Spontaneous recovery can be prevented in appetitive conditioning with rats

Abstract

Two Pavlovian appetitive conditioning experiments with rats demonstrated that spontaneous recovery can be strongly reduced (prevented). The experiments also investigated potential common factors associated with that prevention of spontaneous recovery after extinction. After pairings of a conditioned stimulus (CS) with a food unconditioned stimulus (US), an extinction cue (EC) was presented during extinction and spontaneous recovery testing with the CS. Replicating Brooks and Bowker (2001), EC–US pairings in the CS extinction–test interval subsequently resulted in the EC strongly reducing (preventing) spontaneous recovery to the CS (Experiment 1). Experiment 1 also assessed an “erasure” hypothesis of how the EC may reduce spontaneous recovery. Experiment 2 assessed EC– or US–alone presentations, or unpairings of EC and US, in the CS extinction–test interval. Spontaneous recovery was also prevented when the EC was presented alone or unpaired with the US, but USs alone interfered with the EC’s spontaneous recovery–preventing effect. No evidence was found for the EC operating by erasure, conditioned inhibition, generalized extinction, or generalized extinction. Together the results suggest that after CS extinction additional EC presentations are sufficient to prevent spontaneous recovery.