Date of Award


Degree Name

Master of Science


Behavior Analysis and Therapy

First Advisor

Dixon, Mark


AN ABSTRACT OF THE THESIS OF Katelyn Louise Decker, Master of Science Degree in Behavior Analysis and Therapy, presented on April 30, 2015, at Southern Illinois University TITLE: EFFECTS OF GAMBLING OUTCOMES ON LEVEL OF IMPULSIVITY MAJOR PROFESSOR: Dr. Mark R. Dixon The effects of exposure to winning and losing gambling outcomes on levels of impulsivity among non-gamblers were investigated in a within-subjects experimental design with randomization of treatment phases. Participants included 20 non-gamblers (10 male, 10 female), 18 years or older, selected from a sample of 40 volunteers who completed the South Oaks Gambling Screen (Lesieur & Blume, 1987) and received a score of 0, indicating no predictors of potential pathological gambling. Dependent measures of levels of impulsivity were recorded using an abbreviated version of the delayed discounting questionnaire described by Dixon et al. (2003). Derived k-values were calculated by fitting indifference points at each delay to the hyperbolic equation proposed by Mazur (1987) and average k-value was calculated for each participant across delays. Participants were exposed to both winning and losing outcomes by completing 25 trials within a slot-machine task programmed in Microsoft Visual Basic Express Edition 2008 (Maclin, et al., 2006, p. 127-154). Results were subjected to statistical analysis to determine whether a statistically significant, functional relationship existed between increases and decreases in level of impulsivity (k-value) in comparison to baseline. Across all participants, regardless of order of experimental conditions, results indicated a more than 26% decrease (-82.20-3133.33) in level of impulsivity (0-2.1694) following a losing outcome and a more than 24% decrease (-89.95-3300) in level of impulsivity (0-2.1694) following a winning outcome in comparison to baseline (0-2.3056). Results are consistent with the hypothesis that exposure to winning outcomes decrease impulsivity, but inconsistent with the hypothesis that exposure to losing outcomes increase impulsivity. Historical perspectives of pathological gambling, social impacts of gambling disorder, and trait and state-dependent perspectives of impulsivity are discussed. Potential implications for further research using delayed discounting measures are provided, as well as potential limitations of the present study. Keywords: gambling, impulsivity, delayed discounting, slot-machine, outcomes




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