5-MeO-DMT is a short-acting psychedelic that is anecdotally reported to induce a radical disruption of the self and a paradoxical quality of aroused, waking awareness that is nevertheless devoid of any specific perceptual contents. Here, we conducted an exploratory observational study of the phenomenological and neuronal effects of this compound. We collected micro-phenomenological interviews, psychometric questionnaires, and electroencephalography (EEG) in naturalistic ceremonial settings where 5-MeO-DMT was ingested. Results revealed that the 5-MeO-DMT experience followed a dynamic progression that-only in the most extreme cases-manifested as a complete absence of self-experience and other phenomenal content with preserved awareness. Furthermore, visual imagery, bodily self-disruption, narrative self-disruption, and reduced phenomenal distinctions occurred in a variable fashion. EEG analyses revealed the 5-MeO-DMT experience was characterised by (global) alpha and (posterior) beta power reductions, implying a mode of brain functioning where top-down models are inhibited. Our preliminary phenomenological findings confirm the potential utility of 5-MeO-DMT as a pharmacological model for deconstructed consciousness while noting the limitations of employing retrospective questionnaires for this purpose. Considering the exploratory nature of this study and its limitations inherent to its naturalistic nature, further research employing real-time experience sampling and phenomenologically trained participants in controlled environments could expand our findings to meaningfully inform the potential of this tool for the scientific study of consciousness.

3rd Faculty of Medicine Charles University Prague Prague 100 00 Czech Republic

Department of Experimental Psychology University College London London WC1H 0AP UK

Department of Media School of the Arts and Creative Industries University of East London London E16 2RD UK

Department of Neurology University of California San Francisco San Francisco 94143 USA

Department of Neuropsychology and Psychopharmacology Faculty of Psychology and Neuroscience Maastricht University 6229 the Netherlands

Department of Psychiatry and Forensic Medicine Universitat Autònoma de Barcelona Barcelona 08193 Spain

DMT Research Group Centre for Psychedelic Research Department of Brain Sciences Imperial College London London W12 0NN UK

Florey Department of Neuroscience and Mental Health The University of Melbourne Parkville Victoria 3052 Australia

Forensic Laboratory of Biologically Active Substances Department of Chemistry of Natural Compounds University of Chemistry and Technology Prague 166 28 Czech Republic

Fundació Sant Joan de Déu Barcelona 08014 Spain

Medical Anthropology Research Center Universitat Rovira i Virgili Tarragona 43005 Spain

Parc Sanitari Sant Joan de Dèu Barcelona 08830 Spain

Psychedelic Research Center National Institute of Mental Health Klecany 250 67 Czech Republic

Somnivore Pty Ltd Melbourne Victoria 3340 Australia

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