Figure 1.

Relapse of fear after extinction. After the extinction of a conditioned fear response, extinction, the expression of conditioned fear is reduced. However, a number of phenomena are associated with the return or relapse of fear responses after extinction. These include (a) spontaneous recovery with the passage of time, (b) external disinhibition after presentation of a novel stimulus, (c) reinstatement after experiencing a noxious event, including the unconditioned stimulus, and (d) renewal after experiencing the conditioned stimulus outside the extinction context.