Date of Award:


Document Type:


Degree Name:

Master of Science (MS)



Committee Chair(s)

Michael P. Twohig


Michael P. Twohig


Timothy A. Shahan


Gregory J. Madden


Behavioral and cognitive-behavioral psychotherapies utilizing exposure are considered the gold standard in anxiety disorder treatments. Despite their success, relapse remains problematic, especially over long-term follow up periods. Basic researchers traditionally conceptualize the mechanism of exposure as Pavlovian extinction, but this may overlook the important role of operant processes in the treatment and relapse of anxiety. Resurgence, in which a previously extinguished behavior returns following the extinction of another behavior that has replaced it, is a promising model of operant relapse. Nonhuman research on resurgence has shown that, while higher rates of alternative reinforcement result in faster and more comprehensive extinction of target behavior, they also result in greater resurgence. This somewhat paradoxical finding could have important implications for clinicians treating anxiety, as higher rates of alternative reinforcement may have the unintended side effect of producing greater relapse of avoidance if access to positive reinforcement later becomes unavailable. The current study took a translational approach to investigating the effects of rich and lean rates of alternative reinforcement on extinction and magnitude of resurgence in typically developing humans using a computerized task. Three groups (Rich, n = 18; Lean, n = 18; Control, n = 10) underwent acquisition of a target response. Target responding was then placed on extinction while varying rates of reinforcement for an alternative behavior were delivered. Resurgence was assessed under extinction conditions for all groups. Results indicated that the rich rate of alternative reinforcement facilitated extinction while the lean rate ultimately had a detrimental effect on extinction. Within groups, Rich and Lean experienced significant resurgence, while Control did not. Effect sizes were large. Between groups, Rich resurged more than Lean and Control. Effect sizes were again large. There was no significant difference in resurgence between Lean and Control. Implications for the treatment of anxiety disorders and future research directions are discussed.