Bioelectric brain activity during visual perception of verbalized and nonverbalized stimuli in seven-to eight-year-old schoolchildren

Abstract

Neurophysiological mechanisms of visual perception of verbalized and nonverbalized stimuli have been studied in girls (n = 89) and boys (n = 109) aged seven to eight years. It has been shown that, in children of this age, neurophysiological mechanisms of the visual perception system during the selection of verbalized and nonverbalized stimuli have similar organizations of functional rearrangements and are characterized by the general involvement of cortical areas and by the lack of clear specialization of the cerebral hemispheres. However, the choice of nonverbalized visual stimuli is characterized by a more pronounced generalization of the functional interaction between cortical areas and by the increased spectral power of the EEG’s high-frequency components in anterior associative areas. The increased spatial synchronization in the EEG θ- and β 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 the neurophysiological mechanisms of visual perception in boys and girls have been detected. Spatial and temporal organizations of bioelectric activity (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 to the left hemisphere. In boys perceiving verbalized and nonverbalized visual stimuli, a greater contribution of posterocentral cortical areas has been observed. The detected differences are considered to reflect a greater maturity of identification mechanisms in girls aged seven to eight years as compared to boys.