As with bilateral Pf lesions, no effect was observed on initial acquisition of instrumental performance (Figure 4B; there was an effect of linear acquisition, F (1, 21) = 125.32, p = 0.001, but not of group, F (1, 21) = 3.79, p = 0.065, and no interaction, F (1, 21) = 2.32, p = 0.143). Further, each group was similarly sensitive to outcome devaluation after initial training and adjusted their choice performance in the extinction test toward the nondevalued action (Figure 4C). Statistical analysis

found an effect IWR-1 of devaluation, F (1, 21) = 54.82, p = 0.001, but no effect of group, F (1, 21) = 0.05, p = 0.82, and no interaction between these factors, F (1, 21) = 0.84, p = 0.36. Rats were then retrained and assessed for

their sensitivity to contingency degradation. As is clear from Figures 4D and 4E, although the sham and ipsilateral control groups were both sensitive to degradation, rats given the disconnection, i.e., Group Contra, were not. Specifically, Groups Sham and Ipsi selectively reduced responding on the degraded lever during both training (Figure 4D) and test (Figure 4E), whereas Group Contra responded similarly on both levers, clearly maintaining, or even mildly continuing to increase, performance on both actions across the sessions of degradation. In the analysis of degradation training data (Figure 4D), we found a main effect of group, F (1, 21) = 13.73, p = 0.004, and of degradation, F (1, 21) = 18.27, p = 0.001, and, importantly, a significant group × degradation interaction, F (1, 21) = 7.86, p = 0.011.

Luminespib Simple effects analyses reveal that this interaction consisted of a degradation effect (i.e., nondegraded > degraded) in both the Sham, F (1, 21) = 6.92, p = 0.016, and Ipsi, F (1, 21) = 21.1, p = 0.001, groups but no degradation effect (i.e., nondegraded = degraded) in Group Contra, F (1, 21) = 0.03, p = 0.86. Similar analysis of the test data (Figure 4E) again found no main effect of group, F (1, 21) = 0.01, p = 0.934, a main effect of degradation, F (1, 21) = 16.43, p = 0.001, and a group × degradation interaction, F (1, 21) = 5.60, p = 0.028, with simple effects showing a significant effect of degradation in the Sham, F (1, 21) = 4.41, p = 0.048, and Ipsi, F (1 21) = 20.37, p = 0.001, groups but not in the Contra group, F (1, 21) = 0.17, p = 0.684. Group Contra was similarly impaired after about reversal of the instrumental contingencies. Again, the lesions did not significantly affect performance on the levers during retraining on the reversed contingencies (Figure 4F); there was a main effect of linear acquisition, F (1, 21) = 22.71, p = 0.001, but no effect of group, F (1, 21) = 1.43, p = 0.245, and no group × acquisition interaction (F < 1). Nevertheless, the ability of the rats in Group Contra to retrieve the new contingencies on test was significantly impaired: Group Sham and Group Ipsi both showed a significant outcome devaluation effect (i.e.