[Effect of emotional tension on the spatial-temporal organization of prestimulus potentials of the neocortex of a human operator on the recognition of a meaningful photic stimulus]. / Vliianie émotsional'nogo napriazheniia na prostranstvenno-vremennuiu organizatsiiu predstimul'nykh potentsialov neokorteksa cheloveka-operatora pri opoznanii znachimogo svetovogo stimula.

Analysis of psychometric data at recognition of digital stimuli in a state of high emotional stress allowed to single out two groups of subjects--with improved and with worsened quality of activity. It is shown that the structure of intrahemispheric cross-correlation coefficients before states with a short time of recognition, a long time and with nonrecognition of the stimulus, appearing in operative quietness, is preserved in emotional stress for subjects with a better quality of activity and changes for half of the pairs of intrahemispheric leads in subjects with worsened quality of activity.

[Parameters of the prestimulation EEG during operator recognition of a meaningful photic stimulus]. / Parametry predstimul'nykh EEG pri opoznanii operatorom znachimogo svetovogo stimula.

Comparison of prestimulus EEG parameters with characteristics of recognition of a numeral stimulus showed that the complex of spatial-temporal parameters of the EEG of the operator reflects both the rate of success of the given activity and its quality. Functional state of CNS previous to optimal recognition (70% of efficiency, short reaction time), are characterized by mean level of spatial synchroneity of potentials in both cerebral hemispheres and by mean expressiveness of frequencies from 0.2 to 30 Hz in electrical activity of the majority of studied neocortical areas as compared with the states before recognition with prolonged reaction time and before non-recognition of the stimulus.

[Relation between "rest-activity" behavioral phases and features of the spatial organization of cortical potentials in experimental neuroses]. / Sootnoshenie povedencheskikh faz "pokoi--aktivnost"' i kharakteristiki prostranstvennoi organizatsii potentsialov kory pri éksperimental'nom nevroze.

The development of experimental neurosis in rabbits led to stable changes in the correlation between behavioural phases in "rest-activity", i.e. some prolongation of active phases and a considerable shortening of rest phases. The analysis of spatio-temporal organization of cortical potentials by comparing successive topograms showed that changes occurred not only in quantitative parameters of rest-activity phases but also in their qualitative characteristics. Thus the depth of the resting states in neurosis lessened and the spatio-temporal cortical potentials' characteristics during the active phases were disorganized. The described shifts in the cortex state probably hindered normal alternation of activity-rest behavioural phases providing for optimal conditions of animals' activity.

Investigation of the functional role of the septum.

A spectral-correlation analysis was made of the EEG recorded from the motor and visual cortex, hippocampus, and septum (in some series of experiments, the lateral geniculate body and mesencephalic reticular formation also) of rabbits in the presence or absence (background) of sensory stimulation. To investigate the functional role of the septum as a pacemaker the method of "rhythm binding" by electrical stimulation of the septum (lateral and medial nuclei) was used. By electrical stimulation of the medial nucleus of the septum at a frequency of 4-30 Hz rhythm binding was successfully obtained in all regions studied. Maximal rhythm binding was observed in cortical potentials. It is postulated that cortical rhythmic activity is generated as a result of physiological interaction between cortex and septum.

[The effect of low-frequency stimulation of the diencephalon on the topogram of cortical potentials in freely moving rabbits]. / Vliianie nizkochastotnogo razdrazheniia promezhutochnogo mozga na topogrammy potentsialov kory u svobodno peredvigaiuschiksia krolikov

The spatio-temporal organization of the cortical potentials in rabbits was investigated by means of comparison of successive electroencephalotopograms. This systemic organization was characterized by the potentials' sagittal gradient and its inversion within the 4-6/sec range due to higher amplitudes in the frontal cortical areas, - during natural transition from the active to passive behavior as well as after low-frequency stimulation of the thalamic midline nuclei and of the hypothalamic supraoptic area. Single stimuli applied to the structures under study ordinarily prevented any obvious active behavioral periods, although entailed no long-lasting changes in the rest-activity dynamics.

[The functional role of the septum]. / Issledovanie funktsional'nogo znacheniia peregorodki

A study of the electrical activity (background and at sensory stimulation) of the motor and visual areas of the cortex, hippocampus, septum (in some cases the lateral geniculate body and the midbrain reticular formation) was carried out on rabbits by the method of spectral-correlation analysis. The method of driving reactions to electrical stimulation of the lateral and medial nuclei of the septum was used to investigate its functional role as a pace-maker. The spectograms of all the analyzed areas of the brain showed the presence of acquired rhythms during electrical stimulation at 4-30 Hz. The acquired rhythm was most prominent in cortical potentials. It is assumed that the generation of rhythmical cortical activity is due to physiological interaction of the cortex and septum.

[The mechanism of action of a reinforcing stimulus]. / K voprosu o mekhanizme deistviia podkrepliaiushchego stimula

Experiments on alert non-immobilized rabbits revealed that electrical cutaneous stimulation of a limb, used as a reinforcing agent in elaboration of a conditioned reflex to photic flashes, weakened slow polyrhythmic oscillations of background EEG and late components of evoked potentials in the visual cortex to photic flashes. Against this background, the connection between slow potentials and spike activity in both the visual and sensorimotor cortical areas considerably diminished. During EEG activation, induced by the reinforcing stimulus, inhibitory pauses and post-inhibitory activation in the firing of the neocortical units weakened and protracted, ordered spike activity appeared. The data obtained are in agreement with the hypothesis that weakening of the recurrent inhibition system is one of the basic mechanisms in the action of the reinforcing stimulus in conditioning.