Association for Behavior Analysis International

Impulsivity is defined as choosing a smaller-sooner reinforcer over a larger-later reinforcer. Impulsivity is positively correlated with a variety of maladaptive behaviors such as overeating, substance abuse, gambling, and risky sexual behaviors. The Kirkpatrick et al. paper will discuss timing-based and delay-tolerance-based interventions which have been used to reduce impulsive choice. In the past, these interventions have been imposed outside the test of impulsive choice. Results will be summarized here which reveal that experience with the test of impulsive choice (itself) improves self-control and delay sensitivity, which may be related to improved interval timing. The remaining two papers in this symposium will summarize the results of two rat experiments evaluating the effects of Pavlovian (vs. Control) training on impulsive choice in rats. In these studies, the CS is used either as an antecedent attractor to the larger-later reward alternative (Mahmoudi et al.), or as a conditioned-reinforcing consequence of making self-control choices (Garland et al.). Preliminary data indicate that these CS-as-antecedent and CS-as-consequence techniques both promote self-controlled choice.

Impulsive choice tasks assess preference for smaller-sooner (indicating impulsive choice) versus larger-later rewards (indicating self-control). Interventions that involve experience with delays promote self-control in impulsive choice tasks in rodents and humans. In some rat studies, the interventions improved timing accuracy and/or precision, which may be one possible mechanism of intervention effects. Another key mechanism that may be targeted by the interventions is delay tolerance, which is the ability to persist through the aversive experience of waiting. These intervention procedures are often presented outside of the choice task. This presentation will discuss recent research assessing whether experience with the impulsive choice task may serve as an intervention by itself. Experience in the choice task improved self-control, increased delay sensitivity, and may be related to the improvements in timing ability reported in previous intervention studies. While the mechanisms of choice-driven improvements in self-control may overlap with intervention-driven improvements, it is possible that choice tasks may be better at targeting timing processes whereas intervention tasks may be better at targeting delay tolerance.

Impulsivity is the preference for smaller, sooner rewards (SSR) over larger, later rewards (LLR), and is correlated with maladaptive behaviors (e.g., gambling). Prior research has explored interventions for reducing impulsivity. One category of learning that has not yet been explored in service of reducing impulsivity is Pavlovian learning. In appetitive Pavlovian learning, a spatially localized conditioned stimulus (CS) that signals a delay-reduction to the unconditioned stimulus (US) will evoke sign-tracking behavior (approaching and interacting with the CS) and will acquire incentive salience. In our study, male Long Evans rats completed Pavlovian training (n = 20) or Control (unpaired) training (n = 20) for 8 sessions; a lever served as the CS. This was followed by an impulsive choice assessment phase. For both groups, the lever-CS was presented on the side of the chamber where the LLR (2 pellets in 20 s) could be obtained. On the other side, the SSR was available (1 pellet after shorter delays). As shown in Figure 1, the lever-CS evoked sign-tracking in Pavlovian-trained rats in the ST group compared to Control rats, and as predicted, when the CS attracted rats to the LLR, they made significantly more self-control choices than Control rats (Figure 2)