Under the influence of psychedelics, the usual organization of the human brain loosens. That's what scientists have generally thought, with several studies showing that when we take these substances, the signals pinging between our neurons become more diverse and unpredictable. This increased entropy in our gray matter may underlie the strange, random, and often memorable experiences of psychedelic trips.

But in one of the largest neuroimaging studies on the effects of psilocybin to date, researchers uncovered a hidden order in the apparent chaos. The study, published in Nature, indicates that while psilocybin blurs some of the boundaries within the brain, our neurological reactions to what we're experiencing in that moment become even more distinct.

The researchers tracked moment-by-moment changes across 332 regions of the brain using functional magnetic resonance imaging and electroencephalography, two methods of measuring brain activity. The 62 participants, who had no prior experience with psychedelics, took 19 milligrams of psilocybin in an oral capsule and then meditated, listened to music, or watched a movie.

With the help of artificial intelligence, the researchers identified patterns in the brain for each kind of activity the participants were engaged in. But surprisingly, the more intense the psilocybin experience, the clearer those neural signals were. Rather than becoming lost in the midst of an increasingly unpredictable trip, reality seemed to be leaving a more distinct imprint.

These findings weren't just apparent in the biological measurements but also in participants' personal experiences. Those who exhibited the most defined patterns of brain activity also tended to describe more intense experiences of immersion and unity with the world around them, the boundaries between themselves and the environment sometimes feeling blurred.