Stimulus Control and Generalization of Operant Variability in the Block
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Stimulus Control and Generalization of Operant Variability in the Block Play of Children with Autism Dissertation Presented in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in the Graduate School of The Ohio State University By Neal Douglas Miller, M.S.Ed., BCBA Graduate Program in Education The Ohio State University 2012 Dissertation Committee: Dr. Nancy A. Neef, Advisor Dr. William L. Heward Dr. Helen I. Cannella-Malone Dr. Ralph Gardner, III Copyright by Neal Douglas Miller 2012 Abstract Children with autism have a tendency to engage in repetitive behaviors across multiple domains, including play. One method for decreasing repetitive behavior that has been studied in humans and other animals in both laboratory and applied settings is the explicit reinforcement of variability. Basic research suggests that varied responding can be brought under the control of an antecedent stimulus that reliably predicts the availability of reinforcement for variability. The purpose of this study was to examine the effects of a lag 3 schedule on the diversity of forms constructed during block play by children with autism. In addition, the study evaluated the effects of a procedure designed to establish stimulus control over repetition and variation, and examined the extent to which variability would generalize to a novel task in which the same discriminative stimuli were presented. Three boys diagnosed with autism, ages 7 to 9, served as participants. All three lacked appropriate play skills. During daily sessions, the experimenter presented the students with materials to either build block structures or create patterns on a pegboard. Variability was defined as the degree to which the forms created varied from one another. In an initial continuous reinforcement (CRF) phase, any form that the students created resulted in reinforcement. In a subsequent variability (VAR) phase, the experimenter asked the participant to make something “different,” and then reinforced only the creation ii of forms that were different from the previous three that were built (a lag 3 schedule). After this, students experienced a repeat (REP) phase in which they were instructed to make “the same,” and only forms that repeated one of the three most recently produced resulted in reinforcement (a rep 3 schedule). After experiencing multiple reversals between these two phases, an alternating schedule (ALT) phase was introduced in which each trial was determined by a random sequence to operate on either the VAR or REP contingencies, and the discriminative cues (“same” and “different”) were presented on each trial. An Sd absent (SDA) phase in which the discriminative cues were removed followed this. Finally, students were exposed to a novel task (painting a series of squares) in which the same cues were used. A reversal design was employed to compare the effects of these schedules on response variability. All three participants increased the diversity of block forms produced under the lag 3 schedule. All three participants also demonstrated evidence of stimulus control in that responding varied more under the VAR component of the multiple schedule in the ALT phase, but the two conditions did not have the same effect when the discriminative stimuli were absent during the SDA phase. During the generalization task, students did not demonstrate stimulus control, in that the sequences of colors produced were equally likely to vary whether students were asked to make “same” or “different.” The implications of these findings for the education of children with autism are discussed, along with suggestions for future research directions. iii Dedication To my wife Melissa, and my son Elliott, who have supported me in every way possible during this process. To my mother, Paula Miller, for her selfless generosity throughout my life. And, to the memory of my father, David Miller, who gave me everything. “Does the poet create, originate, initiate the thing called a poem, or is his behavior merely the product of his genetic and environmental histories?" B.F. Skinner iv Acknowledgments I would like to acknowledge Allen Neuringer, who advised me as an undergraduate at Reed College years ago. I don’t even know what I would be doing today if it weren’t for the influence he’s had on me. In those psychology classes I took with him, I discovered a passion for behaviorism that has since become an inextricable part of who I am. Over the years he has always been there when I’ve needed him, and has pushed me to pursue my dreams. Allen’s research and writings still inspire and amaze me, and I truly cherish his generous feedback and advice over the years. I am very lucky to have a mentor of his caliber in my life. I also want to express the deepest gratitude to my advisor, Nancy Neef, who has had faith in me throughout this process, and contributed immeasurably to my growth as a scientist. She has been everything I could have wanted in an advisor, and I can only hope that I will be able to live up to her example in my life. In the last three years, she has provided me with a level of guidance, encouragement and support that I never imagined possible. She has not only given me the tools I am going to need as a researcher and teacher, but also helped me to believe in myself. I will be forever in her debt. I want to thank my dissertation committee, Dr. William Heward, Dr. Helen Canella-Malone, Dr. Ralph Gardner, and Dr. Nancy Neef for supporting this crazy idea I had, and allowing me to pursue it to its conclusion. Each of you contributed to my formulation of this dissertation. v I also want to acknowledge Dr. Morten Haugland for his encouragement and his invaluable support of my efforts. Finally, I want to thank all of the students who I have worked side by side with during the development and execution of this research, especially James Meindl, Jonathan Ivy, Joshua Garner, and Jessica Heacock. I am indebted to each of you for your assistance and kindness. vi Vita 1997................................................................B.A. Psychology, Reed College 1999–2000......................................................Behavior Technician, Developmental Systems Inc., Portland, OR 2002–2005......................................................Program Manager, Behavioral Consulting Group, Inc., Portland, OR 2005–2007......................................................Lead Therapist, Children’s Evaluation Center, Boston, MA 2007................................................................M.S.Ed. Behavioral Education, Simmons College 2007–2009......................................................Behavioral Consultant, Self-Employed, Portland, OR 2009–present ..................................................Graduate Teaching Associate, The Ohio State University Publications Miller, N., & Neuringer, A. (2000). Reinforcing variability in adolescents with autism. Journal of Applied Behavior Analysis, 33, 151–165. Perrin, C., Miller, N., Haberlin, A. T., Ivy, J. W., Meindl, J. N., & Neef, N. A. (2011). Measuring and reducing college students’ procrastination of studying. Journal of Applied Behavior Analysis, 44, 463–474. vii Fields of Study Major Field: Education Specialization: Applied Behavior Analysis Special Education viii Table of Contents Abstract ............................................................................................................................... ii Dedication .......................................................................................................................... iv Acknowledgments............................................................................................................... v Vita .................................................................................................................................... vii Publications ....................................................................................................................... vii Fields of Study ................................................................................................................. viii Table of Contents ............................................................................................................... ix List of Tables .................................................................................................................... xv List of Figures .................................................................................................................. xvi Chapter 1: Introduction ...................................................................................................... 1 Operant Variability ...................................................................................................... 3 Variability and Autism ................................................................................................ 5 Generalization of Operant Variability ......................................................................... 6 Purpose of Paper .......................................................................................................... 7 Chapter 2: Literature Review .............................................................................................. 9 Defining and Measuring Variability ............................................................................ 9 ix Measures of dispersion ...................................................................................... 10 Equiprobability and U-value .............................................................................