Scientific Reports
June 10, 2024
Jussi Jylkkä, Andreas Krabbe, Patrick Jern
11 citations
A cross-sectional internet survey of 701 people who had used classical psychedelics probed their metaphysical beliefs with a new 42-item questionnaire. Factor analysis revealed two main belief clusters: Idealism and Materialism. Idealism was linked to psychological insight from a past psychedelic experience and to average psychedelic use, and it predicted wellbeing. Mediation analyses showed an indirect path from past psychedelic use through Idealism to wellbeing, but not through non-physicalist beliefs generally or through Materialism. The findings suggest that Idealism specifically, rather than non-physicalist beliefs broadly, may mediate the association between psychedelic use and wellbeing, though causality remains unestablished.
Philosophical Psychology
August 14, 2024
Jussi Jylkkä
8 citations
Psychedelics can lead people to adopt mystical-type beliefs, such as the idea that reality is fundamentally loving consciousness, which may improve well-being. Critics argue such beliefs are delusional because they contradict naturalism. This paper argues that naturalism is just one metaphysical position among several internally consistent and scientifically compatible options, making it impossible to definitively choose one. This calls for metaphysical agnosticism, meaning psychedelic-facilitated metaphysical beliefs cannot be dismissed as delusional solely for contradicting naturalism. However, metaphysical agnosticism does not apply to other mystical-type beliefs like paranormal claims, which can be problematic. The author applies this framework to empirical research on psychedelic belief changes, noting that mystical-type beliefs may be ineffable and non-conceptual, so their conceptualizations should not be taken too seriously. Implications for psychedelic-assisted therapy are discussed.
bioRxiv Preprint Server
June 4, 2019
Jussi Jylkkä, Henry Railo
2 citations
preprint
The typical empirical approach to studying consciousness holds that we can only observe the neural correlates of experiences, not the experiences themselves. This paper argues, in contrast, that experiences are concrete physical phenomena that can causally interact with other phenomena, including observers, and therefore can be observed and scientifically modelled. The epistemic gap between an experience and a scientific model of its neural mechanisms stems from the fact that the model is a theoretical construct distinct from the concrete phenomenon it models, similar to any natural phenomenon and its model. A neuroscientific theory of the constitutive mechanisms of an experience is thus a model of the subjective experience itself, providing a solid basis for the empirical study of consciousness.
Konsta Kallio-Mannila, Rosa Salmela, Jussi Jylkkä
2 citations
preprint
Reports of personally meaningful experiences from psychedelic substances and meditation are highly similar in semantic and lexical content, with both groups expressing positive emotions on average. However, psychedelic experience reports are more emotionally charged, showing higher levels of both positive and negative sentiments compared to the more neutral meditation experiences. This suggests emotional intensity may be a distinguishing factor between the two types of experiences. The study used Natural Language Processing methods to analyze open-ended narratives from 197 participants, but challenges with the methods and dataset limit the conclusions that can be drawn.
Psychopharmacology
August 11, 2025
Jussi Jylkkä, Aila Mustamo
1 citation
Most psychedelic researchers (85%) have personal experience with classic psychedelics. They view such experience as beneficial for research but also recognize it as a potential source of bias. Researchers acknowledge the importance of self-reflection and disclosing personal experiences, yet find disclosure challenging in practice. Personal use predicts more positive opinions about psychedelics' potential to improve well-being, transform society, address the ecological crisis, and answer spiritual questions. The findings highlight the prevalence of personal experiences among this sample and their influence on research interests and opinions, underscoring the need for open discussion and reflection.
June 6, 2025
Jussi Jylkkä
1 citation
preprint
Personally meaningful insights from psychedelic experiences and meditation are highly similar, with only minor differences. Analyzing narrative reports from 147 psychedelic users and 66 meditators, three main insight themes emerged: mystical-type (unity, metaphysical, other), psychological (metacognitive, value, compassion), and philosophical-existential (purpose, value, other). Mystical-type insights were more frequent in meditation reports, while value insights were more common in psychedelic reports. Metacognitive and value insights were positively associated with perceived improvements in positive affect, while mystical-type insights predicted increased meaning in life. The findings suggest that transformative experiences are not exclusive to classic psychedelics but can be facilitated through various means, and that existing questionnaires do not fully capture the range of insights reported.
Consciousness and Cognition
December 15, 2025
Andreas Krabbe, Pilleriin Sikka, Jussi Jylkkä
Meditation practice may enhance the benefits of psychedelic experiences and can confound associations between psychedelic use and well-being. In two cross-sectional online surveys, when examined separately, both cumulative psychedelic use and meditation practice were associated with greater well-being and psychological flexibility. However, when considered jointly, the associations for psychedelics were reduced or became nonsignificant, while meditation remained consistently associated with outcomes. In a second study, participants who experienced a personally meaningful event through meditation alone or combined with psychedelics reported significantly greater improvements in well-being compared with those who used psychedelics alone, though all groups showed positive change on average. Weak evidence suggested a potential synergy between the two practices.
October 10, 2023
Jussi Jylkkä
preprint
Psychedelic substances can induce mystical-type experiences that often lead to metaphysical beliefs about the fundamental nature of reality, which have been criticized as incompatible with naturalism and therefore false. This creates two problems: an easy problem of defining what the "fundamental nature of reality" means and whether mystical conceptions of it are compatible with naturalism, and a hard problem of showing how mystical insights, which from a naturalistic perspective are brain processes, could provide insight into reality beyond the brain. The author argues that naturalism is less restrictive than commonly assumed, allowing that reality can be more than what science conveys.