Mechanisms of Classification of Visual Objects in Children with Different Styles of Cognitive Activity

Abstract

A sample of seven-year-old children was divided into reflective and impulsive groups using the matching familiar figures test (MFFT). Event-related potentials of different regions of the cerebral cortex were studied in children from these groups performing classification of visual-object shapes on the basis of only one discriminative feature or with the use of additional information. Comparison of the success of visual-stimulus identification in reflective and impulsive children under the conditions of alternative choice (MFFT) and classification according to a specified discriminative feature demonstrates differences in the mechanisms of both selection and analysis of the sensory characters of the stimulus. When the shape of a visual object is classified according to the discriminative feature, the initial stages of analysis in impulsive children are accompanied by the emergence of wave N80 in the left hemisphere, which may reflect the higher rate of detection of the discriminative feature by these children. Impulsive children are also characterized by an earlier development and a higher amplitude of component P300 compared to reflective children. In the latter, waves N250 and N350, indicating continuing information processing, are superposed on this positive component. If the picture presented to children contains an element consistent with the discriminative feature, the N350 amplitude in the right temporo-parieto-occipital region and the negative shift corresponding to the N350 wave in the left temporo-parieto-occipital region are increased in reflective and impulsive children, respectively. Additional information increased wave N400 in the left frontal region.