UNIVERSITY of CALIFORNIA Los Angeles Top-Down
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UNIVERSITY OF CALIFORNIA Los Angeles Top-Down and Bottom-Up Fear Regulation: Experimental Combinations to Reduce the Return of Fear and an Examination of its Neural Correlates A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in Psychology by Michael Sun 2019 © Copyright by Michael Sun 2019 ABSTRACT OF THE DISSERTATION Top-Down and Bottom-Up Fear Regulation: Experimental Combinations to Reduce the Return of Fear and an Examination of its Neural Correlates by Michael Sun Doctor of Philosophy in Psychology University of California, Los Angeles, 2019 Professor Michelle Craske, Chair The regulation of fear can be considered as driven from stimulus properties, considered bottom-up, and cognitive constructions, considered top-down. This dissertation contains three papers that investigated how these approaches may complement one another for the purposes of clinical translation to optimize long-term fear amelioration in treatments for fear-related disorders. In Study 1, a fear-conditioning experiment was conducted manipulating the use of a low- cost, re-evaluative, and contingency-directed cognitive reappraisal against passive and active control conditions (i.e., react-as-normal and expressive suppression). The experiment examined how this strategy changed responses during extinction training and during a test of rapid reacquisition one-week later. In Study 2, the experiment was replicated twice. The first replaced ii the test of rapid reacquisition with an induction of fear reinstatement. The second replaced the test of rapid reacquisition with an induction of context renewal. Results indicated that reappraisal led to faster reductions in threat expectancy to the CS- during extinction training relative to suppression. This was not observed when extinction training featured CSs overlaid atop visual contexts. Results also indicated that in one of three experiments, reappraisal, relative to reacting as normal, led to increases in CS+ valence after extinction training and reductions in the spontaneous recovery of skin conductance responses. Reappraisal, relative to suppression, also led to faster recovery of CS+ US expectancy after fear reinstatement. Suppression led to greater skin conductance responding to the CS- relative to reappraisal and reacting as normal during rapid reacquisition and greater skin conductance responding to the CS+ during context renewal relative to reacting as normal. Study 3 examined how individuals who express above average spontaneous recovery in skin conductance responses differentially recruit neural activity in structures that putatively implement fear (amygdala, BNST, anterior insula), top-down regulation (dlPFC and vlPFC) and bottom-up regulation (vmPFC and sgACC) during a test of spontaneous recovery 24-48 hours after fear extinction training. Results suggested sparse evidence for fear over-generation in fear regions, and more evidence for misregulation, underregulation/disconnection, and competitive co-regulation in regions that implement fear regulation. Results are discussed in terms of the granular mechanisms underlying extinction and cognitive reappraisal, and implications for clinical application. iii The dissertation of Michael Sun is approved. Hakwan Lau Jennifer Silvers Annette Stanton Michelle Craske, Committee Chair University of California, Los Angeles 2019 iv Dedication To Eli Olivia Sun, my daughter, and Stephanie Sun, my wife, my shining lights. v Table of Contents Abstract of the Dissertation ............................................................................................................ ii Approval. ....................................................................................................................................... iv Dedication ....................................................................................................................................... v List of Figures and Tables............................................................................................................ viii Acknowledgements ........................................................................................................................ ix Vita .................................................................................................................................................. x General Introduction ....................................................................................................................... 1 Bottom-up Emotion Regulation through Conditional Learning ................................................. 2 Context-Free Return of Fear ....................................................................................................... 4 Context-Based Return of Fear ..................................................................................................... 5 Top-Down Emotion Self-Regulation .......................................................................................... 6 An Integrative Computational Approach .................................................................................... 7 Neurobiological Support ............................................................................................................. 7 Overview of Studies .................................................................................................................... 8 Study 1: The Effects of Emotion Regulation on the Spontaneous Recovery of Conditional Fear and its Rapid Reacquisition .......................................................................................................... 10 Abstract ..................................................................................................................................... 11 Introduction ............................................................................................................................... 12 Methods ..................................................................................................................................... 14 Results ....................................................................................................................................... 20 Discussion ................................................................................................................................. 25 Study 2: The Effects of Emotion Regulation on Reinstatement and Context-Renewal of Fear ... 31 Abstract ..................................................................................................................................... 32 Introduction ............................................................................................................................... 33 Methods ..................................................................................................................................... 35 Study 1. Reinstatement .............................................................................................................. 39 Results ................................................................................................................................... 41 Discussion .............................................................................................................................. 45 Study 2. Context Renewal ......................................................................................................... 46 Results ................................................................................................................................... 48 vi Discussion .............................................................................................................................. 52 Conclusion ................................................................................................................................. 53 Study 3: Neural Correlates of Fear Spontaneous Recovery and its Regulation ........................... 62 Abstract ..................................................................................................................................... 63 Introduction ............................................................................................................................... 64 Methods ..................................................................................................................................... 69 Results ....................................................................................................................................... 77 Discussion ................................................................................................................................. 90 Conclusion ................................................................................................................................. 97 General Discussion ..................................................................................................................... 102 Clinical Research and Translation........................................................................................... 109 References ................................................................................................................................... 112 vii List of Figures and Tables 1. General Introduction a. Figure 1 (page 5) 2. Study 1 a. Figure 1 (page 17) b. Figure 2 (page 29) c. Figure 3 (page 30) 3. Study 2 a. Figure 1 (page 40) b. Figure 2 (page 47) c. Figure 3 (page 58) d. Figure 4 (page 59) e. Figure 5 (page 60) f. Figure 6 (page 61)