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Results for “REFLEX, CONDITIONED”

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At least 19 recordsLinked to original sources
PubMedDate not supplied

[Dynamics of elaboration of conditioned reflex switching over of dissimilar instrumental conditioned reflexes].

Conditioned switching over of heterogeneous instrumental reactions was elaborated in four dogs. The action of a fan served as a switch from alimentary to a defensive situation. In the alimentary situation, the animal, in response to a conditioned stimulus, pressed the pedal with its right foreleg and, in a defensive situation, in response to the same signal, lifted the left paw attached to the lever. In some dogs the switching over was elaborated quite rapidly and easily, while in others it was achieved only on some days of the experiment. In the course of elaboration of the switching over, the animals responded to the trigger signal with bieffector reactions. The basic features of the dynamics of switching over elaboration revealed for classic conditioned reflexes also proved valid for instrumental conditioned reflexes.

Animals↗
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.

Animals↗
PubMed1991

[Inhibiting effect of the presentation of additional stimuli on neuronal responses in the cat sensorimotor cortex during a conditioned reflex].

Conditional responses of the sensomotor cortex neurons were registered in awake cats which were trained to respond to presentation of conditional stimuli (a single sound click) by instrumental conditional movement. Those neuronal responses were registered 50-150 ms before realization of reflex movements. During external stimulation after the reflex beginning, conditional neuronal reactions appeared 50-250 ms later, but the latencies of conditional movements did not change. It is supposed that the studied phenomenon is a result of the growing exteroceptive attention of cats to external stimulation.

Acoustic Stimulation↗
PubMedDate not supplied

[Effect of unilateral extirpation of the superior cervical sympathetic ganglion and electric stimulation of the posterior hypothalamus on the rate of reflex conditioning in the dog].

The influence of the sympathetic nervous system and the posterior hypothalamus on the rate of conditioning and the magnitude of conditioned reflexes was studied on dogs by motor defensive method. Extirpation of the superior cervical sympathetic ganglion reduced the conditioned reflex magnitude, delayed the elaboration of positive reflexes facilitating the formation of the inhibitory process. Stimulation of the posterior hypothalamus with electrical current of medium strength (50 mcA) promoted the enhancement of positive conditioned reflexes, and while not substantially affecting the rate of their formation, facilitated elaboration of internal inhibition.

Animals↗
PubMed1976

[Formation and development of motor-defense conditioned reflexes in rats of different ages].

The analysis of the reflex conditioned activity of rats at various age groups showed that there were differences in it. There was a considerable strength of the excitatory process in young rats, aged one and a half months. The positive reflexes to sound and light stimuli were formed compatively quickly (on the average after 8,6 and 4,8 combinations of the conditioned stimulus with the unconditioned stimulus) in comparison with the animals of mature age (respectively 16,5 and 8 combinations). In the old rats the author observed a lowering of the strength of the excitatory process and slower formation and stabilization of the positive conditioned reflexes. A gradual formation of the inhibitory function occurs during the process of ontogenetic development and this finds an expression in the unpossibility for the fromation of differentiation in young animals and the presence of such in 10-month old rats. The level of the differentiations in these animals reached 60,1% and 76,9%. The latent period changed with the advancement of age. In adult animals there was some shortenint ofthelatent period in comparison with the young animals although the difference was statistically insignificant. There was an increase of the absolute values of the latent period again after the occurrence of the old age (5,2'' and 4,52''). The indicated peculiarities in the formation and course of the conditioned reflexes probably were connected with various degree in the fluctuations of the strength of the exitiatory and inhibitory processes in the central nervous system during ontogenesis.

Age Factors↗
PubMedDate not supplied

[Inhibiting and facilitating influences from the caudate nucleus on alimentary conditioned reflexes].

Alimentary conditioned reflexes were studied in dogs during electrical stimulation of different zones of the caudate nucleus head with a 80 to 100 microampere current, of 5 c/s frequency and 0.5 msec pulse duration. The inhibitory influences came from the ventrolateral, and the activating ones, from the dorsal and central zones of the caudate nucleus head. Changes of conditioned reflexes resulting from its stimulation depended on the strength of the conditioned signals: the conditioned reflex to a weak stimulus (light) was more readily subject to changes as compared with the one to a strong signal (a metronome). The magnitude of unconditioned reflexes did not change in these experiments.

Animals↗