of methodology. Basic directions and perspectives of communicative interactions research by means of experimental neuroscience methods and mathematical modeling have been considered.