[Formation of rhythmic processes in the bioelectrical activity of the cerebral cortex]

On the basis of simple ideas of the cerebral cortex as a distributed mass of interconnected excitatory and inhibitory cells the differential equation describing electroencephalogram (EEG) and determining the rhythmic processes in the cortex was derived and analysed. It was proposed a common mechanism explaining a wide complex of electrophysiological phenomena: phylogenetic and ontogenetic differences in the EEG, various electroencephalographic reactions such as arousal reaction in animals, reaction of alpha-rhythm depression in humans, driving EEG reaction, evoked potentials and cell reactions on short stimuli. The reasons for profound shifts in the EEG rhythms upon changes of functional states of the cortex, for example transition from sleep to awakeness and vice versa, and for such phenomena as shortening of apparent inhibitory phase in cell reactions and evoked potentials upon general activation of the cortex are discussed.