ON THE PROBLEM OF CORTICAL ACTIVATION - T HE ROLE OF CERTAINTY UNCERTAINTY OF SITUATION

Ontogenetic data concerning EEG correlates of activation during attent ion were analysed in various paradigms. The results were compared with the degree of certainty/uncertainty of situation established by the i nstruction or determined by the subject. A proposition is made about t wo activation types in human EEG desynchronization and synchronization within the alpha-band Both activation types which facilitate brain or ganization of present or forthcoming activity realize it in their own ways. Desynchronization which leads to disintegration of the system pr omotes formation of the new one. Synchronization immediately facilitat es functional integration of brain structures involved into a specific form of activity. The results of processing and evaluation of informa tion which characterize certainty/uncertainty of situation determine t he balance between the two activation types.