An analysis of renewal following fading of reinforcer type.

Abstract

Renewal is defined as relapse of a previously extinguished target behavior following a change in context. This form of relapse has been shown to occur when an alternative source of reinforcement that was made available during extinction of the target response is abruptly switched to a different type of reinforcement. The current experiment examined a method for mitigating renewal produced by switching reinforcement by fading reinforcer type during extinction. In Phase 1, rats' target-lever pressing was reinforced with one type of reinforcement (O1). In Phase 2, lever pressing was extinguished and noncontingent reinforcers were delivered. The forward fading group initially experienced all alternative (O2) reinforcement, and the percentage of O1 reinforcement was increased across sessions. The reverse fading group initially experienced 90% O1 and 10% O2 reinforcement, and the percentage of O2 reinforcement was increased across sessions. A third group received delivery of O2 only, serving as a control. In Phase 3, all groups received noncontingent delivery of O1 reinforcement only. Robust renewal was seen in the control group relative to both fading groups. Furthermore, levels of renewal were lower and did not differ significantly between the forward fading and reverse fading group. These findings provide further insight into the role of context in relapse and may provide suggestions for future clinical applications.