Exploring the Neural State of “Embeddedness” Under Psilocybin
Article Title: “Functional embeddings of human brain states reveal “embeddedness” of the self in the psychedelic state”
Author: Razi, A., Perl, Y. S., Mediano, P. A. M., Rosas, F. E., Kettner, H., Lodder, P., Timmermann, C., & Carhart-Harris, R.
Publication Date: 2025
Background
Psychedelics like psilocybin are known for inducing profound alterations in consciousness, often described as ego dissolution or unity with the environment. However, the brain mechanisms that underpin such experiences remain unclear. This study sought to illuminate these mechanisms by examining how psilocybin changes functional brain organisation—particularly how the self relates to its environment—and introducing the novel concept of “embeddedness.”
Study Overview
The researchers recruited 65 healthy, psychedelic-naïve adults and administered a moderate dose of psilocybin. Brain activity was recorded using fMRI across four conditions: resting, listening to music, watching a movie, and guided meditation. Participants also completed a range of psychometric assessments, including the Mystical Experience Questionnaire (MEQ30) and the 11-Dimensional Altered States of Consciousness (11D-ASC).
Advanced machine learning techniques—Contrastive Embedding for Behavioural and Neural Analysis (CEBRA) and Temporal Attention-Variational Graph RNN (TAVRNN)—were used to analyse fMRI data, generating “functional embeddings” that captured patterns of brain connectivity.
Key Findings
Embeddedness Defined: Under psilocybin, participants exhibited a novel brain state characterised by increased integration across brain networks and decreased distinction between internal and external experiences. This state was termed “embeddedness.”
Functional Trajectories Shifted: CEBRA revealed distinct and consistent brain state clusters under psilocybin, corresponding to environmental and psychological contexts, unlike baseline conditions.
Enhanced Network Integration: TAVRNN analyses showed more fluid and flexible interactions between different brain regions under psilocybin, particularly across the default mode, salience, and attention networks.
Subjective Alignment: Classification accuracy of brain state trajectories strongly correlated with mystical-type experiences, especially unity and blissful states (r > 0.5).
Discussion
This study provides compelling evidence that psilocybin induces a functional reorganisation of the brain, leading to a state of increased neural integration. The concept of “embeddedness” captures how the self becomes more integrated within environmental and cognitive contexts—a state reflected both in brain dynamics and in subjective reports of ego dissolution, unity, and transcendence.
The use of advanced ML models allowed researchers to extract low-dimensional representations of complex brain states, offering a clearer picture of how consciousness changes under psychedelics. Interestingly, while reduced within-network connectivity is often interpreted as disintegration, this study shows it may actually signal a shift to a more flexible, adaptive state.
Implications
The findings offer a new framework for understanding the psychedelic experience—not as a chaotic breakdown of brain activity, but as a coherent, integrated state with unique neurobiological properties. This could enhance how retreats and therapeutic settings conceptualise and facilitate ego-transcendent experiences.
It also provides a potential biomarker for identifying and tracking altered states, with possible implications for depression, PTSD, and addiction treatment, where rigid patterns of self-referential thinking are common.
Potential Application
For psychedelic retreats, these insights validate practices that cultivate openness, presence, and surrender. Facilitated environments that include music, nature, and meditation might further support the emergence of “embeddedness,” maximising the therapeutic potential of psilocybin experiences.
Future work may help identify individual readiness for psychedelic therapy by examining baseline brain states and the likelihood of reaching these integrated neural configurations.
Conclusions
This study breaks new ground in psychedelic neuroscience by identifying “embeddedness” as a central feature of the psilocybin experience. By showing how brain connectivity becomes more integrated and contextually responsive, the research deepens our understanding of how psychedelics shift consciousness and provides a framework for guiding safe and effective therapeutic use.
Reference:
Razi, A., Perl, Y. S., Mediano, P. A. M., Rosas, F. E., Kettner, H., Lodder, P., Timmermann, C., & Carhart-Harris, R. (2025). Functional embeddings of human brain states reveal “embeddedness” of the self in the psychedelic state. bioRxiv. https://doi.org/10.1101/2025.03.09.642197
