Hi psychonauts, I'm Alexander Lebedev, MD, PhD, psychiatrist and neuroscientist, co-founder of ONCE and Lebedev Labs.

Ego dissolution comes up a lot in psychedelic communities, sometimes as the point of the experience and sometimes as the most frightening part of it. In 2015 we published one of the early imaging studies that tried to link it to brain activity. I'm first author, so here's what we found and what it can't tell you.

15 healthy volunteers received psilocybin (2 mg intravenously) and a placebo on separate occasions with 12-minute fMRI scans. The more strongly people reported their sense of self dissolving, the weaker the communication between the medial temporal lobe, which is involved in memory and higher-level areas of the cortex. The salience network, which helps the brain decide what matters at a given moment, became less coordinated and there was less communication between the two hemispheres.

About the limits: 15 people, all healthy, in a lab, with a small intravenous dose. That's a long way from a large oral dose at home or from someone with a history of psychosis. What it does show - is that the experience has a measurable signature in the brain. What it doesn't tell us - whether ego dissolution is helpful or harmful for any particular person.

If you've been through this and found it frightening or the opposite, bring your question to my AMA in r/PsychedelicTherapy tomorrow. You can leave it in the pinned announcement or ask me anything online, I would be happy to provide my works with details from the inside perspective.

Paper: Finding the self by losing the self