When somebody takes a psychedelic and they’re able to close their eyes and see complex imagery, there seems to be less boundary between the internal and external world than we ordinarily experience.
Stoliker
Half of the participants in a recent study ranked their psychedelic session among the most meaningful experiences of their lives, with 24 individuals placing it in their personal top five.
Researchers analyzing brain scan data from participants under psilocybin found that sensory regions lost influence while associative regions gained dominance.
Brain Networks Reorganize Under Psilocybin
To investigate the phenomenon, the research team measured global functional connectivity, evaluating how much influence each patch of the cortex exerts over the rest of the brain. When participants had their eyes closed during the sessions, sensory regions lost sway while associative regions gained influence.
It seems like the brain’s ability to construct reality, or imagination, or our associations, our beliefs, our sense of self—these faculties had more dominance over sensory areas.
Stoliker
Stoliker stressed that this interpretation remains a hypothetical one.
This could help explain why people have meaningful, complex imagery experiences, why they have mystical experiences with imagery that is personally relevant to them,
he noted.
Network Modularity Drops Across Brain Regions
The team also observed that connections within individual brain networks weakened, while connections between different networks strengthened. The brain's modularity—a parameter describing how cleanly neurons stay sorted into specialist teams—dropped across all four parts of the experimental sequence.
Visual Activity Parity Shrinks Under Psilocybin
When sober, activity in a brain with its eyes shut typically looks very different from a brain watching a movie. Under psilocybin, however, that difference nearly evaporated. In the visual network, the gap between eyes-open and eyes-closed connectivity shrank by 85 percent.
Independent confirmation came from EEG sessions, which showed alpha-band activity—normally a marker of the brain gating visual input—reduced by nearly half.
Data Analysis Reveals Hidden Order
While these details reproduced the underlying chaos that many researchers previously attributed to psychedelics, the team discovered that processing the data through an unorthodox approach revealed a hidden order beneath the surface activity.
