In 2012, Robin Carhart-Harris and his team at Imperial College London published a study in the Proceedings of the National Academy of Sciences that produced one of the most counterintuitive findings in the history of neuroscience.
They gave psilocybin — the active compound in psychedelic mushrooms — to volunteers inside an fMRI scanner and watched what happened in the brain. The expectation, based on decades of research with other psychoactive substances, was that a drug producing such vivid, intense subjective experiences would show increased brain activity. More experience should mean more neural firing. The brain should light up.
It didn't.
Psilocybin decreased brain activity. Specifically, it reduced blood flow and functional connectivity in the Default Mode Network — the same network that earlier essays in this publication have discussed as the brain's self-narration engine. The network that generates your sense of being a continuous, specific person. The network that produces the inner monologue, replays memories, projects into the future, and maintains the ongoing story of "me."
The greater the reduction in DMN connectivity, the more intense the subjective experience the volunteers reported. And the subjective experience they described, consistently, was ego dissolution — the loosening or temporary disappearance of the sense of self.
Less neural activity. Less self. More experience.
The network that builds you
To understand why this matters, you need to understand what the Default Mode Network does when it's working normally.
The DMN is a set of brain regions — the medial prefrontal cortex, the posterior cingulate cortex, and the angular gyrus, among others — that become active when you're not focused on any external task. When you're solving a maths problem or tracking a moving object, the DMN goes quiet. When you stop — when you're sitting on the bus, lying in bed, staring out a window — it turns on.
What it produces, in those idle moments, is you.
Not the biological you — the body, the heartbeat, the breathing. The narrative you. The story of who you are, where you've been, what you think about things, what you're going to do tomorrow, what you should have said yesterday, and whether you're a good person. The DMN is the infrastructure of self-reference. It's the part of the brain that generates the feeling that there is a continuous "I" at the centre of your experience, persisting through time, authoring your thoughts, owning your memories.
When the DMN is active — which is most of the time you're not absorbed in a task — you are, in a very literal neurological sense, constructing yourself. And when the DMN goes quiet, as it does during intense focus, flow states, and now, demonstrably, under psilocybin — the construction pauses. The "me" thins. And what remains is experience without an experiencer.
What the volunteers said
The subjective reports from Carhart-Harris's studies — and from the dozens of studies that followed at Johns Hopkins, NYU, Zurich, and Maastricht — are remarkably consistent.
People describe the boundaries of the self loosening. The feeling of being a separate person, contained in a body, looking out at a world — that feeling relaxes. It doesn't vanish into unconsciousness. The person is still awake, still aware, still having experience. But the usual frame — "I am here, the world is there, and I am the one experiencing it" — softens. The border between inside and outside becomes less defined. Some people describe a feeling of merging with their surroundings. Others describe the self becoming transparent — still present but no longer solid.
In 2020, Natasha Mason and her team at Maastricht University published a study in Neuropsychopharmacology that added a chemical dimension to this picture. They found that the quality of ego dissolution depends on where the glutamate changes occur. Lower glutamate in the hippocampus correlated with positively experienced ego dissolution — the oceanic, expansive, "everything is connected" version. Higher glutamate in the medial prefrontal cortex correlated with negatively experienced ego dissolution — the anxious, disorienting version where the self dissolves but the experience feels threatening rather than liberating.
Same phenomenon. Different chemistry. Different experience. The self can dissolve into light or into darkness, depending on what's happening underneath.
The meditators got there first
Here's where the story converges with territory this publication has been exploring since its first essay.
In 2011, a year before the psilocybin studies, Judson Brewer and his team at Yale published a study showing that experienced meditators have reduced DMN activity compared to non-meditators. The same network. The same reduction. The same direction.
The meditators hadn't taken anything. They'd sat. For years, in some cases decades, they'd practised sustained attention — watching the breath, watching thoughts arise and pass, watching the sense of self come and go. And over time, the DMN — the self-narrating network — had become less dominant. Not damaged. Not offline. Less active. Quieter.
The subjective reports from long-term meditators are, notably, very similar to the subjective reports from psychedelic experiences. The sense of self loosening. The boundaries between observer and observed becoming less fixed. A quality of awareness that is spacious rather than located. The feeling of being present without being someone specific.
In 2019, a team at the University of Zurich led by Lukasz Smigielski combined the two. They gave psilocybin to experienced meditators during a meditation retreat. The result: enhanced ego dissolution during the session, and lasting changes in self-consciousness and DMN connectivity that persisted for weeks after the compound had left the body. The meditation and the psilocybin didn't just add to each other. They multiplied. The contemplative practice gave the psychedelic experience a framework, and the psychedelic gave the contemplative practice a depth charge.
Two doors, one room
The convergence is striking, and it deserves to be stated plainly.
Two completely unrelated approaches — one chemical, one contemplative — produce the same neural signature (reduced DMN connectivity), the same subjective report (ego dissolution, loosening of self-boundaries), and point at the same conclusion: the sense of being a continuous, specific self is not a fixed property of consciousness. It's a pattern the brain generates. And the pattern can be interrupted.
Psilocybin interrupts it chemically, in minutes. Meditation interrupts it attentionally, over years. The speed is different. The entry point is different. The preparation is different. But the room they arrive in looks, from every angle the neuroscience can measure and every description the participants can give, like the same room.
This is not a small finding. It suggests that the self — the thing you spend your entire life maintaining, defending, improving, worrying about — is not a fact about consciousness but a process the brain performs. A construction. An activity. And like any activity, it can pause.
What the traditions already knew
The contemplative traditions — Advaita Vedanta, Zen Buddhism, certain strands of Sufism — have been saying this for centuries. Not as neuroscience. As observation.
Ramana Maharshi's central method was to send attention back toward its own source. Follow the "I" thought to its origin. Who am I? Not the body, not the thoughts, not the emotions — but the awareness in which all of these appear. When you look for the "I" directly, he said, you don't find a thing. You find awareness itself — present, luminous, and without a centre.
The Zen tradition describes this as kensho — seeing one's true nature. Not an experience the self has, but the seeing through of the self, revealing that what you took to be solid was always transparent. Always a construction. Always held in place by activity, not by substance.
The neuroscience doesn't validate these traditions in any simple sense. A reduced DMN reading on an fMRI machine is not the same as enlightenment, and claiming it is would be both scientifically careless and contemplatively naive. But the convergence is hard to ignore. Two completely different methods of inquiry — one using scanners and molecules, the other using sustained attention and radical honesty — arriving at the same observation: the self is a process, not a thing. And it can be seen through.
The difference that matters
There is, however, a difference between the two doors, and it's one that the psychedelic enthusiasm of the current moment sometimes obscures.
Psilocybin interrupts the DMN from outside. It reduces the network's connectivity through a chemical mechanism — agonism at the 5-HT2A serotonin receptor — that the person has no control over. The self dissolves because the chemistry that sustains it has been altered. When the compound is metabolised and the chemistry returns to baseline, the self-pattern typically reassembles. The experience was real. The insight may persist. But the mechanism was external.
Meditation — at least in the way the serious traditions describe it — works differently. It doesn't override the self-pattern. It sees through it. The meditator doesn't take a substance that turns the DMN down. The meditator pays such close, sustained attention to the process of self-construction that the process becomes visible — and in becoming visible, loses some of its authority. The self doesn't dissolve because something blocked it. It becomes transparent because someone looked at it long enough to see what it was made of.
The distinction is between having an experience and developing a capacity. Psilocybin gives you the experience of ego dissolution. Meditation, over time, develops the capacity to recognise the self as a construction in ordinary, unaltered consciousness — while cooking breakfast, while answering email, while arguing with someone you love.
Both are valuable. But they're not the same.
What the convergence means for you
The practical implication of all of this is simpler than the neuroscience makes it sound.
The sense of being "you" — the continuous, specific, located feeling of being a person with a name and a history and a set of problems — is generated by a network of brain regions that can be measured, mapped, and modulated. It's not the ground of consciousness. It's a pattern consciousness produces. A very useful pattern — it allows you to navigate the world, maintain relationships, plan for the future, learn from the past. But it's a pattern, not a fact. An activity, not an identity.
You know this already, if you've been paying attention. You've felt it in moments of absorption — music, physical exertion, the seconds after waking before the "I" reassembles. You've felt the self thin and the world brighten in the same instant, and you've felt the self return and the world narrow again. These weren't malfunctions. They were glimpses of what consciousness looks like when the self-generating network takes a breath.
The psychedelic research is photographing what the contemplative traditions pointed at. The meditators are verifying what the scanners are measuring. And both are saying the same thing, in different languages, with different levels of precision and different kinds of evidence:
You are not the pattern. You are what remains when the pattern pauses.
And what remains — awareness, presence, the bare fact of being here — was never generated by the DMN. Was never a construction. Was never something that could dissolve, because it was never assembled in the first place.
The self comes and goes. What's aware of the self was here before it started, and will be here after it stops. Every night, in deep sleep. Every moment of genuine absorption. And now, measurably, reproducibly, in a scanner at Imperial College London — while a volunteer lies still and a molecule quietly turns down the volume on the story of "me."
Sources and further reading:
- Carhart-Harris et al., "Neural correlates of the psychedelic state as determined by fMRI studies with psilocybin," PNAS (2012) — the first major study showing psilocybin reduces DMN connectivity
- Carhart-Harris et al., "Neural correlates of the LSD experience revealed by multimodal neuroimaging," PNAS (2016) — confirming the same pattern with LSD
- Mason et al., "Me, myself, bye: regional alterations in glutamate and the experience of ego dissolution with psilocybin," Neuropsychopharmacology (2020) — on the chemistry of positive vs negative ego dissolution
- Brewer et al., "Meditation experience is associated with differences in default mode network activity and connectivity," PNAS (2011) — on experienced meditators showing reduced DMN activity
- Smigielski et al., "Psilocybin-assisted mindfulness training modulates self-consciousness and brain default mode network connectivity with lasting effects," NeuroImage (2019) — on combining psilocybin with meditation