The Default Mode Network: How Psychedelics, Meditation, and Shamanic States Dissolve the Ego

The Network That Builds Your “Self”

You have a storyteller living inside your skull. It runs constantly — narrating your life, reminding you who you are, comparing the present to the past, worrying about the future, maintaining the continuous narrative thread that you experience as “me.” This storyteller is not a metaphor. It is a measurable, mappable network of brain regions called the Default Mode Network (DMN), and it may be the single most important discovery in neuroscience for understanding consciousness, ego, and spiritual awakening.

The DMN was discovered accidentally. In the late 1990s and early 2000s, neuroimaging researchers noticed that certain brain regions were consistently more active when subjects were not performing any specific task — when they were daydreaming, mind-wandering, or simply resting in the scanner. Rather than a brain “at rest,” these regions formed a coherent, highly active network that appeared to be the brain’s default operating mode.

The key regions of the DMN include:

• Medial prefrontal cortex (mPFC) — self-referential thinking, autobiographical memory
• Posterior cingulate cortex (PCC) — the hub of the network, involved in consciousness and self-awareness
• Precuneus — self-consciousness, episodic memory retrieval
• Lateral temporal cortex — semantic memory, conceptual knowledge
• Angular gyrus — integrating different types of information into a coherent narrative

Together, these regions construct and maintain the ego — the continuous sense of being a separate self with a past, a future, preferences, fears, and a coherent identity. The DMN is, in a very real sense, the neural substrate of the “I.”

The Entropic Brain Hypothesis: Robin Carhart-Harris’s Revolution

In 2014, Robin Carhart-Harris and colleagues at Imperial College London published a landmark paper proposing the Entropic Brain Hypothesis — a comprehensive framework for understanding how psychedelics, meditation, and other altered states relate to consciousness. This theory has become one of the most influential models in consciousness research.

The core insight is elegant: consciousness exists on a spectrum of entropy (disorder, randomness, unpredictability). At one end is high entropy — maximum disorder, flexibility, and connectivity. At the other end is low entropy — maximum order, rigidity, and compartmentalization.

Secondary Consciousness (Low Entropy). Ordinary adult waking consciousness is characterized by relatively low entropy. The DMN operates as a master controller, imposing top-down constraints on neural activity, maintaining rigid boundaries between brain networks, filtering and predicting incoming information, and sustaining the narrative self. This mode is efficient for navigating the everyday world but comes at a cost: rigidity, habitual thinking, rumination, and the persistent illusion of being a separate self cut off from the world.

Primary Consciousness (High Entropy). Psychedelic states, deep meditation, shamanic trance, and mystical experiences are characterized by higher entropy. The DMN loosens its grip, boundaries between brain networks dissolve, information flows more freely, novel connections form between previously isolated neural populations, and the rigid narrative self softens or dissolves entirely. This is what Carhart-Harris calls “primary consciousness” — a more fluid, interconnected, and unconstrained mode of awareness.

The spectrum between these poles maps remarkably well onto both clinical psychiatry and contemplative traditions:

Low Entropy (Too Rigid)	Optimal Range	High Entropy (Expanded)
Depression, addiction, OCD, rigid rumination	Healthy flexible cognition	Psychedelic states, mystical experience, shamanic trance
DMN hyperactivity	DMN modulated	DMN suppressed
Ego rigid and dominant	Ego flexible	Ego dissolved or transcended
Narrow, repetitive thought patterns	Creative, adaptive thinking	Unbounded, visionary awareness

How Psychedelics Suppress the DMN

The mechanism by which psychedelics produce their characteristic effects is now well understood at the network level. Classic psychedelics (psilocybin, LSD, DMT, mescaline) bind to 5-HT2A serotonin receptors, which are densely concentrated in the cortical regions of the DMN.

The result is a dramatic reduction in DMN activity and connectivity. The network that maintains the ego literally quiets down. Simultaneously:

Global connectivity increases. Brain regions that normally do not communicate begin exchanging information. The visual cortex talks to the auditory cortex. The emotional centers communicate directly with abstract reasoning centers. The brain becomes, temporarily, a more interconnected system.

Network boundaries dissolve. The normally distinct functional networks of the brain (default mode, salience, executive, sensory) lose their sharp boundaries. Information flows more freely across the entire brain.

Entropy increases. The brain’s activity becomes more unpredictable, more complex, and richer in information content. Psychedelics produce an “entropic” brain state characterized by compromised modular but enhanced global connectivity.

Ego dissolution occurs. The subjective correlate of DMN suppression is the experience of ego dissolution — the feeling of “oneness with the universe,” the loss of the boundary between self and world, the dissolution of the narrative “I.” This experience, reported across cultures and centuries by mystics, meditators, and psychedelic users, now has a precise neurological correlate: the disintegration of the DMN and its decoupling from medial-temporal brain regions.

A systematic review of DMN modulation by psychedelics published in 2023 confirmed these findings across multiple substances and study designs. The consistency of the effect is remarkable: whether the substance is psilocybin, LSD, DMT, or ayahuasca, the pattern is the same — DMN suppression, increased global connectivity, and ego dissolution.

Meditation and the DMN: The Slow Path to the Same Destination

What psychedelics achieve in minutes, contemplative practice achieves over years — but the neurological destination is strikingly similar.

Long-term meditators show reduced DMN activity during meditation, with experienced practitioners (10,000+ hours) showing DMN suppression even during ordinary waking states. Advanced practitioners in multiple contemplative traditions report experiences indistinguishable from psychedelic ego dissolution: the dissolution of the sense of a separate self, feelings of unity with all existence, and the recognition that the “self” was always a construction.

The key difference is control and integration. Meditation gradually trains the brain to modulate DMN activity intentionally, while psychedelics produce sudden, temporary, and dose-dependent suppression. Both approaches access the same underlying neural mechanism, but through different doors.

Functional neuroimaging studies have shown that experienced Zen meditators, Tibetan Buddhist monks, and practitioners of various contemplative traditions show the same pattern of reduced DMN connectivity and increased global neural integration seen in psychedelic states — just achieved through sustained practice rather than pharmacological intervention.

Shamanic States and the DMN: The Ancient Path

The 2021 EEG study of shamanic practitioners revealed that experienced shamans during drumming-induced trance achieved altered states of consciousness comparable to or exceeding those reported by volunteers under psychedelic influence. While the specific neural mechanisms differ (gamma enhancement and theta entrainment rather than direct 5-HT2A agonism), the functional outcome is similar: a reorganization of brain activity that loosens the grip of ordinary self-referential processing.

Shamanic trance, like psychedelic states, involves:

• Reduced dominance of analytical, self-referential thinking (DMN function)
• Enhanced imagistic, visionary, and intuitive processing
• Dissolution of the ordinary sense of self (the shaman “becomes” their power animal, merges with the spirit world)
• Access to information and perspectives unavailable in ordinary consciousness
• A felt sense of connection to something larger than the individual self

The shamanic traditions of every culture describe a process that maps directly onto DMN suppression: the shaman must “die” to their ordinary identity in order to travel between worlds. The initiatory death — experienced as dismemberment, dissolution, or descent into the underworld — is the phenomenological equivalent of ego dissolution. And the return — the reassembly of the self, the rebirth as a healer — is the reintegration of a more flexible, less rigidly bounded identity.

The Clinical Revolution: DMN Dysfunction and Mental Illness

The entropic brain hypothesis has profound clinical implications. Several major psychiatric conditions are now understood as disorders of DMN function:

Depression. Major depression is characterized by DMN hyperactivity — the self-referential network runs in overdrive, generating persistent rumination, negative self-evaluation, and a rigid, pessimistic narrative about self and future. Psilocybin therapy for depression works, at least in part, by temporarily suppressing the overactive DMN and allowing new neural patterns to form. Research at Johns Hopkins and Imperial College London has shown that psilocybin produces rapid and sustained antidepressant effects, with response rates far exceeding conventional medications.

Addiction. Addiction involves rigid, habitual neural patterns — the same DMN-dominated, low-entropy brain state seen in depression. Psychedelic-assisted therapy disrupts these patterns, creating a window of neuroplasticity in which new behaviors and self-concepts can take root. Johns Hopkins research on psilocybin for smoking cessation has shown remarkable preliminary results.

PTSD. Post-traumatic stress disorder involves the repeated, involuntary activation of traumatic memories — another form of DMN-mediated rigidity. The brain is stuck in a loop, and the DMN ensures that loop continues by maintaining a rigid self-narrative organized around the traumatic event. Both psychedelic therapy and EMDR may work partly by disrupting this DMN-maintained rigidity.

OCD. Obsessive-compulsive disorder is perhaps the most obvious example of excessive neural rigidity — the brain locked in repetitive patterns of thought and behavior. Preliminary psilocybin research for OCD has shown promising results, consistent with the entropic brain model.

The Ego Is Not the Enemy

A nuanced reading of both the neuroscience and the contemplative traditions reveals that the goal is not to permanently destroy the DMN or eliminate the ego. The ego — the sense of being a coherent, bounded self — is a functional adaptation. You need it to navigate traffic, hold down a job, and remember your name.

The problem arises when the ego becomes too rigid — when the DMN’s filtering and narrative-construction functions become a prison rather than a tool. When self-referential processing becomes rumination. When identity becomes a cage. When the story of “me” becomes so dominant that it blocks out the direct experience of being alive.

Both psychedelics and contemplative practices offer a way to loosen that grip — to experience, even temporarily, what lies beneath and beyond the constructed self. The shamanic traditions call this “dying before you die.” The Buddhists call it “no-self” (anatta). The psychedelic researchers call it “ego dissolution.” The neuroscientists call it “DMN suppression.”

They are all describing the same neural event from different angles: the moment when the brain’s self-narrating machinery quiets down, and awareness expands beyond the story of “me” into something vaster, more connected, and more alive.

Integration: Where the Magic Happens

The transformative potential of ego dissolution — whether achieved through psychedelics, meditation, breathwork, or shamanic practice — lies not in the experience itself but in what follows: integration. The DMN will rebuild. The ego will return. The question is whether it returns in the same rigid configuration or in a more flexible, compassionate, and expansive form.

This is why every authentic tradition — shamanic, contemplative, and now psychedelic-therapeutic — emphasizes preparation, guidance, and integration. The experience of egolessness is not the destination. It is the disruption that makes transformation possible. What you build in the aftermath is what matters.

The neuroscience of the DMN gives us a precise language for what the mystics have always taught: you are not who you think you are. The “you” that narrates your life is a construction — a useful, necessary, beautiful construction — but not the whole truth. Beneath the story, beneath the Default Mode Network’s ceaseless narration, there is awareness itself. And that awareness — boundless, luminous, and unowned — is what every contemplative tradition has pointed toward for millennia.

---

This article synthesizes research from Robin Carhart-Harris’s entropic brain hypothesis (2014), systematic reviews of DMN modulation by psychedelics, neuroimaging studies of meditation and shamanic states, and clinical research on psilocybin therapy at Johns Hopkins and Imperial College London.