EVALUATION OF DYNAMICAL SYSTEMS OF THE BRAIN DURING VISUAL DYSFUNCTIONS ON THE BASIS OF THE KOLMOGOROV-SINAI ENTROPY

Abstract

The study of the effects of visual deprivation in humans, aimed at determining: structural peculiarities of different parts of the brain, character of their interconnections; participation of healthy cortex in processing stimuli of other modalities, was carried out. The examination by magnetic-resonance tomography proved that the brain is characterised by spontaneous fluctuations of activities in the state of quiet wakefulness, having spatial-ordered character in time dimension, which made it possible to separate rest-state network. However, principal structural similarity of basic rest-state networks in the blind and sighted people is noted.The aim of the research was to disclose peculiarities of the brain neurodynamics in case of vision dysfunctions of peripheral genesis under conditions of quiet wakefulness on the basis of Kolmogorov-Sinai entropy.220 subjects with congenital and acquired vision dysfunctions of peripheral genesis and 125 in fact healthy individuals with the normal vision from 8 to 20 years old were tested.Stable changes of Kolmogoron-Sinai entropy in case of vision dysfunctions in the state of quiet wakefulness with closed eyes, which are manifested in the period of the second childhood and adolescence, are as follows: 1) reduction of the level of randomness in the anterior-temporal cortical area in males with both congenital and acquired vision dysfunctions; 2) increase of the level of randomness in the central parts of convexital surface of the brain in females with acquired vision dysfunctions.The obtained results can be interpreted respectively as the state of increased auditory attention and enhancement of proprioceptive afferentiation processing.From the methodological point of view Kolmogorov-Sinai entropy can extend modern concepts as to the brain plasticity in case of vision deprivation in the context of the neurodynamic system evolution in time.