International Journal of Comparative Psychology

Two experiments with rats studied the relationship between reinforcer magnitude and frequency, and extinction rate in a consummatory situation with rats. In Experiment 1, groups received access to either a 2% or a 32% sucrose solution during twenty 5-min sessions and were subsequently shifted to extinction (access to an empty sipper tube). Goal tracking time (time spent near the sipper tube) was the dependent measure. Extinction was faster after training with 2% solution than with 32% solution. In Experiment 2, extinction was faster after training with 50% partial reinforcement than with continuous reinforcement. In both experiments, extinction was gradual and rats exhibited spontaneous recovery of goal-tracking behavior. Results are discussed in the context of evidence pointing to a dissociation of consummatory and instrumental behavior.