For the formation of conditioned reflexes, as is known, the coincidence of the conditioned stimulus in time with the unconditioned one, for example, with food, is required. If reflexes have already been formed, that is, the food reaction in children opening the mouth and the separation of saliva appears after the onset of the action of the conditioned stimulus, then in order for them not to fade away, the action of the conditioned stimulus must be reinforced by giving some food substance, which causes child a series of chewing movements and increased salivation, unconditioned secretion of saliva. Thus, in our experiments, we have the opportunity to take into account the values of both conditioned and unconditioned salivation and their relationship to each other. As is known, a conditioned secretory reaction is composed of several moments: the energy from a conditioned external stimulus is transformed into a nervous process of irritation, which captures a certain group of cells of a particular analyzer in the cerebral cortex. Then this irritation is carried out, apparently, to the food center and further to the centers of salivation, which cause the salivary glands to function. The intensity of conditioned salivation depends, therefore, on the excitability of the cells of the cerebral hemispheres and further on the food center. If the conditioned stimulus evokes a weak stimulus process in the corresponding part of the cortex, then it is clear that the conditioned secretion of saliva is also low. A decrease in the excitability of the food center also leads to a significant weakening of conditioned reflex activity.
On the ratio of conditioned and unconditioned saliva secretion on well-formed conditioned reflexes