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A S Dmitriev

Publications and source records attributed to A S Dmitriev.

26 records · Page 2Linked to original sources
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[Comparative physiology of short-interval conditioned reflexes to time in different species of animals].

Conditioned reflexes (CR) to short time intervals (from 0.25 to 20 min) were studied in rabbits, white rats and pigeons by motor food-procuring method. Some significant distinctions between species were revealed. The mean duration of formation of CR to time in rabbits amounted to 74 pairings, in rats--to 121, in pigeons--to 217. The optimal time interval varied in rabbits from 2 to 10 min, in rats from 1 to 4 min and in pigeons in was from 1 to 1,5 min. The longest interval which allowed to form the trace CR to time was not in excess of 22 min in rabbits, 10 min in rats and 4-5 min in pigeons. The shortest interval was within 15-45 s. Unstable and incorrect CR to time was formed when the intervals were shorter or longer than the optimal one. The accuracy of CR to time was: in rabbits approximately equal to 0.93-0.95 in rats approximately equal to 0.85-0.94, in pigeons approximately equal to 0.78-0.85. The data obtained have satisfactory explanation in the light of I. P. Pavlov's hypothesis on physiological mechanism of CR to time.

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[Limits to formation of trace conditioned reflexes to time].

Conditioned reflexes to different time intervals (from 0.25 to 90 min) were elaborated in Wistar line rats by motor food-procuring method. A conditioned reflex to time is formed easier and attains highest precision to intervals from 1 to 4 min. With shorter (0.5 to 0.75 min) and longer (6 to 10 min) intervals, the reflex to time is unstable and not precise. To intervals beyond the 0.5 to 10 min range the conditioned reflex to time could not be formed by the above method. Experimental data are corroborated by theoretical estimations of the shortest and longest intervals to which it is possible to elaborate a conditioned reflex to time by trace reflex mechanism. The data obtained are considered as a confirmation of Pavlov's hypothesis on the physiological mechanisms of the process of formation of a short-interval conditioned reflex to time.

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[Conditioned reflexes to the ratio of time intervals].

Conditioned reflexes to relation of temporal intervals, as a specific variety of reflexes to stimuli ratios, were studied in rats during alternation of two homogeneous trace stimuli with their separate reinforcement; the stimuli were addressed to one analyser, but were of different duration. Formation of conditioned reflexes to the ratio of temporal intervals began in rats after eleven sessions (106 pairings) on the average. The total duration of the whole process of formation up to stabilization of the reflex varied from 20 to 40 sessions (31 on the average), or from 200 to 394 pairings (308 on the average). The process of formation was the longer the less the ratio between the compared intervals (of a longer to a shorter one). The precision of the formed conditioned reflex to the ratio of temporal intervals (as expressed in the probability of correct reactions) amounted to 0.71% on the average. The experimental data may be satisfactorily explained in the light of concepts of Pavlovian school on the physiological mechanism of conditioned reflexes to stimuli ratios.

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