[Bioelectrical brain activity during visual perception of verbalized and non-verbalized stimuli in 7-8 year-old schoolchildren]

Neurophysiological mechanisms of visual perception of verbalized and non-verbalized stimuli have been studied in girls (n = 89) and boys (n = 109) aged 7-8 years. It has been shown that in children of this age neurophysiological mechanisms of the visual perception system during choosing verbalized and non-verbalized stimuli have a similar organization of functional rearrangements and are characterized by generalized involvement of cortical areas and by the lack of clear specialization of the cerebral hemispheres. However, the choice of non-verbalized visual stimuli is characterized by a more pronounced generalization of the functional interaction between cortical areas and by an increased spectral power of EEG high-frequency components in anterior associative areas. The increased spatial synchronization in EEG theta and beta bands in the frontal areas emphasizes the contribution of these structures to the analysis and processing of visual stimuli at this stage of development. Differences in neurophysiological mechanisms of visual perception in boys and girls have been detected. Spatial and temporal organization of BEA of the brain in girls performing visual tasks is characterized by a stronger and more varied ipsi- and contralateral statistical relationships in the fronto-occipital direction and displacement of interaction centers into the left hemisphere. In boys perceiving verbalized and non-verbalized visual stimuli a greater contribution of postcentral cortical areas has been observed. The detected differences are regarded as reflecting a greater maturity of identification mechanisms in girls aged 7-8 years as compared to boys.