Keynote series Dr. Adeel Razi — How does psilocybin rewire our brains?
By Alejandra Lopez-Castro
In recent years, psychedelics have made a comeback—not just in pop culture, but in science. One of the most fascinating substances being studied is psilocybin, the active ingredient in so-called “magic mushrooms.” A groundbreaking new study led by Dr. Adeel Razi and his investigation group, with Devon Stoliker as first author, revealed how this compound can dramatically change how our brains work, especially depending on the environment we’re in.
Researchers used the newest brain imaging technology to examine the effects of psilocybin on connectivity in the brain. They scanned 62 healthy adults with fMRI and EEG before and after giving them 19 mg of psilocybin. The volunteers were placed in contrasting settings—some remained motionless, some meditated, listened to music, or watched a film. What they found was remarkable. Nearly all described their experiences as profoundly significant—fully half reported that it was one of the five most significant experiences of their lives. So what was going on in their heads?
The study proved that psilocybin increases activity between brain areas involved in thinking, emotions, and imagination. At the same time, it reduces activity between areas handling sensory data, especially when the eyes are closed. The outcome is a strange state where inner and external events tend to blend together—a condition described by scientists as "embeddedness."
To find out more about these effects, the researchers used machine learning to analyze brain activity. What they discovered was that the more structured and dense the brain activity was, the more emotional and psychological effects there were. Interestingly, those who felt the effects at a later time than others had brain patterns that were like their normal state, which shows that timing plays a part in the way the brain reacts.
One month after the trip, participants reported that they had undergone lasting changes. They became more accepting of death and perceived more personal significance in life. These gains in psychology were correlated with the positive emotions they felt on the trip, which suggests that the emotional quality of the experience matters.
The study also explored how different environments influenced the brain's response. The interaction between the anterior hippocampus (a region related to memory) and the Default Mode Network (activated during introspection) differed based on whether the subjects were relaxed, meditating, listening to music, or watching a movie. This suggests that the brain's response to psilocybin is highly context sensitive.
One of the surprising findings was that meditation did not significantly influence how people felt about psilocybin. Music did, though. People who listened to music during their trip rated it more emotionally powerful and meaningful by as much as 25%. Music seemed to make their experience richer in a way that meditation did not.
At the technical level, psilocybin had an impact on the electrical patterns of the brain. It reduced slower brain waves (alpha and beta) and sped up faster ones (gamma), especially with eyes closed. The brain also produced more complex and diverse signals, suggesting it was functioning more creatively and flexibly.
Ultimately, this study provides a poignant demonstration of how psilocybin can alter the brain and how our surroundings, mindset, and even the music we're listening to can influence the experience.
Don't miss the interview with Dr. Razi that you'll find in the blog post. And don't miss the keynote talk this June at the OHBM Annual Meeting 2025
Source:
Stoliker, D., Novelli, L., Khajehnejad, M., Biabani, M., Barta, T., Greaves, M. D., ... & Razi, A. (2025). Psychedelics Align Brain Activity with Context. bioRxiv, 2025-03.
