International Journal of Comparative Psychology

One experiment with rats used Pavlovian-to-instrumental transfer (PIT) tests to explore potential competitive interactions between Pavlovian and instrumental processes during instrumental learning. Two instrumental response-outcome relations (e.g., left lever – grain pellets, right lever – sucrose pellets) were first trained in distinct contexts for one group of rats (Group Differential) or in each of two contexts for a second group (Group Non-Differential).  Both of these groups then received training with two Pavlovian stimulus-outcome relations in a third experimental context.  Selective PIT tests conducted in both the Pavlovian and instrumental contexts revealed greater selective PIT in Group Non-Differential than in Group Differential subjects.  This result is discussed in terms of the roles played by context-outcome, response-outcome, and outcome-response associations during instrumental learning. The results further help us understand the nature of Pavlovian-instrumental interactions in specific PIT tasks.