One with the world? A new look at brains transformed by psychedelics.

For about a decade, the mainstream understanding has been that psychedelics cause chaos in the brain. Brain networks—the stable patterns of communication that handle vision, attention, or our sense of self, and more—loosen and start talking to each other all at once. EEG traces get noisier and more complex. “Think of the networks of the brain as highways,” says Devon Stoliker, a neuroscientist at Monash University. “Under psychedelics, these highways break down into many different directions.”

In a recent Nature study, Stoliker’s team designed an experiment to test whether these directions are truly chaotic and random. Researchers gathered 62 people who had never taken a psychedelic before, gave them 19 milligrams of psilocybin, a common psychedelic found in certain fungi, and scanned their brains. Then, they used AI to analyze the drugged and sober brain scans. What emerged was not exactly chaos.

Stoliker thinks chaos is not a satisfactory explanation for psychedelics’ effect on the brain. …