At Monash University in Melbourne, sixty-two adults who had never taken a psychedelic spent part of a day inside a brain scanner, watching a silent video of clouds. Before the clouds came a stretch of rest: a guided meditation, and a long passage of music, all with eyes closed. One participant later described melding with the machine, the floor, the walls, and the air. Half the group ranked the experience among the most meaningful of their lives.
The scans were designed to test a description that had hardened into consensus. For more than a decade the standard account of the psychedelic brain has been desynchronization: entropy, noise, a temporary loss of order. Devon Stoliker, Adeel Razi, and their colleagues, publishing in Nature in August 2026, found order underneath the noise. Brain activity organized itself around whatever each person was doing and perceiving, and the tighter that organization, the deeper the reported loss of the boundary between self and surroundings.
Under psilocybin, the brain’s ordinary separation between inward and outward processing relaxes, and activity reorganizes around what is actually present. The surroundings stop functioning as a backdrop and become part of the event. On this evidence, setting helps determine what a psychedelic experience is.
What the Scanner Found
The design was unusually thorough. Sixty-two people with no prior psychedelic experience were scanned twice, once without a drug and once after a single 19 mg dose of psilocybin, using both fMRI and EEG across four conditions: rest, guided meditation, music, and a silent film of moving clouds.
The analysis is where it gets interesting. Rather than averaging connectivity across a whole scan, the team used machine learning to render each person’s brain activity as a trajectory, a moving line through a compressed space. Averaged over time, the data looked like disorder, which is what previous studies had reported. Followed moment to moment, it showed structure. Each condition produced its own cohesive pattern, and the patterns grew tighter and more distinct in the people reporting the strongest effects. The alignment was strongest in those describing a positively felt dissolution of self and boundary, and it was weak or absent in states dominated by anxiety or confusion.
Two systems carried most of this. The default mode network and the visual network sit at opposite ends of the brain’s principal axis, which runs from internally directed to externally directed processing. Ordinarily these systems are held apart, and the authors note that this separation is what buffers the brain from direct coupling with its environment. Under psilocybin the separation relaxed. Activity recorded with eyes closed came to resemble activity recorded with eyes open.
The authors name the accompanying experience embeddedness, and they distinguish it carefully from connectedness. Connectedness implies links between things that remain separate. Embeddedness is the felt sense of being continuous with one’s surroundings. Its strength tracked how much participants’ mindsets had shifted the following day, measured across connection to self, others, and nature. A month later the group showed higher personal meaning and acceptance of death, along with a smaller rise in relatedness to nature.
The study was open-label with no placebo arm, the four conditions always ran in the same order, and the participants were healthy volunteers. Several associations with individual experience measures were reported without correction for multiple comparisons, and the one-month changes had no comparison group. Context here meant a scanner, a playlist, and a video of clouds. Even within those limits, the finding changes what setting can mean.
Psychedelics & Setting Reconsidered
Set and setting has been repeated as folk wisdom since Timothy Leary coined the term in the 1960s. It’s since been written into clinical guidelines, but has largely been treated as risk management, a matter of comfortable furniture and a reassuring guide. What the Monash data suggest—and the Psygaia hypothesis predicts—is a mechanism. If brain activity organizes itself around present conditions in proportion to the depth of the experience, then the room, the music, the land outside the window, and the people in it are all inside the experience, participating in what it becomes.
Other findings point the same way. Christopher Timmermann’s team at Imperial College London, studying how psychedelic use shifts beliefs about consciousness and reality, found the changes were mediated by how emotionally in sync people felt with others during the experience, and moderated by how impressionable they were beforehand. What lasts depends on who and what is present.
This is the enactive, or ecological account of mind arriving from a new direction.
Francisco Varela, Evan Thompson, and Eleanor Rosch argued that cognition is something an organism performs together with its environment, and that perception brings forth a world rather than receiving one. The Psygaia hypothesis begins from the same premise: cognition is always ecological because it arises through organism-environment relations. Psychedelics do not make cognition ecological; they alter that relation, loosening some of the constraints that ordinarily stabilize perception and selfhood, allowing the immediate environment to exert more influence over what is felt, noticed, understood, and made meaningful. The meaning that emerges belongs neither to the molecule nor the brain alone, but to the relation among organism, substance, and setting.
One possible outcome is what the Psygaia hypothesis calls ecological attunement: interdependence within living systems becoming felt and relevant to how a person perceives and acts. Psychedelics do not produce it automatically. It depends on what the altered organism is coupled to.
A scanner and a playlist are a very narrow slice of environment, and so is a traditional therapy room. The study did not look at forests or ceremonies, but it gives us reason to think the same process may be at work there. We now have a plausible account of why the natural settings people so often and intuitively seek out may matter: they do not merely surround the experience; they help constitute it.
If setting participates in what the experience becomes, the question is no longer only whether a setting is safe. It is what kind of world that setting helps bring forth.
The Traditions Were Exact About Context
Among the mestizo vegetalistas of the Iquitos region in the Peruvian Amazon, certain plants are called doctores, or vegetales que enseñan, the plants that teach. Luis Eduardo Luna, the anthropologist and Psygaia advisor, introduced the concept to Western scholarship in a 1984 paper, rendering the phrase in English as plant teachers, and developed it at book length in Vegetalismo two years later.
The phrase makes a claim about instruction. The practice around it makes a claim about conditions. The practitioners Luna worked with undertook prescribed diets for two to three years, largely in isolation, while cultivating relationships with particular species. Whatever one concludes about the spirits of plants, the method encodes a precise understanding of context, maintained far beyond the hours or days a compound is active. The dieta is a long argument about what surrounds a person—the environment the organism couples with.
It also complicates the assumption that the active substance is the medicine. Plant teachers are not limited to species that Western pharmacology classifies as psychedelic. What makes them teachers is the relationship cultivated through diet, solitude, dreams, bodily discipline, and attention, often with ayahuasca serving as only one part of the practice. The lesson is not extracted from a chemical and delivered to a brain. It takes shape through an extended encounter among a person, a plant, a place, and an inherited practice.
This is where the Psygaia hypothesis meets vegetalismo most clearly—not by claiming that neuroscience has explained plant spirits, but by taking seriously the possibility that cognition and healing emerge through relations that exceed the individual. A conventional pharmacological model asks what a drug does to a patient. The ecological question is what becomes possible within a particular relation among organism, medicine, and world.
Read this way, the dieta is not simply an unusually elaborate set and setting. It is a method for changing the organism-environment relation itself. The Monash study examines that relation over minutes, while vegetalismo cultivates it over months or years. They are not making the same claim, but they converge on one point: context is not packaging around the experience. It is one of the processes through which the experience—and perhaps the teaching—takes form.
If context helps shape the experience, the next question is what it leaves behind.
What Settles Afterward
Stoliker and colleagues add an observation with consequences beyond the session.
Because the reorganization depended on what each person was doing and perceiving, they suggest the synaptic changes that follow may themselves be shaped by that ongoing activity. Plasticity does not stop when the acute effects do.
That turns the weeks after a session into part of the event. What a person repeatedly attends to during that window helps determine which patterns consolidate, which is why integration practices that consist of a single debrief and a return to ordinary life tend to produce little transformation. My emerging practical framework—based on the Psygaia Hypothesis—calls this an ethics of attention, and it changes the guiding question from what an experience meant to one person to what it asks of them within the relationships they are part of. Our past essay on psychedelics as lifelong relational practice follows that question across the span of a life.
The same principle also raises the stakes on a question the field mostly leaves to chance. If a brain in this state aligns with its context, then whatever context a culture supplies becomes the default. A clinical suite and a return to the office the next Monday are settings too.
The paper closes with a line that reverses the usual story. The felt boundary between self and world, the authors argue, is actively maintained by neural activity, and the continuity that appears when that maintenance relaxes may chiefly reveal what ordinary brain dynamics keep apart.
The paper closes by reversing the usual story. The boundary between self and world, the authors argue, is something the brain actively maintains. When that activity relaxes, continuity appears.
Ancient nondual traditions have long said: I am That. Perhaps psychedelics do not create that unity. They interrupt the brain’s work of keeping self and world apart.
Separation was the achievement all along.
Sources
Belleau, L. (2026). The Psygaia Hypothesis: Psychedelic Experience & Ecological Cognition.
Belleau, L. (2025). The Psygaia Framework: Psychedelic Integration as Ecological Reconnection.
Luna, L. E. (1984). The concept of plants as teachers among four mestizo shamans of Iquitos, northeastern Peru. Journal of Ethnopharmacology, 11, 135–156.
Luna, L. E. (1986). Vegetalismo: Shamanism among the mestizo population of the Peruvian Amazon. Almqvist & Wiksell International.
Stoliker, D., Novelli, L., Khajehnejad, M., Biabani, M., Greaves, M. D., Barta, T., Williams, M., Chopra, S., Bazin, O., Simonsson, O., Chambers, R., Barrett, F. S., Deco, G., Preller, K. H., Carhart-Harris, R. L., Seth, A. K., Sundram, S., Egan, G. F., & Razi, A. (2026). Psychedelics align brain activity with context. Nature, 656(8129), 936–947. https://doi.org/10.1038/s41586-026-10910-z
Timmermann, C., Kettner, H., Letheby, C., Roseman, L., Rosas, F. E., & Carhart-Harris, R. L. (2021). Psychedelics alter metaphysical beliefs. Scientific Reports, 11, Article 22166. https://doi.org/10.1038/s41598-021-01209-2
Varela, F. J., Thompson, E., & Rosch, E. (1991). The embodied mind: Cognitive science and human experience. MIT Press.
