Control of instrumental performance by Pavlovian and instrumental stimuli.

Two experiments used rats to examine the transfer of control of a stimulus to a new instrumental response. That transfer was successful to the degree that the stimulus and the response shared a common outcome. The transfer was more substantial, however, when the stimulus signaled the availability of that outcome for another instrumental response compared with signaling its occurrence in a Pavlovian manner. That result suggests that the stimulus-outcome associations formed during instrumental training are not reducible to a Pavlovian association.