Date of Award


Degree Name

Master of Arts



First Advisor

Dr. Alan D. Poling

Second Advisor

Dr. Jack Michael

Access Setting

Masters Thesis-Open Access


Although the progressive-ratio (PR) schedule has been used frequently to quantify the reinforcing effectiveness of self-administered drugs, it has seldom been used to examine the effects of drugs on food-maintained behavior and has never been used to evaluate the effects of cocaine on such behavior. In the present study, the effects of acute administrations of cocaine were evaluated in pigeons responding under a PR schedule of food delivery. Overall, cocaine produced a dose-dependent effect on food-maintained behavior. In general, acute administrations of cocaine at 0.56 to 3.2 mg/kg increased breaking points, whereas doses above 5.6 mg/kg decreased breaking points. Low doses of cocaine slightly increased the rate of responding in most of the subjects. Higher doses decreased response rates in generally dose-dependent fashion. Although cocaine reduces food intake and subjective hunger for food, the present data indicate that the drug reduces the reinforcing effectiveness of food only at high doses.