Date of Award


Degree Name

Master of Arts



First Advisor

Dr. Alan D. Poling

Second Advisor

Jack Michael

Third Advisor

Lisa Baker

Access Setting

Masters Thesis-Campus Only


Groups of eight experimentally-naive rats were exposed during 8-hr sessions to resetting delay procedures where responses on one (the reinforcement) lever produced water after a delay of 8, 16, 32, or 64 s. For rats in one condition, responses on a second (no consequences) lever had no programmed consequences. For rats in another condition, responses on a second (cancellation) lever during a delay initiated by a response on the reinforcement lever prevented delivery of the scheduled reinforcer; responses on the cancellation lever at other times had no programmed consequences. Under both conditions and at all delays, most subjects emitted more responses on the reinforcement lever than control rats that never received water emitted on either lever. At 8-s delays, both conditions engendered substantially more responding on the reinforcement lever than on the other lever, and performance closely resembled that of immediate-reinforcement controls. At delays of 16 and 32 s, however, there was clear differential responding on the two levers under the cancellation condition, but not under the other condition. When the delay was 64 s, differential responding on the two levers did not occur consistently under either condition.

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