Brain function and higher nervous activity

Some actual problems of higher nervous activity have been analysed on the peculiarities of brain states in the course of different types of conditioning and reactivity of the nervous structures which depend on the brain state have been considered. A concept of brain state as a specific mechanism of each temporal connection forming during the learning process has been formulated for the first time. The authors suggest that the brain represents the dynamic system with changeable structure which reveals itself in multitude nervous set constellation during various types of activity. This concept is presented to be the theoretical basis for integral evaluation of functional capacities of central nervous system.     

Comparative pathology of higher nervous activity

In experiments with defensive behaviour, using multiparametric recording of indices, studies have been made on the origin and development of pathological disturbances in the higher nervous activity of insectivores, carnivores and primates during presentation of difficult conditioned reflex problems or extreme stimulation. It was found that elaboration of absolute differentiation retarded conditioned reactions with a delay of 25 s in insectivores is a difficult task which results in pathological changes in the higher nervous activity. In hedgehogs, neurotic changes are immediate, all the investigated indices being affected. In carnivores, especially in primates, the onset of evident pathological changes is preceded by a long preneurotic period, i.e. a stage of self-regulation. In pathological process, more corticalized forms of the nervous activity are initially involved. Common features and differences in the development of pathological changes in the higher nervous activity among mammals are discussed.     

Feedback and the typological characteristics of higher nervous activity]

Apparatus of the theory of automatic regulation and control systems is applied for explanation of typological characteristics of the higher nervous activity. On the basis of the analysis of activity of four types of automatic control systems a hypothesis is suggested that these characteristics are connected with organization of the feedback in the functional system, and analogies drawn between the types of the higher nervous activity and types of automatic systems.     

The cognitive set and problems of the human higher nervous activity

Two kinds of cognitive sets for verbal and non-verbal stimuli were revealed in healthy subjects: an "intellectual blindness" and a distortion of perception and assessment of the stimuli size. Analysis of the response time to a probe stimulus and a spectral analysis of the cortical EEG revealed a participation of these sets in cortical functions: a stable set organizes and improves the stimuli perception and assessment but impedes this process in a modified situation. An optimal balance between the two sets seems to be necessary for effective cognitive activity.