Changing Nonhuman Impulsive Choice

Preference for smaller-sooner over larger-later rewards characterizes one type of impulsivity—impulsive choice. Impulsive choice is related to a number of maladaptive behaviors including substance abuse, pathological gambling, and poor health behaviors. As such, interventions designed to reduce impulsive choice may have therapeutic benefits. The purpose of this dissertation was to explore two methods to change nonhuman impulsive choice. In doing so, we hope to provide a baseline that future research can use to assess variables that are less amenable to human research (e.g., drug self-administration following reductions in impulsive choice). In Chapter 2, we failed to reduce nonhuman impulsive choice using working-memory training, a finding both inconsistent and consistent with the extant human literature. Chapters 3-5 sought to better understand a training regimen that generates large between-group differences in nonhuman impulsive choice—delay- and immediacy-exposure training. The results from Chapters 3 and 4 suggest that prolonged exposure to delayed food rewards produces large and long-lasting reductions in impulsive choice. Chapter 5 showed that the delay-exposure training effect can be obtained in fewer sessions than has previously been employed. A better understanding of the effects of delay-exposure training on nonhuman impulsive choice may have implications for the design and implementation of a human analog