About the Lab
The Shahan lab focuses on quantitative analyses of conditioning and learning. The lab regularly uses operant and Pavlovian conditioning procedures with rats and pigeons, including drug and alcohol self-administration procedures. Common topics of investigation are choice, behavioral momentum theory, relapse of extinguished behavior (resurgence, reinstatement, renewal), conditioned reinforcement, and attention. Funding for research in the lab comes from projects examining the implications of quantitative theories of conditioning for problems of human health including drug and alcohol abuse and developmental disabilities.
My laboratory has worked on extending and refining the quantitative approach of Behavioral Momentum Theory for more than a decade. Behavioral Momentum Theory addresses factors that govern the persistence of operant behavior under conditions of disruption. Current theoretical and empirical investigations in my lab are developing and testing new quantitative theories of persistence that overcome a number of shortcomings of Behavioral Momentum that have been identified by our lab and others.
My lab was the first to develop a formal quantitative theory of resurgence. Resurgence is typically defined as an increase (i.e., relapse) of a previously extinguished target behavior when a more recently reinforced alternative behavior is later extinguished. Our original theory of resurgence was an extension of Behavioral Momentum theory. We and others have noted a number of shortcomings of this theory. As a result we have developed a novel choice-based quantitative theory of resurgence. Much current research in my lab is directed at testing the predictions and implications of this new theory.
In recent years my laboratory has been involved making use of basic quantitative theories of behavior to aid in the development of improved Applied Behavior Analysis treatments for problem behavior of children with developmental disabilities . We have conducted basic research with animals to develop and evaluate potential novel treatments involving differential reinforcement of alternative behavior and resurgence following such treatments. We have also collaborated with applied behavior analysts to test the predictions of quantitative theories directly in clinical settings. Current translational research in the lab seeks to evaluate the potential utility of our novel quantitative theory of resurgence for applied settings.
For a number of years my lab has worked to understand and extend the basic conceptual underpinnings of conditioned (i.e., secondary) reinforcement. We have argued that stimuli that have traditionally been called conditioned reinforcers might be better understood as signals that help to guide behavior effectively to important environmental events. We have show that formal application of information theory can provide a way to quantify such a signaling function. Current research in the lab tests the predictions this approach and attempts to examine the generality of the approach by extending it to novel situations (e.g., suboptimal choice situations).
Drug and non-drug sources of reward are well known to interact, and the availability of alternative non-drug sources of reward decreases the choice to take drugs. Treatment approaches using alternative sources of reward (e.g., community reinforcement, contingency management) are highly effective, but are susceptible to relapse when treatment ends and the alternative reinforcers are discontinued. My laboratory extended the resurgence model of relapse to alcohol and drug seeking. In this model, animals are first trained to self-administer drug. Next, drug seeking is reduced via extinction and an alternative source of non-drug food reward is made available for a separate response. Finally, the alternative reward is removed, and drug seeking increases (i.e., resurgence occurs). The current focus of this line of research is to develop procedures for studying resurgence of drug taking that more closely mimic the human condition by reducing drug seeking by other non-extinction means and by arranging non-food alternative reinforcers.
Potential PhD students interested in working with Dr. Shahan should contact him directly by email: Tim.Shahan@usu.edu or fill out the form below.