Date of Graduation


Document Type


Degree Type



Eberly College of Arts and Sciences



Committee Chair

Elizabeth Kyonka

Committee Co-Chair

Karen G Anderson

Committee Member

Steven Kinsey


In slot machine play, near wins are losses that are visually similarity to wins and increase gambling persistence, but provide no reinforcer. To measure effects of ethanol on near-win responding, pigeons pecked for food in a slot-machine analog following ethanol administration. In any given trial, one of four outcomes was signaled by consecutive presentations of red or green key lights, followed by a white "collect key." Three red lights signaled a win and three green lights signaled a loss. Two red lights followed by a green light signaled a near win. On winning trials, food was delivered 5 s after presentation of the white collect key, provided there was at least one peck to the collect key while it was illuminated. The probability of pecking the collect key during losing trial types increased as a function of ethanol dose. Response rates did not change systematically as a function of ethanol dose. Pecks to the collect key were allocated more evenly across all trial types at higher alcohol doses. The time to peck the first presentation of a green key did not decrease systematically as a function of dose. These results provide evidence for a decrease in stimulus discrimination between trial types.