Developmental changes in the mechanisms of image classification in young schoolchildren with different cognitive styles

Abstract

Investigation of developmental characteristics of visual recognition at the elementary school age provides information on the structural and functional brain reorganization underlying the features of cognitive activity of a child at this ontogenetic stage. The elementary school age is an important stage in the development of the nervous system. Further maturation of cortical neuronal structures takes place between 7-8 and 9-10 years of age. Developmental changes in cyto-and fibroarchitecture, as well as in the organization of neural assemblies in the visual cortex, have been demonstrated to coincide with this age period [1][2][3]. Structural and functional maturation of the cortex, which is reflected in characteristics of the spatial synchronization of EEG rhythms, testifies to a rather high level of the brain functional organization at the end of the elementary school period [4]. This maturation determines the perfection of the visual perception system in the ontogeny of a child. There is evidence of changes in the amplitude and temporal parameters of individual components of evoked potentials. The latency of the P 1 early component (110-120 ms) does not change from 7-8 years to adulthood, but its amplitude substantially decreases with age; the latency of the N 2 component drops from 300 ms at the age of 7-8 to 250 ms at the age of 9-10 years [5,6]. A developmental decrease has also been revealed in the P 3 latency (600 ms at the age of 7-8 and 350 ms at the age of 11-12 years) [5][6][7][8]. The longer latency of the P 350 component in children is determined by the functional immaturity of cortical neural networks. It can be suggested that systems responsible for different stages of information processing mature heterochronously.Complication of the functional organization of visual perception is reflected in an increase in the regional specificity of components of event-related potentials (ERPs) and a dependence of their amplitude in different cortical areas on the cognitive task.It has been shown that, under conditions of quiet viewing, cortical areas are distinctly specialized at the initial stage of the analysis of a visual stimulus in 7-year-old children as distinct from younger children [9,10]. The operation of detecting contrasting edges (presentation of a checkerboard pattern) evokes the greatest changes in the P 130 components of ERPs in the visual projection area, whereas the temporo-parieto-occipital area is specifically reactive to presentation of intricate stimuli (faces or geometric figures). However, at the age of 9-10, the specific involvement of the temporo-parieto-occipital area into the analysis of intricate stimuli is not always the case and is not reflected significantly in the ERP parameters averaged over a group. This fact can be explained by different circumstances, for example, by increasing interindividual differences in the ERP by this age [9].Detection of individual features of age-related changes in the mechanisms of visual recognition is of great importance for an individual approach...