INHIBITORY STIMULUS CONTROL AND THE MAGNITUDE OF DELAYED REINFORCEMENT

• Published in: Journal of the experimental analysis of behavior 1974-05, Vol.21 (3), p.501-509
• Main Author: Richards, Ralph W.
• Format: Article
• Language: English
• ISSN: 0022-5002; 1938-3711
• DOI: 10.1901/jeab.1974.21-501

The key pecking of pigeons was reinforced according to a variable-interval 1-min schedule during each of two successively presented stimuli. When the key was illuminated by a black line on a white background, reinforcement was delayed for 10 sec. When the key was illuminated by a plain white light, reinforcement was not delayed. For half of the subjects, the delayed reinforcer was 4.0-sec access to mixed grain, and for the remaining subjects it was 1.5-sec access. The immediate reinforcer was 1.5-sec access for all subjects. All subjects responded at a lower rate during the presentation of the black line; no between-group difference in terms of terminal response rate during the presentation of the line was found. However, subjects that received 4.0 sec of delayed reinforcement responded at a lower terminal rate during presentation of the plain white light than subjects that received 1.5 sec of delayed reinforcement. A subsequent generalization test along the line-orientation dimension produced flatter U-shaped gradients for subjects that received 4.0-sec of delayed reinforcement.