Combined effects of reinstatement and spontaneous recovery.

Prior research has examined combined forms of behavioral recurrence, showing that relapse is greater when these forms occur together than when each is studied in isolation. However, this enhancement effect has not yet been explored in the joint expression of two phenomena: reinstatement, defined as the reappearance of extinguished behavior following response-independent or response-dependent exposure to consequences (or consequence-associated cues), and spontaneous recovery, defined as the recurrence of a response after an interval following extinction. The present study evaluated whether delaying the test phase enhances response-independent reinstatement in rats. After reinforcement and extinction of a response, subjects were assigned to one of two groups: Control Group, which was exposed to an immediate test with delivery of non-contingent reinforcement, or Delay Group, which was exposed to the same test after a seven-day delay. Results showed that reinstatement was higher in the Delay Group compared to the Control Group. These findings offer new support for enhanced recurrence paradigms, showing that reinstatement and spontaneous recovery jointly produce greater relapse.