On the influence of an unconditioned reflex on a conditioned negative reflex

The formation of a temporary connection is based on one of the main conditions: the coincidence in time of the action of an indifferent agent with the action of an unconditioned stimulus. In this case, the coincidence should take place in such a way that the onset of the action of the indifferent agent, at least slightly, but precedes in time the action of the unconditioned stimulus. If the coincidence occurs from the precedence of the action of the unconditioned to the indifferent agent, it is not possible to develop a conditioned stimulus from the latter (Krestovnikov, Podkopaev). This fact must be understood in such a way that during the action of the unconditioned stimulus, the center of the unconditioned reflex, due to the mechanism of negative induction, causes inhibition that spreads to the cerebral hemispheres, and the indifferent stimulus falls on the cell in a state of inhibition.