# PRSM Lab

> We study psychedelic, religious, self-transcendent and mystical experiences at Leiden University. PRSM stands for Psychedelic, Religious, Self-transcendent and Mystical experiences. The lab is part of the Cognitive Psychology Unit, Faculty of Social and Behavioural Sciences, Leiden University (the Netherlands), led by Michiel van Elk. Contact: prsmlab@fsw.leidenuniv.nl

## Research topics
- [Psychedelic](https://prsmlab.com/topics/psychedelics): Psychedelics, such as psilocybin and LSD, are substances that profoundly affect perception and consciousness. At PRSM lab, we aim to unravel the neurocognitive mechanisms underlying the psychedelic experience in humans, using both neuroimaging and…
- [Religious](https://prsmlab.com/topics/religion): People of all times and cultures have endorsed religious beliefs and have had encounters with the supernatural. The PRSM lab investigates how these beliefs and experiences come about.
- [Self-transcendent](https://prsmlab.com/topics/spirituality): Self-transcendent experiences are characterised by strong feelings of connectedness and a loss of self. These experiences can be induced through vast natural beauty, great works of art or contemplative practices.
- [Mystical](https://prsmlab.com/topics/mysticism): Mystical experiences are characterised by feelings of unity, insight and ineffability. A key question in the study of mystical experiences concerns whether these experiences reflect a universal, deeply engrained prototype, or whether they are shaped and…

## Research projects
- [INTEGRATE (MSCA Doctoral Network) — DC10: Methodological challenges in psychedelic research](https://prsmlab.com/projects/integrate-msca-doctoral-network-dc10-methodological-challenges-in-psychedelic-research): The PRSM lab hosts one of sixteen doctoral positions in INTEGRATE, a pan-European Marie Skłodowska-Curie Doctoral Network training the next generation of experts in psychedelic therapy, running from 2026 to 2030 across…
- [Open Psilocybin Project](https://prsmlab.com/projects/open-psilocybin-project): Using open science practices to assess the effects of psilocybin on the brain, the body and self-perception
- [Mystical Entropy](https://prsmlab.com/projects/mystical-entropy): The Mystical Entropy project seeks to develop a new theoretical framework for the scientific study of mystical experiences and spiritual practices.
- [The psychological and neurocognitive effects of awe experiences on self-perception.](https://prsmlab.com/projects/the-psychological-and-neurocognitive-effects-of-awe-experiences-on-self-perception): This project explores the effects of different types of awe experiences (e.g., positive awe, threatening awe) on self-perception and attention (e.g., visual).
- [Altered states brain dynamics database](https://prsmlab.com/projects/altered-states-brain-dynamics-database): In this project, we investigate resting-state fMRI connectivity of different pharmacologically and non-pharmacologically induced altered states of consciousness.
- [Open Science of Religion Project](https://prsmlab.com/projects/open-science-of-religion-project): To foster openness and transparency in the psychology of religion and spirituality (PRS), together with the joint editors of 3 PRS journals, we have launched a Call for Proposals.
- [Scale Development](https://prsmlab.com/projects/scale-development): We are actively involved in developing, revising, and translating several psychometric scales.
- [Psychedelic Retreat Studies](https://prsmlab.com/projects/psychedelic-retreats): We collaborate with several retreat organizations to investigate the effects of psychedelics in naturalistic / ceremonial settings.
- [Microdosing](https://prsmlab.com/projects/microdosing): Microdosing is an increasingly popular trend amongst psychedelic communities and refers to a practice where individuals consume sub-perceptual amounts of a psychedelic substance (e.g., LSD or psilocybin) every 2-4 days.
- [VIDI project ‘Putting Psychedelics in Perspective’](https://prsmlab.com/projects/vidi-project-putting-psychedelics-in-perspective): The NWO-funded VIDI project ‘Putting Psychedelics in Perspective’ (2021-2026) focuses on conducting basic neurocognitive research to better understand the working mechanisms underlying psychedelic substances.

## Studies
- [Many Analysts Psychedelic Project (MAPP)](https://prsmlab.com/studies/many-analysts-psychedelic-project-mapp): Open for participants. Psychedelic experiences are measured with a patchwork of questionnaires — the Mystical Experience Questionnaire, the Challenging Experience Questionnaire, the Ego Dissolution Inventory, the 11-Dimensional Altered States…
- [Open Psilocybin Study (OPS)](https://prsmlab.com/studies/open-psilocybin-study-ops): The Open Psilocybin Study is a randomised, double-blind, placebo-controlled crossover trial investigating how psilocybin changes the brain, the body and self-perception in healthy volunteers.
- [Psychedelic Retreats and the Dynamics of Transformation](https://prsmlab.com/studies/psychedelic-retreats-and-the-dynamics-of-transformation): In collaboration with retreat centers Eremia , Psytide , and Rejuvyn, this study is exploring the dynamics of personal transformation induced by the naturalistic use of psilocybin-containing truffles in retreat settings.
- [The effects of psilocybin on perceptual processing: a 7T fMRI study](https://prsmlab.com/studies/the-effects-of-psilocybin-on-perceptual-processing-a-7t-fmri-study): In this study we investigate the effects of low to moderate doses of psilocybin on perceptual processing in healthy volunteers. The aim of this project is to unravel the basic neurocognitive mechanisms underlying the…
- [Effect of S-Ketamine on Self and Body Perception in Healthy Adults](https://prsmlab.com/studies/ketamine): The aim of this study is to determine how an intravenous infusion of S-ketamine compared to a placebo affects implicit body perception and neural signals to self-related information.
- [Self-experimentation among psychedelic researchers, facilitators and clinicians](https://prsmlab.com/studies/self-experimentation): Open for participants. The aim of this online survey study is to evaluate the prevalence of self-experimentation with psychedelics among psychedelic researchers, clinicians and facilitators.
- [The effects of psychedelic retreats on the brain](https://prsmlab.com/studies/retreat-leiden-university-fmri-study): In collaboration with retreat centers Innerlijke Reis, Inward Bound and Set and Setting , our research team is conducting a study with the purpose of uncovering the underlying brain activity and connectivity changes…
- [The effect of a psilocybin retreat on the narratives of religious leaders](https://prsmlab.com/studies/the-effect-of-a-psilocybin-retreat-on-the-narratives-of-religious-leaders): This study used self-report quantitative and open-ended survey questions as well as a semi-structured interview to investigate the experiences of 12 religious leaders at a psilocybin retreat.
- [Towards a brief Altered States of Consciousness Rating Scale](https://prsmlab.com/studies/towards-a-brief-altered-states-of-consciousness-rating-scale): Open for participants. This study aims to confirm the factor structure of the Altered States of Consciousness scale and to develop a brief alternative based on this structure.
- [Development of the Altered States of Self-Consciousness Scale](https://prsmlab.com/studies/development-of-the-altered-states-of-self-consciousness-scale): This study aims to develop a new scale to assess changes in narrative and embodied self related to altered states of consciousness such as those induced by psychedelics and meditation.
- [Dutch translation of the Psychological Insight Questionnaire and the Emotional Breakthrough Inventory](https://prsmlab.com/studies/dutch-translation-of-the-psychological-insight-questionnaire-and-the-emotional-breakthrough-inventory): The Psychological Insight Scale (Peill et al., 2022) and the Emotional Breakthrough Inventory (Roseman et al., 2019) are psychometric scales that are commonly used in research investigating the effect of psychedelic…
- [The feasability of MDMA-assisted therapy for youth with PTSD](https://prsmlab.com/studies/the-feasability-of-mdma-assisted-therapy-for-youth-with-ptsd): Our research group has performed focus groups with youth with a history of psychiatric care, parents, and clinicians to assess their views on MDMA-assisted therapy for youth with PTSD.
- [Assessing the psychedelic experience](https://prsmlab.com/studies/assessing-the-psychedelic-experience): In this survey study, we investigate how people describe and understand their psychedelic experiences and try to assess to what extent instruments capture these.
- [Exploring Self-Other Processing in the Psychedelic State](https://prsmlab.com/studies/exploring-self-other-processing-in-the-psychedelic-state): This study that aims to investigate the modulation of self-other processing in the psychedelic state. This will be achieved by recording the responses of participants while they perform an online cognitive task two…
- [Effect of Psychedelics on Core Beliefs -Online Survey Study](https://prsmlab.com/studies/effect-of-psychedelics-on-core-beliefs-online-survey-study): We are recruiting people who are planning to attend a psychedelic ceremony and are interested in completing our surveys before and after their experience.

## Publications
- [History repeating: guidelines to address common problems in psychedelic science](https://prsmlab.com/publications/history-repeating-guidelines-to-address-common-problems-in-psychedelic-science): van Elk, M., & Fried, E. I. (2023). History repeating: guidelines to address common problems in psychedelic science. Therapeutic Advances in Psychopharmacology, 13, 20451253231198466.
- [Psilocybin microdosing does not affect emotion-related symptoms and processing: A preregistered field and lab-based study](https://prsmlab.com/publications/psilocybin-microdosing-does-not-affect-emotion-related-symptoms-and-processing-a-preregistered-field-and-lab-based-study): Marschall, J., Fejer, G., Lempe, P., Prochazkova, L., Kuchar, M., Hajkova, K., & van Elk, M. (2022). Psilocybin microdosing does not affect emotion-related symptoms and processing: A preregistered field and lab-based study. Journal of psychopharmacology, 36(1), 97–113. https://doi.org/10.1177/02698811211050556
- [Sixty years of studying the sacred: Auditing and advancing the psychology of religion and spirituality](https://prsmlab.com/publications/sixty-years-of-studying-the-sacred-auditing-and-advancing-the-psychology-of-religion-and-spirituality): Davis, E. B., Lacey, E. K., Heydt, E. J., LaBouff, J. P., Barker, S. B., Van Elk, M., & Ladd, K. L. (2022). Sixty years of studying the sacred: Auditing and advancing the psychology of religion and spirituality. Psychology of Religion and Spirituality.
- [Future Directions for Clinical Psychedelic Research: The Relaxed Symptom Network](https://prsmlab.com/publications/future-directions-for-clinical-psychedelic-research-the-relaxed-symptom-network): Lewis-Healey, E., Laukkonen, R., & van Elk, M. (2022). Future directions for clinical psilocybin research: The relaxed symptom network. Psychology and Neuroscience, 15(3), 223–235.
- [Pharmacological, Neural, and Psychological Mechanisms underlying Psychedelics: A Critical Review](https://prsmlab.com/publications/pharmacological-neural-and-psychological-mechanisms-underlying-psychedelics-a-critical-review): van Elk, M. & Yaden, D.B. (2022). Pharmacological, Neural, and Psychological Mechanisms underlying Psychedelics: A Critical Review. Neuroscience and Biobehavioral Reviews.
- [Ayahuasca and Public Health II: Health Status in a Large Sample of Ayahuasca-Ceremony Participants in the Netherlands](https://prsmlab.com/publications/ayahuasca-and-public-health-ii-health-status-in-a-large-sample-of-ayahuasca-ceremony-participants-in-the-netherlands): Kohek, M., Ona, G., van Elk, M., Dos Santos, R. G., Hallak, J. E., Alcázar-Córcoles, M. Á., & Bouso, J. C. (2022). Ayahuasca and public health II: Health status in a large sample of ayahuasca-ceremony participants in the Netherlands. Journal of Psychoactive Drugs, 1–12.
- [Effects of psilocybin microdosing on awe and aesthetic experiences: a preregistered field and lab-based study](https://prsmlab.com/publications/effects-of-psilocybin-microdosing-on-awe-and-aesthetic-experiences-a-preregistered-field-and-lab-based-study): van Elk, M., Fejer, G., Lempe, P., Prochazckova, L., Kuchar, M., Hajkova, K., & Marschall, J. (2021). Effects of psilocybin microdosing on awe and aesthetic experiences: a preregistered field and lab-based study. Psychopharmacology, 1-16.
- [Working with Weirdness: a response to ‘Moving Past Mysticism in Psychedelic Science’](https://prsmlab.com/publications/working-with-weirdness-a-response-to-moving-past-mysticism-in-psychedelic-science): Breeksema, J. & van Elk, M., (2021). Working with Weirdness: a response to ‘Moving Past Mysticism in Psychedelic Science’. ACS Pharmacology & Translational Science.
- [Religious delight: a non-functional approach to playful religious experiences](https://prsmlab.com/publications/religious-delight-a-non-functional-approach-to-playful-religious-experiences): van Elk, M. (2021). Religious delight: a non-functional approach to playful religious experiences. Religion, Brain & Behavior, 11(2), 224-227.
- [A predictive processing framework of tool use](https://prsmlab.com/publications/a-predictive-processing-framework-of-tool-use): van Elk, M. (2021). A predictive processing framework of tool use. Cortex.
- [Religious Unbelief in Israel: A Replication Study Identifying and Characterizing Unbelievers Using Latent Class Analysis](https://prsmlab.com/publications/religious-unbelief-in-israel-a-replication-study-identifying-and-characterizing-unbelievers-using-latent-class-analysis): van Elk, M. & Naaman, L., (2020). Religious Unbelief in Israel: A Replication Study Identifying and Characterizing Unbelievers Using Latent Class Analysis. International Journal for the Psychology of Religion.
- [Broadening Your Mind to Include Others-The relationship between serotonergic psychedelic experiences and maladaptive narcissism](https://prsmlab.com/publications/broadening-your-mind-to-include-others-the-relationship-between-serotonergic-psychedelic-experiences-and-maladaptive-narcissism): van Mullukom, V., Patterson, R. & van Elk, M. (2020). Broadening Your Mind to Include Others-The relationship between serotonergic psychedelic experiences and maladaptive narcissism. Psychopharmacology
- [Experimentally induced awe does not affect implicit and explicit time perception](https://prsmlab.com/publications/experimentally-induced-awe-does-not-affect-implicit-and-explicit-time-perception): van Elk, M. & Rotteveel, M., (2019). Experimentally induced awe does not affect implicit and explicit time perception. Attention, Perception, & Psychophysics, 1-12.
- [Relationship Between Individual Differences in Gray Matter Volume and Religiosity and Mystical Experiences: A Pre-registered Voxel-based Morphometry Study](https://prsmlab.com/publications/relationship-between-individual-differences-in-gray-matter-volume-and-religiosity-and-mystical-experiences-a-pre-registered-voxel-based-morphometry-study): van Elk, M. & Snoek, L., (2019). The Relationship Between Individual Differences in Gray Matter Volume and Religiosity and Mystical Experiences: A Pre-registered Voxel-based Morphometry Study. European Journal of Neuroscience, 51(3), 850-865.
- [The role of alcohol in expectancy-driven mystical experiences: a pre-registered field study using placebo brain stimulation](https://prsmlab.com/publications/the-role-of-alcohol-in-expectancy-driven-mystical-experiences-a-pre-registered-field-study-using-placebo-brain-stimulation): David L. R. Maij, Michiel van Elk & Uffe Schjoedt (2019) The role of alcohol in expectancy-driven mystical experiences: a pre-registered field study using placebo brain stimulation, Religion, Brain & Behavior, 9:2, 108-125, DOI: 10.1080/2153599X.2017.1403952

## Team
- [Lukas Heinrich](https://prsmlab.com/team/lukas-heinrich): PhD candidate
- [Aidan Lyon](https://prsmlab.com/team/aidan-lyon): Research associate, alumni
- [Ewa Waskian](https://prsmlab.com/team/ewa-waskian): Research master’s student
- [Melissa Vazquez Ruiz](https://prsmlab.com/team/melissa-vazquez-ruiz): Research master’s student, alumni
- [Anna Karl](https://prsmlab.com/team/anna-karl): Research master’s student, alumni
- [Agnese Ferrante](https://prsmlab.com/team/agnese-ferrante): Research master’s student
- [Nino Breunesse](https://prsmlab.com/team/nino-breunesse): Master’s student, alumni
- [Job Flameling](https://prsmlab.com/team/job-flameling): Master’s student, alumni
- [Josjan Zijlmans](https://prsmlab.com/team/josjan-zijlmans): Postdoctoral researcher
- [Chenxiao Zhao](https://prsmlab.com/team/chenxiao-zhao): PhD candidate
- [Xaver Funk](https://prsmlab.com/team/xaver-funk): PhD candidate
- [Julian Heller](https://prsmlab.com/team/julian-heller): PhD candidate
- [Huseyin Beykoylu](https://prsmlab.com/team/huseyin-beykoylu): PhD candidate
- [Josephine Marschall](https://prsmlab.com/team/josephine-marschall): PhD candidate
- [Suzanne Hoogeveen](https://prsmlab.com/team/suzanne-hoogeveen): PhD candidate (graduated 2023), alumni
- [Michiel van Elk](https://prsmlab.com/team/michiel-van-elk): Principal investigator, associate professor

## In the media
- [Trippen voor de wetenschap: Michiel van Elk onderzoekt het effect van psychedelische drugs (en probeert daarom de middelen ook zelf)](https://prsmlab.com/media-mentions/trippen-voor-de-wetenschap-michiel-van-elk-onderzoekt-het-effect-van-psychedelische-drugs-en-probeert-daarom-de-middelen-ook-zelf): Dagblad van het Noorden
- [Public Science Day Psychedelics 2024](https://prsmlab.com/media-mentions/public-science-day-psychedelics-2024): Leiden University. Nooit is er zoveel onderzoek gedaan naar de therapeutische werking van psychedelica als nu. Wetenschappers op de LIBC Publieksdag zijn verheugd over de…
- [Awesome awe: The emotion that gives us superpowers](https://prsmlab.com/media-mentions/newscientist-awesome-awe-the-emotion-that-gives-us-superpowers): New Scientist. Have you ever been stopped in your tracks by a stunning view, or gobsmacked by the vastness of the night sky? Have you been transported by soaring music, a…
- [Fons test microdosing LSD: blijkt voor hem complete onzin](https://prsmlab.com/media-mentions/radar-fons-test-microdosing-lsd-blijkt-voor-hem-complete-onzin): Radar (AVROTROS). Na twee weken krijgt hij de uitslag van onderzoeker Josi Marschall van de Universiteit Leiden. Voordat ze hem deze uitslag geeft wil ze uiteraard weten wat hij…
- [Microdosing psilocybin for anxiety and depression? A placebo may be just as good](https://prsmlab.com/media-mentions/bigthink-microdosing-psilocybin-for-anxiety-and-depression-a-placebo-may-be-just-as-good): Big Think. But does microdosing really work? That was the main question behind a recent placebo-controlled study that explored whether microdosing psilocybin — the main…
- [No difference between psilocybin microdosing and placebo, trial finds](https://prsmlab.com/media-mentions/new-atlas-no-difference-between-psilocybin-microdosing-and-placebo): New Atlas. Corresponding author on the study, Michiel van Elk tells New Atlas his team found no tangible differences in participants comparing the periods they were…
- [More People Are Microdosing for Mental Health. But Does It Work?](https://prsmlab.com/media-mentions/the-new-york-times-more-people-are-microdosing-for-mental-health-but-does-it-work): The New York Times. The two largest placebo-controlled trials of microdosing were published last year, and they both suggest that the benefits people experience are from the…
- [Psilocybin microdosing does not reduce symptoms of depression or anxiety, according to placebo-controlled study](https://prsmlab.com/media-mentions/psypost-psilocybin-microdosing-does-not-reduce-symptoms-of-depression-or-anxiety-according-to-placebo-controlled-study): PsyPost. “The main interest in this topic stems from anecdotal reports of people who microdose and say they experience the beneficial effects. Many people do this in…
- [Interview on putting the psychedelic revival in perspective](https://prsmlab.com/media-mentions/interview-on-putting-the-psychedelic-revival-in-perspective-dutch-radio-1): NPO Radio 1. PRSM was mentioned on Dutch Radio 1! Vorige week is voor het eerst in Europa de psychedelische drug MDMA gebruikt voor een traumabehandeling. Psychedelische…
- [Awe-inspiring psychedelic trips reduce narcissism by boosting connectedness and empathy, study suggests](https://prsmlab.com/media-mentions/psypost-awe-inspiring-psychedelic-trips-reduce-narcissism-by-boosting-connectedness-and-empathy-study-suggests): PsyPost. New research suggests that feelings of awe from psychedelic drugs can positively affect narcissistic personality traits. The study, published in the journal…
- [Fake ‘God Helmet’ can elicit extraordinary experiences — especially among ‘spiritual’ people](https://prsmlab.com/media-mentions/psypost-fake-god-helmet-can-elicit-extraordinary-experiences-especially-among-spiritual-people): PsyPost. Some people report “extraordinary experiences” after wearing a skateboarding helmet with inactive wires attached to it — particularly those who describe…