Factors that encourage generalization from extinction to test reduce resurgence of an extinguished operant response

Two experiments investigated methods that reduce the resurgence of an extinguished behavior (R1) that occurs when reinforcement for an alternative behavior (R2) is discontinued. In Experiment 1, R1 was first trained and then extinguished while R2 was reinforced during a 5- or 25-session treatment phase. For half the rats, sessions in which R2 was reinforced alternated with sessions in which R2 was extinguished. Controls received the same number of treatment sessions, but R2 was never extinguished. When reinforcement for R2 was discontinued, R1 resurged in the controls. However, the alternating groups showed reduced resurgence, and the magnitude of the resurgences observed during their R2 extinction sessions decreased systematically over Phase 2. In Experiment 2, R1 was first reinforced with one outcome (O1). The rats then had two types of double-alternating treatment sessions. In one type, R1 was extinguished and R2 produced O2. In the other, R1 was unavailable and R2 produced O3. R1 resurgence was weakened when O2, but not O3, was delivered freely during testing. Together, the results suggest that methods that encourage generalization between R1 extinction and resurgence testing weaken the resurgence effect. They are not consistent with an account of resurgence proposed by Shahan and Craig (2017).