What is spontaneous recovery in classical conditioning?

Spontaneous recovery refers to the phenomenon where a conditioned response, previously extinguished, reappears after a rest period or a pause in the conditioning context. After extinction occurs—when the conditioned stimulus is presented without the unconditioned stimulus, leading to a decrease in the conditioned response—there may come a time when the conditioned stimulus is presented again, and the conditioned response reemerges, even though it had been thought to be entirely eliminated.

This reappearance suggests that the learned response is not completely forgotten but rather is temporarily suppressed. The key aspect is that this recovery occurs spontaneously after a period during which the conditioned stimulus has not been paired with the unconditioned stimulus again. Understanding spontaneous recovery is important because it highlights the complexities of learning and memory processes in humans and animals, and it illustrates that extinction does not erase learning but instead leads to a different behavioral state.