Psychological distance to reward: Effects of S+ duration and the delay reduction it signals

A concurrent-chains procedure was used to examine choice between segmented (two-component chained schedules) and unsegmented schedules (simple schedules) in terminal links with equal inter-reinforcement intervals. Previous studies using this kind of experimental procedure showed preference for unsegmented schedules for both pigeons and humans. In this study, two changes in the experimental procedure were made relative to the usual experimental procedure reported in the literature. The first was that in the segmented schedule the second terminal-link stimulus appeared close to reinforcement presentation and the second was that the change in stimulus was brief, allowing the first stimulus to reappear and to be contiguous with reinforcement. With these changes, preference occurred for the segmented schedule. This result is consistent with principles of conditioned reinforcement, including delay-reduction theory.