For roughly a decade, the dominant consensus in neuroscience has held that psychedelic drugs push the human brain into a state of heightened chaos. According to this standard model, the neatly segregated brain networks responsible for processing sensory input, directing attention, and maintaining a stable sense of self begin to break down. Boundaries blur, cross-talk spikes wildly between normally isolated regions, and electroencephalogram (EEG) readings display unprecedented noise and complexity.
"Think of the networks of the brain as highways," explains Devon Stoliker, a neuroscientist at Monash University. "Under psychedelics, these highways break down into many different directions."
Yet, while this "highway breakdown" model neatly describes generalized neural disruption, it has long struggled to explain the profound sense of personal meaning that often accompanies a psychedelic trip. If psilocybin simply scrambled brain signals into random noise, why would users report deeply coherent epiphanies, emotional clarity, and long-lasting psychological healing?
In a study published in Nature, Stoliker and an international team of researchers set out to test whether the neural activity induced by psychedelics is truly random chaos—or whether science simply lacked the right tools to detect its underlying structure. By combining careful experimental design with advanced machine learning, the researchers scanned the brains of dozens of first-time psychedelic users and uncovered a surprising layer of dynamic, highly organized order hidden beneath the apparent disorder.
An Uninterrupted Trip
To Stoliker, the traditional framework framing psychedelics as engines of pure chaos was fundamentally incomplete. "It never really explained why an individual would have a meaningful experience, why they might have insight, why they might experience clarity, and why these might translate into positive psychological changes," Stoliker says.
To resolve this discrepancy, Stoliker and his colleagues launched a study named PsiConnect. The experiment was built around 62 healthy volunteers who had never previously taken a psychedelic substance. Each participant was administered a standardized 19-milligram dose of psilocybin—the primary psychoactive compound found in psilocybin mushrooms—and placed inside neuroimaging scanners to observe their brain activity in real time.
The design of PsiConnect departed significantly from traditional brain-imaging protocols. In conventional neuroscience experiments, participants inside functional Magnetic Resonance Imaging (fMRI) scanners are usually asked to complete specific cognitive tasks, such as pressing buttons in response to visual cues or solving memory puzzles. However, Stoliker’s team intentionally omitted these structured tasks.
"We wanted ecological validity," Stoliker explains. "We wanted to know what the brain was like when somebody was having an authentic, uninterrupted psychedelic experience. If somebody took a psychedelic in a therapeutic setting, you wouldn’t have them completing tasks."
Moreover, previous neuroimaging research suggests that forcing a doused subject to focus on a cognitive task triggers a phenomenon known as "grounding"—effectively pulling the individual out of the psychedelic state and altering the very brain dynamics under observation. "Once you introduce these sorts of tasks, you’re actually interrupting the very phenomena you are seeking to measure," Stoliker notes.
Instead, the team devised a four-part experimental sequence designed to capture naturalistic human experiences without cognitive disruption. Volunteers went through the exact same four-part routine twice: once sober, and once while under the influence of psilocybin. The sequence comprised:
- Eight minutes of resting quietly with eyes closed.
- A period of guided meditation.
- An 11-minute curated musical playlist.
- Six minutes of watching an eyes-open video depicting clouds moving across the sky.
Each volunteer completed this continuous routine inside an fMRI scanner approximately 80 minutes after receiving their dose, capturing peak brain blood-flow dynamics. Later, roughly 150 minutes post-dose, participants underwent EEG recordings while repeating the protocol to track high-speed electrical activity across the scalp.
The naturalistic approach proved highly effective in eliciting authentic psychedelic states. Half of the 62 participants subsequently ranked their psilocybin session among the single most meaningful experiences of their entire lives, with 24 volunteers placing it within their personal top five life events.
Blurred Boundaries
When Stoliker’s team first evaluated the brain scans using conventional neuroimaging metrics, the initial findings seemed to confirm the classic view of psychedelic disruption.
By measuring global functional connectivity—a metric assessing how significantly individual patches of the cerebral cortex influence activity across the rest of the brain—the researchers observed marked changes during eyes-closed states. Under psilocybin, primary sensory regions responsible for processing direct external inputs lost their typical dominance over the brain’s global signaling. In contrast, associative brain regions—which handle higher-level integration, abstract thought, and memory—gained significant sway.
