What is the term for when a previously extinguished response suddenly reappears after a period of time?

The term that describes the phenomenon where a previously extinguished response suddenly reappears after a period of time is spontaneous recovery. This concept is an essential aspect of classical conditioning, first studied by Ivan Pavlov.

When a conditioned response has been extinguished—meaning that the conditioned stimulus no longer elicits the conditioned response after being presented without the unconditioned stimulus for some time—spontaneous recovery can occur if the conditioned stimulus is presented again after a rest period. This indicates that the learning has not been completely erased but is instead inhibited, revealing the underlying memory of the association that remains retrievable under certain conditions.

This recovery of the response can be surprising, as it occurs without any additional training, highlighting the complexity of how learned behaviors can be retained even after they seem to vanish. Understanding this concept helps in grasping how associative learning works over time and contributes to broader discussions on memory and behavior.