Сonditioned Reflex Chamber
In the process of studying conditioned reflexes in dogs, Pavlov came to the need to isolate the dog as much as possible from external stimuli during the experiment.

For this purpose, Pavlov’s closest associates, N.A. Podkopaev and E.A. Ganike chamber had a double door that was tightly closed during the experiment.

Conditioned stimuli were fed by pressing the keys of a special panel. Reinforcement was supplied by pressing on the balloon connected by a rubber tube with a mechanism that rotates the cups in the meat-rusk powder feeder. We observed the behavior of the dog through a periscope.

Thus, conducting experiments on the development of conditioned reflexes in such a chamber ensured complete isolation of the experimental animal from any extraneous influences during the experiment.

The equipment of such a chamber included instruments and devices for the implementation of various influences on the experimental animal and the registration of its responses in the process of conditioned reflex activity. The impact on the animal was limited to sound, light, mechanical, chemical or electrical irritants. At first, only the secretion of saliva was recorded, and later — the heart rate and other indicators.

Research carried out in the laboratory of I.P. Pavlov showed that the stimulus is not only the presence of a stimulus but also its absence. To study the effect of a sharp limitation of influencing stimuli, called sensory isolation, various variants of chambers have been proposed which can provide various forms of isolation of the experimental object from the environment.