Tonic background activity of 266 neurones in the hippocampus and different neocortical areas was studied in freely moving rabbits in the process of defensive and food instrumental conditioned performance and during switching-over of instrumental and classical food and defensive reflexes. Associations of CS and reinforcement evoke background activity changes in most of recorded cortical neurones preceding the development of other conditioned manifestations. Conditioned reflex was performed only after reaching the background firing rate of almost every examined neurone optimal for its realization. The performance of different conditioned reflexes was associated with different background activity levels of cortical neurones. The above mentioned data form the experimental basis for the identification of the tonic component in conditioned process which reflects tonic character of temporary connection formation and function.

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PubMedDate not supplied

[Dynamics of hippocampal neuronal activity during formation of conditioned avoidance reflexes].

Activity of 72 neurones of the dorsal hippocampus was studied in unrestrained rabbits during avoidance conditioning. In the process of conditioning, associative reorganization of neuronal activity were found, which were of a dynamic nature and depended on the stage of reflex stabilization. The initial stage of elaboration was characterized by a change in background activity between pairings in 87.5% of the hippocampal neurons, recorded in that period. Phasic associative reorganization recorded in 53.1% of neurons in response to a signal stimulus before the appearance of conditioned movements, reflected the orienting component of the conditioned reaction, reaction to time during the period of action of associated stimuli and a change in the level of neurons activity resulting from association of conditioned and unconditioned stimuli. The nature of response was changing in the most of the neurones at the appearance of the conditioned motor reaction. Stabilization of the level of background activity and of phasic responses of neurones to signal stimulus were observed at the stage of stable conditioned reflex. Phasic responses had several modifications which reflected a level of neuronal activity specific for the conditioned reflex, and they were also linked to signal involvement of the system providing for the movement. The data obtained show that participation of regulatory tonic mechanisms is an essential condition of the formation and manifestation of the temporary connection.

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PubMedDate not supplied

[The interaction of homogeneous motor conditioned reflexes during conditioned-reflex switchover: the transfer of learning and interference].

The dynamics of elaboration of the conditioned switchover (CSw) of homogeneous motor conditioned reflexes (CR) with different lateralization of the motor skill was studied in rabbits. Learning of CSw was shown to pass three basic stages characterized by different degree of consolidation of the CRs, by interaction between the two CRs, and by manifestation of CSw. Stages I and II reflected the process of afferent and efferent generalization of CRs and CSw, stage III was associated with specialization of CRs and CSw. Both positive and negative transfer of motor learning as well as interference between the two motor skills took place during CSw elaboration. The highest rate of CSw acquisition was observed in rabbits displaying positive motor transfer.

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PubMedDate not supplied

[The statistical evaluation of the reliability of learning curve differences].

A nonparametric method of statistical analysis of two related binary sequences of "1" and "0" is presented. This technique enables comparison between the dynamics of probability of appearance of 1" in the two sequences. This test can be applied to the problem of statistical comparison between the dynamics of learning of a "stimulus-reaction" type when the appearance of reaction to the stimulus is labeled as "1" and its absence as "0". The graphical interpretation is given and IBM-PC/AT program is characterized which realizes the advanced method.

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