Response-Outcome versus Outcome-Response Associations in Pavlovian-to-Instrumental Transfer: Effects of Instrumental Training Context

Abstract

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.

Figure 1

Mean elevation scores during the choice tests conducted in the Pavlovian training context for responses to the same and different (Diff) lever by animals in Group Differential (GP D) and Group Non-Differential (Gp NonD). Error bars show +/− 1 SEM.

Figure 2

Mean elevation scores during choice tests conducted in the instrumental training contexts. Data are shown separately when “same” responses were tested in their retrieved and non-retrieved contexts for animals in Group Differential, and in both contexts combined for Group Non-Differential. Error bars show +/− 1 SEM.