A Randomized Controlled Trial of Mindfulness Meditation (Samatha) As A
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IMPROVING COGNITION IN NORMALLY AGING OLDER ADULTS: A RANDOMIZED CONTROLLED TRIAL OF MINDFULNESS MEDITATION (SAMATHA) AS A TREATMENT FOR ATTENTIONAL INHIBITORY DEFICITS Presented to The Graduate Faculty of The University of Akron In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Jeanette S. Biermann August, 2011 IMPROVING COGNITION IN NORMALLY AGING OLDER ADULTS: A RANDOMIZED CONTROLLED TRIAL OF MINDFULNESS MEDITATION (SAMATHA) AS A TREATMENT FOR ATTENTIONAL INHIBITORY DEFICITS Jeanette S. Biermann Dissertation Approved: Accepted: ________________________ ________________________ Advisor Department Chair James R. Rogers, Jr., PhD Karin Jordan, PhD ________________________ ________________________ Committee Member Dean of the College Paula Hartman-Stein, PhD Mark D. Shermis, PhD ________________________ ________________________ Committee Member Dean of the Graduate School Kevin P. Kaut, PhD George R. Newkome, PhD ________________________ ________________________ Committee Member Date John E. Queener, PhD ________________________ Committee Member Charles A. Waehler, PhD ii ABSTRACT According to Hasher and Zacks's (1988) Inhibitory Deficit Theory (IDT), a decline in the ability to inhibit task-irrelevant information from grabbing one's attention is the underlying cause for age- related differences in cognitive abilities. Unlike some other theories of cognitive aging, IDT provides a leverage point available to older adults for a low-cost, non-pharmaceutical intervention that could prevent or at least slow the decline in cognitive functioning with age: attentional functioning, or more specifically, inhibitory attentional functioning. This study investigated the efficacy of attentional process training in the form of meditation (samatha) on the neuropsychological functioning of cognitively intact older adults. Forty-two community dwelling adults (average age 73 years) participated in a 4-week, randomized wait-list-controlled clinical trial. Compliance with twice-weekly attendance and at-home practice, and a self-evaluation of achievement at the end of the training indicated that older adults can and will learn samatha. Objective efficacy measures consisted of participants' change scores on the Trail Making Test (TMT) and the Reading-with-Distraction Task (RwDT) from pretreatment baseline to assessment after completion of the experimental group's samatha training. The Attention-Related Cognitive Errors Scale (ARCES) and the Everyday Memory Failures Scale (MFS) were used as subjective measures. Improvement on the RwDT was statistically significant ( d = .75), suggesting that the intervention had a beneficial effect on inhibitory attentional functioning. Improvement on TMT-B (d = .40) did not reach statistical significance. Hence the study failed to provide strong evidence that the 4-week intervention could effect improvement in cognitive functioning beyond attention. MFS and ARCES change scores had small, statistically non-significant improvements, indicating that, on average, participants did not perceive improvement in their memory and attentional functioning. Implications for practice and further research and the study's strengths and limitations are discussed. iii ACKNOWLEDGEMENTS Conducting research and producing a dissertation are not solo acts, and I am grateful to all those who generously helped me along the way. Thank you, Dr. James Rogers, my advisor, for discussing ideas and guiding me to a successful conclusion. Thanks also to my committee members Drs. Kevin P. Kaut, John Queener, and Charles Waehler, for the excellent training you provided to me as professors, for the high standards for research you uphold, and for your commitment to this study. I am especially appreciative of all that Dr. Paula Hartman-Stein has done for me, not only serving on my committee but long before that for the clinical supervision, career guidance, the many professional opportunities she has extended to me, her realism, and her friendship. I was fortunate to have encountered so many benevolent people as I conducted the experiment. Thank you to: Carmelina Barbera at the Avon Senior Center whose enthusiastic response to my project and "intel" on other senior centers was so encouraging when I began recruiting; Regina Sillacen and Cathy Eble at the Fairview Park Senior Center, who were so warmly welcoming as I began to execute the project; Margaret Allen, who managed to accommodate me at the very heavily scheduled Rocky River Senior Center; and to all of the men and women who were study participants and who gave so much of their time for testing, training, group discussion, and practice, and who I hope will continue to use the techniques I taught them. Most of all I must acknowledge the love and support of my husband and the many sacrifices he made for all the years I have been pursuing this degree. iv TABLE OF CONTENTS Page LIST OF TABLES ...................................................................................................................... viii LIST OF FIGURES..................................................................................................................... ix CHAPTER I. STATEMENT OF THE PROBLEM........................................................................................... 1 II. LITERATURE REVIEW .......................................................................................................... 6 Attention ............................................................................................................................... 7 Inhibitory Deficit Theory ...................................................................................................... 12 Conventional Approaches To Improving Attention ............................................................... 30 Meditation As Mental Process Training ............................................................................... 40 Evidence That Meditation Affects Cognition ........................................................................ 50 Summary ............................................................................................................................ 71 Research Hypotheses ......................................................................................................... 73 III. METHODOLOGY ................................................................................................................ 74 Research Design ................................................................................................................ 74 Participants ......................................................................................................................... 75 Instrumentation ................................................................................................................... 77 Procedures ......................................................................................................................... 90 Statistical Hypotheses And Analysis .................................................................................... 98 v IV. RESULTS ......................................................................................................................... 101 Participants' Response To The Training Intervention ......................................................... 101 Improvement In Ability To Inhibit Distractions .................................................................... 102 Improvement In Cognition ................................................................................................. 103 Improvement In Self-Perception Of Memory Functioning ................................................... 105 Improvement In Self-Perception Of Attentional Functioning ............................................... 106 Results Summary ............................................................................................................. 108 V. DISCUSSION .................................................................................................................... 109 Findings ............................................................................................................................ 110 Strengths And Limitations ................................................................................................. 116 Implications For Future Research ..................................................................................... 119 Implications For Practice ................................................................................................... 120 REFERENCES ....................................................................................................................... 122 APPENDICES ......................................................................................................................... 135 APPENDIX A. RwDT SAMPLES ...................................................................................... 136 APPENDIX B. INFORMED CONSENT ............................................................................. 138 APPENDIX C. PARTICIPATION AGREEMENT ............................................................... 140 APPENDIX D. DEMOGRAPHIC AND CONTACT DATA .................................................. 141 APPENDIX E. TRAIL MAKING TEST (TMT) .................................................................... 142 APPENDIX F. TRAIL MAKING TEST (TMT) ALTERNATE FORMS .................................. 146 APPENDIX G. READING WITH DISTRACTION TASK (RwDT) .......................................