Date of Award:

5-2016

Document Type:

Dissertation

Degree Name:

Doctor of Philosophy (PhD)

Department:

Psychology

Committee Chair(s)

Gregory J. Madden

Committee

Gregory J. Madden

Committee

Amy L. Odum

Committee

Caitlin V. Buhusi

Committee

Timothy A. Shahan

Committee

Timothy A. Gilbertson

Abstract

Prior research indicates that drug dependence is associated with a tendency to discount the future. For instance, compared to control participants, drug-dependent participants more strongly prefer small, immediate rewards (e.g., $10 now) over larger, delayed rewards (e.g., $100 in 6 months). Similarly, in animal models of addiction, impulsive preference for small, immediate over larger, delayed food rewards in rats is associated with greater consumption of a number of drugs of abuse, including alcohol, cocaine, and nicotine. These and other findings suggest that this form of impulsive choice plays a causal role in addiction; however, this account has not been tested rigorously in an experimental context. Additional human and nonhuman research is needed to examine whether impulsive choice directly influences drug use. Findings from this research will improve basic understanding and perhaps aid in development of clinical treatments for addiction.

The research reported in this document developed and refined an experimental method (prolonged pre-exposure to delayed rewards) that produces long-lasting reductions in impulsive choice in rats and determined the effects of this method on subsequent alcohol consumption. If impulsive choice plays a direct, causal role in rodent alcohol consumption, then reductions in impulsive choice should be accompanied by reductions in alcohol consumption. However, in the experiment presented in Chapter 2, reductions in impulsive choice for food rewards were accompanied by unexpected increases in alcohol consumption. Accordingly, the goals of the experiments in Chapters 3 and 4 were to help determine the conditions that produced this unexpected finding.

Generally, results of these and other experiments suggest that impulsive choice is not robustly associated with alcohol consumption in rodents, either following experimental manipulation of impulsive choice or under naturally occurring conditions. The work reported here, however, introduces an experimental method of reducing impulsive choice (developed in Chapter 2 and refined in Chapter 4) which may be used in future research to examine the relation between impulsive choice and other drugs of abuse (e.g., cocaine, nicotine).

Checksum

4f41e924daae75bcfd37c2b74c971ffd

Share

COinS