(A) Effect of OFC lesions on reversal learning. Sham and OFC-lesioned rats were tested on serial reversals of a post-operatively acquired 2-odor go, no-go discrimination. One odor predicted sucrose availability, while a second odor predicted quinine. Rats had to learn to respond for sucrose but withhold responding for quinine; criterion was 90% correct responding in a block of 20 trials. OFC lesions had no effect on retention but impaired reversal learning. (B) Effect of repeated non-contingent cocaine exposure (30 mg/kg/day X 14 days) on reversal learning. Rats were injected with cocaine or saline and were then tested on the same odor discrimination reversal task used in (A) after approximately 1 month of withdrawal from the drug. Cocaine exposure had no effect on retention but impaired reversal learning. (C) Effect of contingent cocaine self-administration (0.75 mg/kg/infusion, 4 h/day X 14 days) on reversal learning. Rats were trained to self-administer cocaine and then tested on the same odor discrimination reversal task used in (A) after approximately 3 months of withdrawal from the drug. Cocaine self-administration had no effect on retention but impaired reversal learning. * Different from the respective controls, p < 0.05. Data in (A), (B), and (C) were adapted from references 49, 64 and 80, respectively.