Imperial College London


Faculty of MedicineDepartment of Brain Sciences

Honorary Senior Lecturer







Commonwealth BuildingHammersmith Campus





I WAS AT IMPERIAL BETWEEN 2013-2023. It was a fun time, and now I am also having fun time at the University of Exeter

Leor Roseman, PhD, was a Research Fellow at the Centre for Psychedelic Research, Faculty of Medicine, Imperial College London. Leor received his MRes and PhD at Imperial, under the mentorship of Prof. Robin Carhart-Harris and Prof. David Nutt, and with the support of the Imperial College President's Scholarship.

With an interdisciplinary approach, Leor's research encompasses neuroscience, psychology, phenomenology, anthropology and conflict resolution; using a wide array of research methods (fMRI, quantitative, qualitative, microphenomenology, ethnographic, and participatory research)

He has conducted groundbreaking research into

  • the neural correlates of the psychedelic state
  • the role of the visual cortex in psychedelic imagery
  • the therapeutic potential of the psychedelic experience
  • the communal use of psychedelics, and their potential use for peacebuilding.

Leor believes that the social and communal aspects of psychedelic practices are crucial for their therapeutic potential and societal change, and much of his current research is dedicated towards this inquiry.  

Some notable publications (for more publications, see publications tab):

  • Roseman, L., Leech, R., Feilding, A., Nutt, D. J., & Carhart-Harris, R. L. (2014). The effects of psilocybin and MDMA on between-network resting state functional connectivity in healthy volunteers. Frontiers in Human Neuroscience.
    This is the first paper to show increased between-network functional connectivity – a result which has been replicated many times since then.
  • Carhart-Harris, R. L., Muthukumaraswamy, S., Roseman, L., Kaelen, M., Droog, W., Murphy, K., ... & Nutt, D.J. (2016). Neural correlates of the LSD experience revealed by multimodal neuroimaging. PNAS.
  • Roseman, L., Nutt, D. J., & Carhart-Harris, R. L. (2017). Quality of acute psychedelic experience predicts therapeutic efficacy of psilocybin for treatment-resistant depression. Frontiers in Pharmacology.
  • Roseman,L., Demetriou, L., Wall, M. B., Nutt, D. J., & Carhart-Harris, R. L. (2017). Increased amygdala responses to emotional faces after psilocybin for treatment-resistant depression. Neuropharmacology.
  • Carhart-Harris, R. L., Roseman, L., Haijen, E., Erritzoe, D., Branchi, I., & Kaelen, M. (2018). Psychedelics and the essential importance of context. Journal of Psychopharmacology.
  • Roseman, L., Haijen, E., Idialu-Ikato, K., Kaelen, M., Watts, R., & Carhart-Harris, R. (2019). Emotional breakthrough and psychedelics: Validation of the Emotional Breakthrough Inventory. Journal of Psychopharmacology.
  • Kettner, H., Rosas, F. E., Timmermann, C., Kärtner, L., Carhart-Harris, R. L., & Roseman, L. (2021). Psychedelic Communitas: intersubjective experience during psychedelic group sessions predicts enduring changes in psychological wellbeing and social connectedness. Frontiers in Pharmacology.
  • Roseman, L., Ron, Y., Saca, A., Ginsberg, N., Luan, L., Karkabi, N., Doblin, R., & Carhart-Harris, R. (2021). Relational processes in ayahuasca groups of Palestinians and Israelis. Frontiers in Pharmacology.
  • Roseman, L., & Karkabi, N. (2021). On Revelations and Revolutions: drinking Ayahuasca among Palestinians under Israeli occupation. Frontiers in Psychology.
  • Roseman, L., Preller, K., Fotiou, E., & Winkelman, M. (2022). Editorial: Psychedelic Sociality: Pharmacological and Extrapharmacological Perspectives. Frontiers in Pharmacology
  • Watts, R., Kettner, H., Geerts, D., Gandy, S., Kartner, L., Mertens, L., Timmermann, C., Nour, M., Kaelen, M., Nutt, D., Carhart-Harris, R. & Roseman, L. (2022). The Watts Connectedness Scale: a new scale for measuring a sense of connectedness to self, others, and world. Psychopharmacology
  • Aqil, M., & Roseman, L. (2022). More than meets the eye: The role of sensory dimensions in psychedelic brain dynamics, experience, and therapeutics. Neuropharmacology.
  • Timmermann, C., Roseman, L., Haridas, S., Rosas, F., Luan, L., Kettner, H… & Carhart-Harris, R. (2023). Human Brain Effects of DMT determined via fMRI-EEG. PNAS

The brain on LSD revealed: first scans show how the drug affects the brain  | Imperial News | Imperial College London


Keynote talk from Psychedelic Science 2023, MAPS, Denver. 23rd of June 2023 By Sami Awad and Leor Roseman "From personal to collective: ayahuasca as a peace-making tool among Palestinians and Israelis" In the spring of 2022, three groups of Palestinians and Israelis were invited to participate in an ayahuasca peacebuilding program. The invitation was to explore the ceremonial and healing space of ayahuasca through a collective intention: to ground the transformative spiritual practice in the political reality of conflict and oppression; to heal collective trauma and liberate from rigid narratives and ethos; to invite revelations and transform them into actions of co-resistance; to create a community of solidarity and care; and to celebrate life and good music together. In this joint presentation, Sami Awad, a Palestinian peace activist and one of the leading facilitators, will present the program – tailored for this intention - and discuss the processes the groups went through. Leor Roseman, an Israeli psychedelic researcher from the University of Exeter (previously Imperial College London), will present quantitative, qualitative, and phenomenological research findings from the program. The presentation will reveal how psychedelics can be used intentionally for socio-political endeavours beyond personal healing.

Messianic Mystics: When Spirituality and Politics Meet. Breaking Convention 2023 This provocative talk will explore the messianic/prophetic function within psychedelic phenomenology, practices, and movements. In contrast to the archetypal mystical-unitive ahistorical ego-dissolving state, we can find the revelatory-prophetic-messianic state. Such revelatory states are active, sociopolitical, historical, moral, and sometimes full of ego. The talk will examine the messianic events of Allen Ginsberg, Master Irineu, and John Wilson (Moonhead) – which have contributed to the diffusion of LSD, Daime, and Peyote, respectively. Such diffusion of the substances occurs in non-linear bursts, stemming from revelatory events to significant movement. Yet, other micro messianic states and movements occur as well. It will be argued that a weak messianic force exists in many psychedelic practices; that it fills the practice with a sense of mission, meaning, and hope; that revelatory insights are intertwined with redemptive actions; and that the molecules are playing with this messianic function so we will spread them passionately.

"On Revelations and Revolutions in Ayahuasca Rituals of Palestinians and Israelis" from Breaking Convention 2021 (the intermission)
"Psychedelic Sociality" from "Symposium on Psychedelic Science" by Oxford Psychedelic Society. Psychedelics have a long history of bringing people together, facilitating intense shared experiences, and revitalizing cultures. This social dimension of the use of psychedelics—psychedelic sociality—should be considered in the current mainstreaming, as therein lies their potential to support change in individual therapy and beyond. The talk presents evidence regarding the social and relational components of psychedelic use and presents a biopsychosocial perspective on psychedelics' mechanism of action.
"Palestinians, Israelis, and Ayahuasca: Can Psychedelics Promote Reconciliation?" from Breaking Convention 2019
Psychedelic Science Conference 2017 (MAPS) Psilocybin-Assisted Therapy, Neural Changes & the Relationship Between Acute Experiecne and Clinical Outcomes
ICPR 2016 Neural correlates of LSD-induced, eyes-closed, psychedelic Imagery

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Wall MB, Lam C, Ertl N, et al., 2023, Increased low-frequency brain responses to music after psilocybin therapy for depression, Journal of Affective Disorders, Vol:333, ISSN:0165-0327, Pages:321-330

Delli Pizzi S, Chiacchiaretta P, Sestieri C, et al., 2023, Spatial Correspondence of LSD-Induced Variations on Brain Functioning at Rest With Serotonin Receptor Expression, Biological Psychiatry-cognitive Neuroscience and Neuroimaging, Vol:8, ISSN:2451-9022, Pages:768-776

Luppi AI, Hansen JY, Adapa R, et al., 2023, In vivo mapping of pharmacologically induced functional reorganization onto the human brain's neurotransmitter landscape, Science Advances, Vol:9, ISSN:2375-2548

Zafar R, 2023, Psychedelic therapy in the treatment of addiction: the past, present and future, Frontiers in Psychiatry, Vol:14, ISSN:1664-0640, Pages:1-24

Singleton SP, Timmermann C, Luppi AI, et al., 2023, Time-resolved network control analysis links reduced control energy under DMT with the serotonin 2a receptor, signal diversity, and subjective experience., Biorxiv

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