State-dependent or "dissociated" Learning Produced with Pentobarbital.

Rats were trained to escape from shook in a T maze. A response learned by S while it was drugged with 25 mg/kg sodium pentobarbital failed to appear if S was subsequently tested while not drugged. Conversely, a response learned by S while undrugged did not occur if S was tested while drugged. In both cases performance of the response was dependent upon reinstatement of the drug condition present during training. The amount of transfer of training between nondrug and drug states was shown to be inversely proportional to the size of the drug dose used to establish the drug state. The role of external and internal stimuli, as agents producing state-dependent performance, was experimentally evaluated.