Kinloch, Jennifer MayFoster, T. MaryMcEwan, James S.A.2010-09-152010-09-152009Kinloch, J.M., Foster, T.M. & McEwan, J.S.A. (2009). Extinction-induced variability in human behavior. The Psychological Record, 59(3), 347-370.https://hdl.handle.net/10289/4573Participants earned points by pressing a computer space bar (Experiment 1) or forming rectangles on the screen with the mouse (Experiment 2) under differential-reinforcement-of-low-rate schedules, followed by extinction. Variability in interresponse time (the contingent dimension) increased during extinction, as for Morgan and Lee (1996); variability in diagonal length (the noncontingent dimension, Experiment 2) did not. In Experiment 3, points were contingent on rectangle size. Rectangle size and interresponse-time (the noncontingent dimension) variability increased in extinction. There was greater variability in the contingent dimension during extinction for participants with the more varied history of reinforcement in Experiment 2 but not in Experiment 3. Overall, variability in the contingent dimension increased in extinction, but the degree of increase was affected by reinforcement history.application/pdfenThis article has been published in the journal: The Psychological Record. Used with permission.psychologyhuman behaviourJournal Article