Research Project
10097938
PROJECT SUMMARY Steeply devaluing future consequences is robustly correlated with substance abuse and other addictive disorders. Preventing these disorders might be achieved by improving the individual?s ability to delay gratification, to tolerate delays, and thereby to make fewer impulsive choices. Several labs have sought to develop learning- based interventions designed to reduce impulsive choice. Our lab has pioneered one such method ? delay- exposure training ? which has been rigorously demonstrated to produce large and lasting reductions in rats? impulsive choices. While exploring what rats learn during delay-exposure training, we discovered that their tolerance of delay-signaling stimuli was superior to that of control-group rats. That is, when rats were given an opportunity to press a lever to turn off a stimulus signaling a delay to a large food-reward, delay-exposure trained rats rarely turned it off. By contrast, control-group rats frequently turned off the delay-signaling stimulus, thereby demonstrating that, to them, the stimulus was aversive. A similar aversion to delay-signaling stimuli is observed among children diagnosed with ADHD, and signaled delays can induce problem behavior in children in school settings. The proposed research will capitalize on our finding by doing more than just making the delay-signaling stimulus less-aversive. We propose to make that stimulus a conditioned reinforcer prior to the test of impulsive choice. Pavlovian methods for accomplishing this are well established, but no prior experiments seeking to therapeutically reduce impulsive choice have employed these methods. The project has two aims. First, to evaluate the relative short- and long-term efficacy of Pavlovian training, delay-exposure training, and a combination of these training techniques; all groups compared to a control group. Second, to evaluate the contribution of Pavlovian processes to the changes in impulsive choice. This will be accomplished by manipulating a variable which impacts Pavlovian learning (the C/t ratio). Because Pavlovian learning occurs rapidly under optimal conditions (i.e., large C/t ratios) we expect Pavlovian training to prove more efficient and more effective in reducing impulsive choice than delay-exposure training. Such findings will speed the pace of discovery in the lab, and will have translational implications for resiliency building prevention-programs designed to reduce human impulsivity. Importantly, the findings will be used as preliminary data supporting nonhuman and human research exploring these basic and translational implications.
