i MEMORY AND FRAGMENTATION IN DISSOCIATIVE IDENTITY DISORDER by MARGARET ROSE BARLOW A DISSERTATION Presented to the Department of Psychology and the Graduate School of the University of Oregon in partial fulfillment of the requirements for the degree of Doctor of Philosophy December 2005 ii “Memory and Fragmentation in Dissociative Identity Disorder,” a dissertation prepared by Margaret Rose Barlow in partial fulfillment of the requirements for the Doctor of Philosophy degree in the Department of Psychology. This dissertation has been approved and accepted by: ____________________________________________________________ Dr. Jennifer J. Freyd, Chair of the Examining Committee ________________________________________ Date Committee in Charge: Dr. Jennifer J. Freyd, Chair Dr. Gordon C. N. Hall Dr. Ulrich Mayr Dr. Kathleen Rowe Karlyn Accepted by: ____________________________________________________________ Dean of the Graduate School iii © 2005 Margaret Rose Barlow iv An Abstract of the Dissertation of Margaret Rose Barlow for the degree of Doctor of Philosophy in the Department of Psychology to be taken December 2005 Title: MEMORY AND FRAGMENTATION IN DISSOCIATIVE IDENTITY DISORDER Approved: _______________________________________________ Dr. Jennifer J. Freyd Dissociative identity disorder (DID), formerly called multiple personalities, is a condition in which aspects of experience and memory are separated from each other and from awareness. The current study adds to the literature in this area by utilizing a broad conceptualization of memory functioning in DID, combining ecologically valid memory tests with experimental paradigms, and examining shareability, switching, and integration. Eleven women with DID participated in a two-session experiment that included a variety of memory measures. Participants were given no instructions regarding switching among alters, but were later asked how often they had switched. They reported significantly higher levels of trauma than did a group of 13 female university students. DID participants were faster than student participants at producing autobiographical memories in response to cue words. DID participants also showed a decreased ability to answer detailed questions about a story containing fear, compared with a neutral story. This decrease did not appear in the student group. In a procedural learning task, DID participants improved more than v did the student group on percentage of mirror-reversed words read correctly. Although these results were not statistically significant, effect sizes were moderate to high. Shared and unshared autobiographical memories had similar properties, although in the DID group the unshared memories included significantly more taste imagery than did the shared memories. The student group scored significantly higher on a measure of overall memory than did the DID group. Percentage of alters who knew about the unshared memory was significantly negatively correlated with how long ago the memory was formed. DID participants switched among alters an average of 5.8 times during the memory-testing session, and switching was highly correlated with high levels of lifetime betrayal trauma. This study also introduces the Integration Measure (IM), which is the first standardized measure of integration in DID. Integration was related to switching, though this relationship may be complex. Regression analyses demonstrated that lifetime high betrayal trauma was the best predictor of switching. Frequent switching may also slow reaction time in a variety of tasks. Directions for future research and suggestions for researchers are also discussed. vi CURRICULUM VITAE NAME OF AUTHOR: M. Rose Barlow GRADUATE AND UNDERGRADUATE SCHOOLS ATTENDED: University of Oregon University of Illinois at Urbana-Champaign DEGREES AWARDED: Doctor of Philosophy in Psychology, 2005, University of Oregon Master of Science in Psychology, 2001, University of Oregon Bachelor of Science in Psychology, 2000, University of Illinois at Urbana Champaign AREAS OF SPECIAL INTEREST: Dissociative Identity Disorder Dissociation Memory, Forgetting, and Amnesia Trauma Attachment and Imagination Cognitive Psychology Psychology of Gender PROFESSIONAL EXPERIENCE: Graduate Teaching Fellow, Department of Psychology, University of Oregon, 2000 – 2005. vii GRANTS, AWARDS AND HONORS: American Psychological Association Dissertation Award, 2005 Psychology Department Research Award, University of Oregon, 2004 Graduate School Research Award, University of Oregon, 2004 Psychology Department Travel Award, University of Oregon, 2001 Phi Beta Kappa National Honor Society, 2000 PUBLICATIONS: Barlow, M. R., & Cromer, L. D. (in press). Trauma-relevant characteristics in a university human subjects pool population: Gender, major, betrayal, and latency of participation. Journal of Trauma and Dissociation, Scheduled for Volume 7, Issue 2. Brewer, W. F., Sampaio, C. , & Barlow, M. R. (2005). Confidence and accuracy in the recall of deceptive and nondeceptive sentences. Journal of Memory and Language, 52, 618-627. Goldsmith, R. E., Barlow, M. R., & Freyd, J. J. (2004). Knowing and not knowing about trauma: Implications for therapy. Psychotherapy: Theory, Research, Practice, Training, 41, 448-463. PRESENTATIONS: Brewer, W. F., Sampaio, C., & Barlow, M. R. (2004, November). Confidence and Accuracy for Deceptive and Nondeceptive Semantic Information. Poster session presented at the annual meeting of the Psychonomic Society, Minneapolis, MN. Brewer, W. F., Sampaio, C., & Barlow, M. R. (2003, July). Memory Confidence is Related to Memory Accuracy: Some Evidence from Sentence Recall. Paper presented at the 4th International Conference on Cognitive Science, Sydney, Australia. Sampaio, C., Brewer, W. F., & Barlow, M. R. (2003, July). Confidence and accuracy in sentence recall: Mechanisms and relationships. Paper presented at the meeting of the Society for Applied Research in Memory and Cognition (SARMAC), Aberdeen, Scotland. viii Barlow, M. R., & Freyd, J. J. (2001, November). Implicit, explicit, and procedural memory in high vs. low dissociators. Poster presented at the meeting of the Psychonomic Society, Orlando, FL. Brewer, W. F., Sampaio, C. de A.., & Barlow, M. R. (2001, July). Memory confidence: Mechanisms and memory/accuracy dissociations. Poster presented at the International Conference on Memory, Valencia, Spain. Brewer, W. F., & Barlow, M. R. (2000, November). The relation of memory confidence and memory accuracy. Paper presented at the meeting of the Psychonomic Society, New Orleans, LA. ix ACKNOWLEDGMENTS Funding for this research was provided by a 2005 Dissertation Research Award from the American Psychological Association, a University of Oregon Graduate School Research Award, and a University of Oregon Department of Psychology Graduate Education Committee Award. Thanks to Sara Hodges, fellow late-night worker. Extreme thanks to my adviser, Jennifer J. Freyd, Ph.D. With contacts, ideas, enthusiasm, and unending support and encouragement she made this research possible. Thanks also to Pamela J. Birrell, Ph.D., for years of advice about understanding dissociation, and for recruiting tips. The members of the Dynamics Lab (http://dynamic.uoregon.edu) have provided valuable feedback on several projects— especially Lisa Cromer and Bridget Klest. Thanks to my committee: Jennifer Freyd, Gordon C. N. Hall, Ph.D., Ulrich Mayr, Ph.D., and Kathleen Rowe Karlyn, Ph.D. The University of Oregon Institutional Review Board and Juliana Kyrk were excellent to work with in getting approval for this multi-site study. Further thanks to my collaborators at McLean psychiatric hospital just outside of Boston. It was inspiring to work with James A. Chu, M.D., who provided a wealth of professional knowledge about researching dissociation. Without the tireless efforts of Allison Berger, Ph.D., the project would never have gotten off the ground. Cat Sutherland was instrumental in getting timely approval from the McLean IRB, and JoAnn Graff was also amazing. Thanks! x Undying appreciation goes to Ryan Beasley and Joanna N. Lahey, Ph.D., who let me stay with them rent-free in Cambridge for five weeks while coping with the job market themselves, and who provided pasta, internet, solace, lots of cookies, cats to pet, and an incredibly comfortable bed. Joanna has also proofread everything I’ve written since high school, providing invaluable editing and moral support. Marcia Lucey contributed her professional editing skills to this dissertation – thanks, Mom. Many, many thanks to my great friend Sarah “Chia” Hasler, who graciously took care of my cat for long stretches of time and assorted weekends, often on short notice, so that I could travel to collect data, and who brought me homemade food during my final frantic stretch of writing. And I would never have gotten this far in life without my wonderful partner of ten years, Jared Wadsworth. Thanks for supporting me and for making me laugh! Finally, I thank the participants in this study for sharing their experiences with me. xi TABLE OF CONTENTS Chapter Page I. BACKGROUND AND INTRODUCTION TO DISSOCIATION ...........................1 Definitions of Dissociation .....................................................................................1 Theory of Structural Dissociation ......................................................................3 Neural Network...................................................................................................4 What is DID? ..........................................................................................................6