The role of the lateral and medial hypothalamus in reproducing food and escape instrumental reactions]

In experiments on two dogs it has been found that testing electric stimulation of the lateral hypothalamus reproduces instrumental movement in case of elaborated alimentary instrumental conditioned reflexes (CR) to a tone and does not reproduce it at elaborated acid-defensive instrumental CR. Under testing electric stimulation of the medial hypothalamus the instrumental movement practically is not reproduced neither in alimentary nor in defensive situation. Appearance of instrumental movement at LH electro-stimulation in alimentary situation is connected with activation of backward conditioned connection from motivation "alimentary" LH centre to representation of this movement in the motor cortex.     

The latent period of a conditioned motor reaction in dogs and cats]

A study was made of the temporal characteristics of motor reactions in cats and dogs to an instantaneous change in the shape of a photic signal. The latency value is an individual characteristic of the animal; it undergoes only slight fluctuations on different experimental days. No influence has been found of the intersignal interval magnitude (8--70 sec) on the duration of latencies. Longer experiment (about 300 signals in three hours) leads to longer latencies and their greater variability.     

A computer analysis of EEG intersignal reactions during the the acquisition of conditioned motor-food reflexes in dogs]

Background electric activity was studied of different neocortex areas in interstimulus intervals at the stage of generalization during elaboration of motor alimentary conditioned reflexes in dogs. For this stage the appearance is typical of short-term (0.1-0.3 s) packs of high frequencies (above 40 osc./s) significantly exceeding the adjacent initial background by frequency and amplitude (along side with motor interstimulus reactions). The index of specific variation, elaborated by us, allowed to single out this EEG pattern in the initial realizations of the background activity during their input in the computer. With the purpose of further evaluation of the above phenomenon parameters non-standard approaches of computer analyses were used, directed to decomposition of the EEG curve into the system of oscillations and receipt of corresponding amplitudes frequencies distributions (maps). It was shown, the described high frequencies packs were localized on these maps in definite sufficiently compact places.     

The evolutionary aspects of the dynamic acquisition of simple conditioned reflexes

The dynamics of elaboration of simple classical and instrumental conditioned reflexes in snails, rats, cars, dogs and humans was investigated. The dependence between the number of correct responses (in percentages) and the number of reinforcements was significantly approximated with exponential equation including the coefficient describing the initial level of conditioning. Regression analysis gave the opportunity to compare the dynamics of conditioning in different animal species.     

The role of trace excitatory processes in the formation of conditioned reflexes to time]

I. P. Pavlov's hypothesis on the role of trace excitation in conditioning to time was verified by mathematical methods proceeding from experimental data on elaborating in rabbits a motor alimentary conditioned reflex to a four-minute interval of time. A connection has been established between the experimental characteristics of formation of a reflex to time and some parameters of the presumed dynamics of trace excitation. The analysis helped to establish the shortest and longest intervals to which a reflex to time can be elaborated by the mechanism of trace reflex, as well as the optimal interval to which it is elaborated more easily. The experimental results so obtained are a significant corroboration to the correctness of the Pavlov hypothesis.     

Correlations among cortical potentials in the dog during the elaboration of motor alimentary conditioned reflexes

Background electrocortical activity in a frequency band of 1-100 Hz of dogs with electrodes implanted in different neocortical areas was studied before and after elaboration of motor (lever pressing) alimentary conditioned responses. Conditioning led to a significant change of the distribution histograms of cross-correlation coefficients (CC) between the cortical potentials, i. e. the dispersion of CC values decreased and the level of correlation changed as well. In more tranquil animals (with lower CC values before conditioning) the level of correlation significantly increased, in excitable ones (with higher CC values before conditioning) it decreased. CC distributions after the conditioned response elaboration became similar in both cases apparently indicating the formation of a uniform state characteristic for the type of a conditioned response under study.