Does exercise augment operant and Pavlovian extinction: A meta-analysis

BackgroundExposure therapy, a behavioral approach to reduce symptomology in fear, anxiety, and drug-related psychiatric disorders, is based on learning and memory principles of extinction, and is subject to relapse. As such, it is important to find ways to enhance outcomes. One such way is through exercise.ObjectivesIdentify if exercise augments extinction behavior, and whether this depends on the experimental paradigm used (i.e. operant or Pavlovian) and/or stimulus (i.e. appetitive or aversive). Additionally, determine which moderating variables influence the effects of exercise on extinction learning.MethodsA literature search was conducted and a Hedges' g calculation was employed to conduct a meta-analysis (metaSEM) using a structural equation modeling approach. This approach was chosen because of its ability to account for dependencies in effect sizes.ResultsWe found a significant effect of exercise as an augmentation over extinction alone (g = 0.37, p < 0.001), with extinction paradigm (but not stimulus) producing a moderating effect (B = 0.43, p = 0.030). Data were then split by extinction paradigm, with operant extinction models having a significant effect (g = 0.55, p < 0.001), and number of extinction sessions moderating aggregate effects. Pavlovian models did not have significant overall effects (g = 0.11, p = 0.3976), but were moderated by the number of animals housed together and exercise after extinction.ConclusionsThe effects of exercise on extinction learning are differentially modulated by the type of paradigm used, the number of extinction sessions, the timing of when exercise treatment was applied (after extinction), and the housing conditions.