A comparison of explicitly unpaired treatment and extinction: Recovery of sign-tracking within a context renewal design

The present experiment compared the effectiveness of explicitly unpaired treatment and extinction in preventing the recovery of sign-tracking within a context renewal design. Three groups of rats were first trained on a sign-tracking procedure in Context A where insertions of a retractable lever were paired with food. In a second phase, the sign-tracking response was eliminated. One group received standard extinction of the CS in Context B, while another group received explicitly unpaired treatment in Context B where food was presented only during inter-trial intervals (and not paired with the lever). A third group received this explicitly unpaired treatment in Context A. After the sign-tracking response was eliminated, all groups received a test session in Context A where the lever was presented alone and no food was delivered at any time. Significantly more responding occurred in the group that received explicitly unpaired treatment in Context B than in either of the other groups. This demonstrates that there are situations where explicitly unpaired treatment is less effective than extinction in preventing the reappearance of previously eliminated responding.

Research highlights▶ Explicitly unpaired training (as compared to extinction) in Context B led to more recovery of sign-tracking in a context renewal design. ▶ A context change during the response-elimination phase enhanced the recovery of responding in a Pavlovian resurgence design. ▶ Results suggest that explicitly unpaired treatment is not always better than extinction in preventing the reappearance of previously eliminated responding.