Cerebellum-Seeded Functional Connectivity Changes in Trait-Anxious Individuals Undergoing Attention Bias Modification Training
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Northern Michigan University NMU Commons All NMU Master's Theses Student Works 7-2021 CEREBELLUM-SEEDED FUNCTIONAL CONNECTIVITY CHANGES IN TRAIT-ANXIOUS INDIVIDUALS UNDERGOING ATTENTION BIAS MODIFICATION TRAINING Katherine Elwell [email protected] Follow this and additional works at: https://commons.nmu.edu/theses Part of the Behavioral Neurobiology Commons, Biological Psychology Commons, Clinical Psychology Commons, Cognitive Neuroscience Commons, Cognitive Psychology Commons, Mental Disorders Commons, Psychiatric and Mental Health Commons, and the Psychological Phenomena and Processes Commons Recommended Citation Elwell, Katherine, "CEREBELLUM-SEEDED FUNCTIONAL CONNECTIVITY CHANGES IN TRAIT-ANXIOUS INDIVIDUALS UNDERGOING ATTENTION BIAS MODIFICATION TRAINING" (2021). All NMU Master's Theses. 676. https://commons.nmu.edu/theses/676 This Open Access is brought to you for free and open access by the Student Works at NMU Commons. It has been accepted for inclusion in All NMU Master's Theses by an authorized administrator of NMU Commons. For more information, please contact [email protected],[email protected]. CEREBELLUM-SEEDED FUNCTIONAL CONNECTIVITY CHANGES IN TRAIT- ANXIOUS INDIVIDUALS UNDERGOING ATTENTION BIAS MODIFICATION TRAINING By Katherine A. Elwell THESIS Submitted to Northern Michigan University In partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN PSYCHOLOGICAL SCIENCE Office of Graduate Education and Research July 2021 i ABSTRACT CEREBELLUM-SEEDED FUNCTIONAL CONNECTIVTY CHANGES IN TRAIT- ANXIOUS INDIVIDUALS UNDERGOING ATTENTION BIAS MODIFICATION TRAINING By Katherine A. Elwell Anxiety and anxiety related disorders are increasing at a drastic rate in the past decade, with the NIMH reporting that 31.1% of U.S. adults will experience an anxiety disorder at some point in their lives. Anxiety is commonly characterized by increased attention bias to threat. Attention Bias Modification (ABM) is a new treatment used to reduce individual’s attention bias towards threat. The extent to which ABM leads to underlying neural changes is still unknown. The cerebellum is a neglected brain structure, with new research provides evidence that cerebellum’s functional connectivity and shared networks with threat processing regions has a direct impact on anxiety etiology and symptomology. Therefore, the current study assessed functional connectivity changes seeded in cerebellum as an outcome of ABM training. The experiment consists of a 6-week ABM or control training period bookended by pre and post resting state functional magnetic resonance imaging (rsfMRI) sessions. Heightened trait anxiety was correlated with heightened connectivity from the cerebellum to threat processing regions. (i.e., the amygdala, ACC, and the thalamus). Decreased cerebellar connectivity to threat processing regions (i.e., the amygdala, ACC, and the thalamus) was observed following ABM training. This suggests that ABM may underlie neural changes within the cerebellum—resulting in decreased attention bias. This also suggests the cerebellum may contribute to the etiology and maintenance of anxiety and attention bias. Limitations and future directions concerned with both ABM and the functional role of the cerebellum are discussed. iii Copyright by Katherine A. Elwell 2021 iv DEDICATION This thesis is dedicated to my parents, Amy Elwell (Rink) and Rom Elwell, as well as my twin brother William Elwell, my younger sister Emma Elwell, and my very close friends and family. These individuals have supported me tremendously thought my academic and personal endeavors—I would not be where I am today without them. This thesis is also dedicated to all individuals inflicted with anxiety and anxiety disorders. It is my hope that my research can provide further contributions into the etiology of anxiety disorders. v ACKNOWLEDGEMENTS The author wishes to thank her graduate advisor, mentor, and director of the CABIN Lab, Dr. Joshua M. Carlson who provided guidance and insight throughout this project as well as other aspects of her graduate endeavors. She also would to thank Dr. Lin Fang, the co-director of the CABIN Lab, for all of the guidance and patience she generously gave throughout this project. The author would also like to thank her final committee member, Dr. Christina Hartline, for all of her feedback and support related to this project and the realm of clinical psychology. Additionally, the author would like to thank fellow undergraduate and graduate students of the CABIN Lab for their help in recruiting participants, collecting data, and progress monitoring during the long nature of this study. Particularly, the author wishes to thank Sydney Climie, Cassidy Girard, and Hayley Gilbertson of the CABIN Lab for not only aiding in aspects of this experiment, but also, for keeping the sanity of the author in check throughout the duration of this thesis. The author also wishes to thank her other very close friends, Katherine Aber, Xochitl Delgado, Shelbie Marble, and Alexandria Merchant for all of their continuous love and support. Additionally, the author would like to thank the National Institute of Mental Health for funding this project under the research grant R15MH1109051 awarded to Dr. Carlson. This thesis follows the format prescribed by the Publication manual of the American th Psychological Association, 7 edition and the Department of Psychological Science. vi TABLE OF CONTENTS ABSTRACT ............................................................................................................................... (iii) COPYRIGHT ............................................................................................................................. (iv) DEDICATION ............................................................................................................................ (v) ACKNOWLEDGEMENTS ....................................................................................................... (vi) TABLE OF CONTENTS .......................................................................................................... (vii) LIST OF FIGURES ..................................................................................................................... (x) LIST OF TABLES ......................................................................................................................(xi) INTRODUCTION ......................................................................................................................... 1 LITERATURE REVIEW .............................................................................................................. 3 Anxiety and Fear............................................................................................................... 3 Attention Bias Modification............................................................................................. 7 Models of Attention Bias ................................................................................................. 8 Neural Correlates of Attention Bias in Anxiety .......................................................... 12 The Cerebellum ...............................................................................................................13 RATIONALE ............................................................................................................................... 19 METHODS .................................................................................................................................. 20 Participants ..................................................................................................................... 20 General Procedure ......................................................................................................... 21 Screening ......................................................................................................................... 21 Questionnaires .................................................................................................... 21 Dot Probe Task..................................................................................................... 23 Analysis ........................................................................................................................... 26 vii RESULTS .................................................................................................................................... 28 DISCUSSION .............................................................................................................................. 31 Measures of trait-anxiety and attention bias pre and post training .......................... 31 Hypothesis one: Heightened Trait Anxiety and Increased Cerebellum rsFC........... 34 Trait-Anxiety and Increased Cerebellum-Thalamus rsFC................................ 36 Trait-Anxiety and Increased Cerebellum-Frontal Gyrus rsFC......................... 37 Trait-Anxiety and Increased Cerebellum-Insula rsFC...................................... 38 Trait-Anxiety and Increased Cerebellum-ACC rsFC......................................... 39 Trait-Anxiety and Increased Cerebellum-Precentral Gyrus rsFC..................... 40 Trait-Anxiety and Increased Cerebellum-Salience Network rsFC.................... 41 Hypothesis two: Decreased Cerebellum rsFC Following ABM Training ................. 43 Cerebellum-ACC rsFC Decreases Following ABM........................................... 44 Cerebellum-Amygdala rsFC Decreases Following ABM.................................