Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Date of Award

Summer 2010

Document Type

Thesis

Degree Name

Master of Arts (MA)

Department

Department of Graduate Psychology

Abstract

Some researchers have suggested that the discrepancy in findings between studies of resistance-to-extinction that use single-schedules and those that use multiple-schedules is the result of increased discriminability between training and extinction conditions in the single-schedule preparation, masking the true relation between reinforcer density and resistance to extinction. Because d-amphetamine has been shown to interfere with stimulus control in a number of preparations, the current study examined the effects of d-amphetamine on rats’ lever-pressing in the context of a single-schedule resistance-to-extinction preparation. During training, doses of d-amphetamine or vehicle were administered 15 min prior to sessions in which the delivery of reinforcers occurred according to variable-interval 10-s, 90-s, or 240-s schedules. A 2-hr extinction session followed the 50-min training sessions, which occurred 5-7 days per week for each rat for at least 15 sessions. Pre-session injections of d-amphetamine resulted in higher resistance to extinction across all training schedules than pre-session injections of vehicle did, but d-amphetamine did not change the direction of the relation between reinforcer density and resistance to extinction. I discuss the results in a context that emphasizes the commonalities between resistance to extinction procedures completed in discrete trials and free-operant contexts with the hope of bridging the gap between these two bodies of literature.

Included in

Psychology Commons

Share

COinS