Running and drinking by rats outside the schedule session

Two experiments measured the effects of a contingency schedule relating running and eating on the behavior of rats during an "experimental hour" and during two hours before and afterwards. The behaviors recorded during the surrounding hours were drinking and perching (Experiment 1) and running, drinking and perching (Experiment 2). The temporal pattern of drinking in both experiments was unaffected by changes in conditions during the experimental hour. However, drinking prior to the experimental hour in Experiment 2 was less than in Experiment 1 probably due to competition from wheel running. Rats showed unreliable patterns of perching in both experiments. Finally, running increased both within and outside the experimental hour during the schedule conditions. The increase in wheel running surrounding the schedule hour may represent a combination of species-typical foraging responses and the failure of stimulus control of instrumental behavior. These data suggest that behavior regulation and optimality theories may need to consider the species-typical mechanisms and stimulus control necessary for animals to integrate behavior over time.