Translated from our German original by AI. The German text was researched, written, and edited by the Psychedelia Foundation team and remains the authoritative version.
A new study in Nature shows that psilocybin does not simply put brain activity into a disordered state. Rather, the substance changes the dynamics of neural networks so that they align more closely with the context being experienced at the time. The results offer new signals about how psychedelic experiences could relate to changes in the experience of self and world.
For the study, researchers examined 62 adults with no prior psychedelic experience. Participants received a standardized dose of 19 milligrams of psilocybin and were examined using functional magnetic resonance imaging (fMRI) and EEG. Measurements took place both without psilocybin and during the acute effect. Various natural situations were compared: rest, meditation, music, and watching a film.
Conventional analysis of time-averaged brain activity initially confirmed known effects of psychedelic substances. Under psilocybin, functional network segregation decreased. Global functional connectivity changed at the same time: while integration decreased in sensory brain regions, particularly with the eyes closed, it increased in associative regions.
Things became more interesting in the analysis of temporal dynamics. Using machine learning methods, the researchers mapped each participant’s brain activity as low-dimensional trajectories. This allowed them to detect a context-dependent organization that remained hidden in the conventional time-averaged analyzes.
Under psilocybin, the patterns of brain activity increasingly differed according to whether participants were at rest, meditating, listening to music, or watching a film. The more strongly participants reported a positively experienced dissolution of the sense of self and of the boundary between self and environment, the more pronounced this context alignment of brain dynamics was.
The researchers describe the associated subjective state as “embeddedness”. What is meant is an experience in which one perceives oneself as less separate from the environment and more continuously connected with it.
This yields a more nuanced picture of the frequently described psychedelic “desynchronization” of the brain. At the level of time-averaged network organization, the usual separation between different networks does indeed decrease. At the same time, the temporal dynamics of brain activity can show a structured and context-dependent order. The apparent disorganization is therefore not to be equated with complete neural randomness.
It is also notable that the strength of this context alignment was related not only to the intensity of self and boundary dissolution. It also correlated with a change in subjective mindset on the following day. The study thus shows a connection between altered brain dynamics, the quality of the psychedelic experience, and subsequent psychological changes. It does not, however, provide causal evidence that the observed brain dynamics cause the later changes.
The results could help explain why the context of a psychedelic experience plays such an important role. They show that psilocybin does not merely lead brain activity away from its normal organization, but can at the same time couple it more flexibly to the situation being experienced.
The study thus adds another signal that the psychedelic state should be understood as something other than mere “disorganization” of the brain. Psilocybin appears instead to fundamentally change the balance between network separation, integration, and temporal context sensitivity.
