New research indicates that psilocybin-assisted mindfulness meditation is associated with changes in functional brain connectivity — and these changes are related to an altered state of consciousness known as ego dissolution. The findings appear in the journal NeuroImage.

A team of scientists from the University of Zurich were interested in investigating the topic because both psychedelic drugs and meditation have been shown to alter brain regions involved in self-awareness.

In the randomized, double-blind study of 38 experienced meditators, the researchers administered a single dose of psilocybin or a placebo to participants during a 5-day mindfulness retreat. Six hours after receiving psilocybin or placebo, the participants completed an assessment of altered states of consciousness.

The participants also underwent fMRI brain scans the day before and the day after the retreat to investigate changes in functional connectivity while resting, while engaging in focused attention meditation, and while engaging in open awareness meditation.

The researchers were particularly interested in a network of interacting brain regions known as the default mode network, which has been associated with processing feelings of self.

Compared to those who received a placebo, those who received psilocybin were more likely to feel like the boundary that separates them from the rest of the world had been dissolved — an altered state of consciousness known as oceanic self-boundlessness or ego dissolution.

The researchers found that this altered state of consciousness was associated with changes in brain connectivity. In particular, psilocybin-induced ego dissolution was associated with a decoupling of functional connectivity between the medial prefrontal cortex and posterior cingulate cortex regions of the default mode network while engaging in open awareness meditation.

“We here report for the first time psilocybin-induced functional connectivity changes in self-referential brain networks in a group of experienced meditators after a mindfulness retreat,” the researchers said.

Psilocybin-induced ego dissolution and changes in brain connectivity also predicted positive changes in attitudes about life, self, social behavior, mood, and spirituality at a 4 months follow-up assessment.

“An experience of ego dissolution may further imply cognitive reappraisals, reifications, self-inquiry, or insights and contribute to enduring psychological changes,” the researchers wrote in their study. “Our double-blind study presents a notable case because its participants were primarily in middle adulthood and already engaged in meditative practices, and yet the psilocybin-treatment group still reported a significant beneficial effect of the retreat.”

The results are largely in line with a previous study that examined the combination of psilocybin and meditation.

That study, published in the Journal of Psychopharmacology in 2017, found that psilocybin-occasioned experience, in conjunction with meditation and other daily spiritual practices, were associated with enduring increases in traits such as altruism, gratitude, forgiveness, and interpersonal closeness, as well as decreases in fear of death.

The new study, “Psilocybin-assisted mindfulness training modulates self-consciousness and brain default mode network connectivity with lasting effects“, was authored by Lukasz Smigielski, Milan Scheidegger, Michael Kometer, and Franz X. Vollenweider.