Spontaneous recovery

In classical conditioning, spontaneous recovery or resurgence in operant conditioning, is the reemergence of a conditioned response which has been previously extinguished. Spontaneous recoveries tend to yield somewhat muted responses in which extinction occurs more readily.

For example, a dog's conditioned response of salivating to a bell will often, after it has been extinguished, reappear when the dog later hears the sound of a bell. This phenomenon is known as "spontaneous recovery." To Pavlov (1972), the phenomenon of spontaneous recovery indicated that extinction is not simply a process of unlearning the conditioning that has taken place. Rather, extinction involves learning something new, namely, to inhibit the occurrence of the conditioned response in the presence of the conditioned stimulus. For example, rather than unlearning the the response of salivation to the metronome during extinction, the dog learns to inhibit the response of salivation to the metronome, with the connection between metronome and salivation remaining intact on some underlying level. Spontaneous recovery may therefore represent the partial dissipation of this inhibition during the rest period between extinction sessions.

Spontaneous recovery helps explain why it is so hard to overcome drug addictions. For example, cocaine addicts who are thought to be "cured" can experience an irresistible impulse to use the drug again if they are subsequently confronted by a stimulus with strong connections to the drug, such as a white powder (O'Brien et al., 1992; Drummond et al., 1995; DiCano & Everitt, 2002).