[Relations between two types of the spatial-temporal organization of the human brain potentials during formation and actualization of set to a visual nonverbal stimulus].

The functional state of the brain cortex estimated by the dynamic changes in the global spatio-temporal organization of brain potentials (STOP) was studied at different stages of the cognitive set formed on the basis of the image of two circles of different diameter. Thirty five subjects (predominantly, right-handed) were examined. The method of quantitative estimation of successive topograms was used for the analysis of the STOP. Two coexisting types of the STOP were described. The relations between them define the functional state of the brain. Quantitative characteristic of these relations is reflected in the value of the coefficient of dynamic variation (CDV). Group of subjects with the stable and unstable set had significantly different values of CDV during the experiment. These groups of subjects also had different topographic characteristics of the CDV.