Reversibility of reinforcement between eating and running by schedule changes: A comparison of hypotheses and models

Rats increased eating that produced access to a running-wheel or increased running that produced access to food, depending on which response was potentially deprived, relative to baseline, by the scheduled ratio of responding. Under both schedules, instrumental responding significantly exceeded appropriate baselines of the noncontingent effects of the schedule. The results contradicted the hypothesis that reinforcement is produced by an overall or momentary probability differential between two responses; instead, they supported the condition of response deprivation as a key determinant of reinforcement. Of several recent quantitative models that predict reversibility of reinforcement by schedule changes, only the predictions of the relative response-deprivation model did not differ significantly from the data of either schedule.