Exploration of Near-Death Experience Accounts Helena Cassol Under the supervision of Prof. Steven Laureys Thèse présentée en vue de l’obtention du grade de Docteur en Sciences biomédicales et pharmaceutiques Supervisor Prof. Steven Laureys, MD, PhD, Université de Liège Assessment committee Prof. Didier Ledoux (president), MD, PhD, Université de Liège Dr Charlotte Martial (secretary), PhD, Université de Liège Prof. Axel Cleeremans, PhD, Université Libre de Bruxelles Dr François Lallier, MD, PhD, Université de Reims Dr Arnaud D’Argembeau, PhD, Université de Liège Dr Athena Demertzi, PhD, Université de Liège Dr Olivia Gosseries, PhD, Université de Liège Cover design: © Helena Cassol, 2019 Original drawing by Roberto Cassol This research was supported by the University and University Hospital of Liege, the Belgian National Funds for Scientific Research (FRS-FNRS), the European Union’s Horizon 2020 Framework Programme for Research and Innovation under the Specific Grant Agreement No. 785907 (Human Brain Project SGA2), the Luminous project (EU-H2020-fetopenga686764), the European Space Agency (ESA) and the Belgian Federal Science Policy Office (BELSPO) in the framework of the PRODEX Programme ,the Center-TBI project (FP7-HEALTH- 602150), the Public Utility Foundation ‘Université Européenne du Travail’, “Fondazione Europea di Ricerca Biomedica”, the Bial Foundation, the Mind Science Foundation, personal travel grants from the University of Liège (MODUS) and the European Commission. I dedicate this thesis to all the near-death experiencers who have shared their experience with our team: This work could not have been done without you. Table of Contents Scientific publications ..................................................................................................... vii List of abbreviations ...................................................................................................... xiii Abstract .......................................................................................................................... xv Résumé ......................................................................................................................... xvii 1 Introduction .............................................................................................................. 1 1.1 Description of the phenomenon ......................................................................... 2 1.2 Common features reccurring in near-death experiences ................................... 9 1.3 Identification of near-death experiences ..........................................................13 1.4 Near-death like experiences ..............................................................................18 1.5 Resulting memory .............................................................................................21 1.6 Characteristics of near-death experiencers ......................................................24 1.7 Distressing near-death experiences ..................................................................33 1.8 Theoretical approaches to near-death experiences .........................................36 1.9 Impact of near-death experiences ....................................................................44 1.10 Overview of the present work ........................................................................56 2 Exploring the content of pleasant and distressing near-death experiences ..........59 2.1 Study 1. Thematic analysis of near-death experiences accounts ...................60 2.1.1 Summary .....................................................................................................60 2.1.2 Introduction ................................................................................................61 2.1.3 Materials and methods...............................................................................63 2.1.4 Results ........................................................................................................70 2.1.5 Discussion ...................................................................................................77 2.2 Study 2. Distressing near-death experience accounts .....................................83 2.2.1 Summary .....................................................................................................83 2.2.2 Introduction ................................................................................................84 2.2.3 Materials and methods...............................................................................87 v 2.2.4 Results ........................................................................................................91 2.2.5 Discussion ...................................................................................................99 3 Near-death experience memories: Self-defining memories with flashbulb-like features? .......................................................................................................................103 3.1 Study 3. Are near-death experience memories self-defining? ......................104 3.1.1 Summary ...................................................................................................104 3.1.2 Introduction ..............................................................................................105 3.1.3 Materials and Methods ............................................................................108 3.1.4 Results ......................................................................................................114 3.1.5 Discussion .................................................................................................120 3.2 Study 4. Near-death experience memories include more episodic and non- episodic components than flashbulb memories .....................................................125 3.2.1 Summary ...................................................................................................125 3.2.2 Introduction ..............................................................................................126 3.2.3 Materials and Methods ............................................................................130 3.2.4 Results ......................................................................................................135 3.2.5 Discussion .................................................................................................145 4 Neurochemical models of near-death experiences ..............................................151 4.1 Study 5. A large scale study based on the semantic similarity of written reports ......................................................................................................................152 4.1.1 Summary ...................................................................................................152 4.1.2 Introduction ..............................................................................................153 4.1.3 Materials and methods.............................................................................157 4.1.4 Results ......................................................................................................164 4.1.5 Discussion .................................................................................................178 5 Conclusion and perspectives ................................................................................191 6 References ............................................................................................................207 vi Scientific publications The present thesis is based on the following publications: Articles: Cassol, H., Bonin, E. A. C., Bastin, C., Puttaert, N., Charland-Verville, V., Laureys, S., & Martial, C. (in preparation). Near-death experience memories include more episodic and non-episodic components than flashbulb memories. Cassol, H., D’Argembeau, A., Charland-Verville, V., Laureys, S.*, & Martial, C* (contributed equally). (2019). Memories of near-death experiences: are they self- defining? Neuroscience of Consciousness, 5(1), 1-9. Cassol, H., Martial, C., Annen, J., Martens, G., Charland-Verville, V., Majerus, S., & Laureys, S. (2019). A systematic analysis of distressing near-death experience accounts. Memory, 1–8. Cassol, H.*, Martial, C.* (contributed equally), Charland-Verville, V., Pallavicini, C., Sanz, C., Zamberlan, F., … Tagliazucchi, E. (2019). Neurochemical models of near- death experiences: A large-scale study based on the semantic similarity of written reports. Consciousness and Cognition, 69, 52–69. Cassol, H., Pétré, B., Degrange, S., Martial, C., Charland-Verville, V., Lallier, F., Bragard, I., Guillaume, M.*, & Laureys, S* (contributed equally). (2018). Qualitative thematic analysis of the phenomenology of near-death experiences. PLOS ONE, 13(2), 1-14. Book chapter: Cassol, H., Martial, M., Charland-Verville, V., & Laureys, S. (in press). Les expériences de mort imminente. In A. Dechêne & B. Dupont (Eds.), Crises (MethIs). Presses Universitaires de Liège. vii Other publications related to near-death experiences: Articles: Martial, C., Cassol, H., Laureys, S., & Gosseries, O. (under review). Near-death experience as a probe to explore (disconnected) consciousness. Martial, C., Mensen, A., Charland-Verville, V., Bahri, M. A., Vanhaudenhuyse, A. Rentmeister, D., Cassol, H., Englebert, J., Laureys, S., & Faymonville, M.-E. (2019). Neurophenomenology of near-death experience memory in hypnotic recall: a within-subject EEG study. Scientific Reports, 9,