Evidence that extinction results in context-mediated learning comes from situations in which, following extinction, reestablishing the original conditioning context restores responding (see Bouton, 2004, for a review). For instance, first training a CS-US association in one context (Context A), followed by extinguishing the CS in a different context (Context B), and finally reintroducing the original Context A produces a marked increase in responding to the CS, even in the absence of the US (Bouton and King, 1983 and Bouton and Peck, 1989). These findings suggest that learning about the CS-US relation is preserved throughout extinction despite elimination of conditioned performance; re-exposure to the original conditioning context reveals this preserved learning. Related phenomena in which responding readily recovers following extinction, such as spontaneous recovery and rapid reacquisition, are attributed to a failure to retrieve the extinction memory when testing occurs outside of the temporal or stimulus context mediating extinction.