Figure 6.

This figure shows activity scores (mean ± SEM) for rats tested at different retention intervals on the three tests of conditioning in Experiment 2. Figure 5a depicts the shortest retention interval in which drug-free and drug-challenge tests occurred 24 and 48 hrs, respectively, after the novelty-conditioning phase. Figure 5b shows activity scores for the longer retention intervals. Specifically, drug-free testing occurred 14 and 28 days after conditioning and drug-challenge testing occurred 15 and 29 days after conditioning. PC= place conditioning, DF= drug-free test, DC= drug challenge test.

* Indicates significant difference on the drug challenge test in comparison to the drug-free test for both groups.