Transfer between Pavlovian facilitators and instrumental discriminative stimuli

Abstract

Two experiments assessed the degree to which Pavlovian facilitators were interchangeable with instrumental discriminative stimuli (S ds). In Experiment 1, rats were trained in a Pavlovian paradigm in which one stimulus (i.e., a facilitator) signaled the reinforcement of another stimulus (i.e., a target). Next, the rats were given instrumental discrimination training in which an S d signaled the reinforcement of barpressing. A transfer test then assessed the capacity of the Pavlovian facilitator to promote barpressing. The results showed that the facilitator promoted significant barpressing, both when it was presented alone and when it was presented in compound with the S d. Reliable transfer was not obtained with a "pseudofacilitator" control stimulus that, during training, was uninformative about the reinforcement of its target. Experiment 2 showed that a stimulus trained as an instrumental S d reliably augmented responding to a stimulus previously trained as a target in a Pavlovian facilitation paradigm. A "pseudo-S d" that, during training, was uninformative about the reinforcement of barpressing failed to promote such transfer. These results show that Pavlovian facilitators and instrumental S ds are interchangeable to a significant degree, and suggest that facilitators and S ds may act via similar mechanisms. © 1988 Psychonomic Society, Inc.