Conditioned Inhibition

(also internal inhibition), in physiology, the process whereby the conditioned reflex is inhibited through lack of repeated reinforcement by the unconditioned stimulus. The concept of conditioned inhibition was introduced by I. P. Pavlov, who made the distinction between conditioned and unconditioned, or external, inhibition.

Four types of conditioned inhibition may be distinguished, depending on the method used in the process: (1) extinction, which results when a positive signal is not reinforced by the unconditioned stimulus; (2) differential inhibition, which takes place in the absence of reinforcement of the response reaction to one of two related conditioned signals; (3) disinhibition, which is a variant of a complex type of differentiation and occurs when the conditioned positive signal is applied without reinforcement together with some other external agent; and (4) delayed inhibition, which occurs when the conditioned stimulus is not reinforced by the unconditioned stimulus within the first few minutes—with the result that the stimulus during this interval becomes inhibitory; as the conditioned reflex is inhibited, its delayed action is brought closer in time to the moment of effective action by the unconditioned stimulus.

Conditioned inhibition is the result of the conflict of two systems of excitation.