Abstract
We have found that pigs learn to press a lever several times consecutively before consuming their reward under a continuous reinforcement (CRF) schedule of operant conditioning. The present study examined determinants of the magnitude of consecutive responses. In Experiment 1, the magnitude of consecutive responses was greater when the lever-feeder distance was far (385 cm) than when it was near (19 cm). This result supports the hypothesis that consecutive responding is a foraging strategy to reduce the traveling cost required for shuttling behavior between the lever and the food cup. In Experiment 2, the number of consecutive responses was gradually decreased and approached the target magnitude by selectively reinforcing a smaller number of consecutive responses. These findings suggest that pigs are sensitive to the relation between response cost and reward gain to some extent, and can adjust their behavior to a fine degree with salient feedback.
