Effects of stimulant drugs on self-control choices in pigeons : determining behavioral mechanisms of drug action

UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
Stacy M. Febbo (Creator)
Institution
The University of North Carolina Wilmington (UNCW )
Web Site: http://library.uncw.edu/

Abstract: The present study attempted to identify behavioral mechanisms of stimulant effects on “self-control” choices in pigeons. The experimental procedure required pigeons to respond on a single random interval (RI) 1 min schedule in order to choose between a smaller, more immediate reinforcer (1 s food after 2 s delay) and a larger, more delayed reinforcer (4 s food after 2 to 40 s delay). While the signaled delay to the smaller option remained 2 s throughout the session, the signaled delay associated with the larger option increased across five, 10 min blocks from 2 s to 40 s. In this way delay-discount functions were obtained within each experimental session. Once stable delay-discount functions were obtained, methylphenidate (MPD) (0.0 – 17.0 mg/kg) and methamphetamine (METH) (0.0 – 3.0 mg/kg) were administered via i.m. injections. Using a logarithmic variation of Herrnstein’s matching law, an attempt was made to separate changes in the sensitivity to delay (SD) from changes in the sensitivity to amount (SA). Overall, MPD and METH increased choices of the larger, more delayed reinforcer. Moreover, MPD’s and METH’s primary effects were a decrease in SD, although concomitant decreases in SA occasionally occurred. It is concluded that quantitative methods such as those used here may prove useful in elucidating behavioral mechanisms of drug action.

Additional Information

Publication
Thesis
A Thesis Submitted to the University of North Carolina at Wilmington in Partial Fulfillment Of the Requirements for the Degree of Master of Arts
Language: English
Date: 2009
Keywords
Choice (Psychology), Pigeons--Behavior, Reinforcement (Psychology)
Subjects
Pigeons -- Behavior
Reinforcement (Psychology)
Choice (Psychology)