[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.