The work of S. N. Rayeva' contains much useful information about man's subcortical nerve networks obtained by study during the neurosurgical operations on the patients having an injury in motor activity. The peculiarities of the thalamic nerve networks and extrapyramidal system were examined to functionally identify and to clear up the neuronal mechanisms determined by a tremor of the patients suffering by parkinsonism. The author had described early unknown factors in man's brain activity that consisted in a phenomenon of the outstripping processes, correlating with the intensity of the arbitrary attention accompanying the arbitrary movements.
The book of V. B. Shvyrkov* is devoted to the analysis of the behavior mechanisms using the functional system theory of P. K. Anokhin. The necessity of system approach to the study of the problem is emphasized. The neuron mechanisms providing the simple behavioral acts were considered as an example of the information exchange between the appropriate nerve networks and surroundings. The mechanisms of including of the nerve networks into behavior system acts were considered. Relation between mental and neurophysiological processes during the behavioral act was studied.*
The facts of selective responses of nerve units of the rostra1 cortical areas on stimuli having different significant role have been described in the paper of A. S. B a t ~e v . ~ Authors have shown that the nerve networks of sensory cortex selectively respond to biologically meaning features of a stimulus . 3 In experiments on the invertebrate neurons, E. N. Sokolov and T. N. Gretchenko have discovered different types of cell plasticity: (1) local plasticity of the chemoreceptor membranes in the form of the appropriate dynamics of the mediator potential, (2) selective plasticity of the pacemaker potential, and (3) plasticity of the chemoreceptor areas of the neuron forming by the action potentials evoked by the electrical stimulation. Their role in nerve networks activity has been discussed.
By microelectrode studies of the various levels of the tactile analyzer,