[Neurophysiologic mechanisms of the change in visual perception in children between 3 and 7 years of age]

Abstract

Analysis of evoked potentials (EP) to visual images (a homogenous square, a checker-board and a schematic image of a face) has revealed one and the same type EP configuration and reactivity in the projection and posterior associative areas in three to four year old children. Six to seven year old children have exhibited a specialization of cortical areas involvement in the analysis of visual stimuli of different complexity, as manifested in the predominant reactivity of the projection and anterocentral areas in response to presentiation of the checker-board and of the temporo-parieto-occipital zone in response to the face image. Characteristics of involvement of different areas in the analysis of visual stimuli are compared with reaction time and the "time of central processing" in the course of elaboration of a reaction of choice of images out of various number of alternatives. The dynamics of such characteristics in three to four and six to seven year old children is the same in the choice of easily recognizable checker-board and familiar (face) images and does not coincide at the presentation of probabilistic textures: their differentation is readily achieved only by children of senior age. It is assumed that the nature of involvement of different areas in the reaction to complex visual stimuli accounts for the characteristics of visual perception at different stages of individual development.