Table 2.

Recovery or “relapse” effects that occur after extinction (or other forms of retroactive interference) in Pavlovian and instrumental learning

Phenomenon	Description
Renewal	Recovery of extinguished behavior that occurs when the context is changed after extinction. Most often studied when the subject is returned to the original context of conditioning after extinction in a second context (ABA renewal), but it can also occur when the animal is removed from the extinction context and tested in another “neutral” context (ABC renewal; AAB renewal).
Spontaneous recovery	Recovery of extinguished behavior that occurs when the conditioned stimulus (CS) or instrumental response is tested after time has passed following the conclusion of extinction.
Reinstatement	Recovery of extinguished behavior that occurs when the subject is exposed to the US or reinforcer after extinction. Can be controlled by contextual conditioning produced when the Outcome is presented, hence the phenomenon is often strongest in the context in which the Outcome has occurred. Can also occur if the US or reinforcer is itself part of the “context” of acquisition.
Reacquisition	Recovery of responding that occurs when the CS is paired with the US again (Pavlovian), or the response is paired with the reinforcer again (instrumental), after extinction. Often rapid, especially when cues in the background renew conditioned performance (as above). Can be slow when the background cues continue to retrieve extinction.
Resurgence	Recovery of an extinguished instrumental behavior that occurs when extinction is introduced for a second instrumental behavior that has been reinforced to replace it. Almost exclusively studied in instrumental/operant learning.