“Psilocybin, in contrast to any other drug we’ve tested, has this massive effect on the whole brain that was pretty unexpected,” said Dr. Nico Dosenbach, a professor of neurology at Washington University and a senior author of the study. “It was quite shocking when we saw the effect size.”
https://www.nytimes.com/2024/07/17/health/psilocybin-psychedelic-mushrooms-brain.html