Entropic Brain Hypothesis
A neuroscientific framework proposing that the quality of consciousness is related to the entropy (information-theoretic complexity) of brain activity. Normal waking consciousness occupies a 'critical' zone of moderate entropy, maintained by the default mode network (DMN). Psychedelics increase neural entropy — measured via Lempel-Ziv complexity in EEG — by disrupting top-down predictive models, producing richer, less constrained conscious states. The REBUS (Relaxed Beliefs Under Psychedelics) extension proposes that psychedelics relax the precision weighting of prior beliefs, allowing bottom-up sensory information to reshape rigid cognitive patterns.
Core Propositions
Uncited. These state what the framework asserts. They are not findings Psychedex has verified, and no reference is attached to any of them.
Effects
DMN disruption → loss of self-model coherence. Measurable: ego dissolution scores correlate with decreased DMN functional connectivity (Carhart-Harris et al., 2016).
Increased entropy in visual cortex amplifies pattern completion — the brain over-interprets noise as structure, producing enhanced pattern perception and pareidolia.
Entropy increase without sufficient 'letting go' creates prediction error overload. The brain's model of reality is dissolving faster than the system can accommodate.
Relaxed precision weighting on prior beliefs (REBUS) allows novel conceptual associations that would normally be suppressed by top-down processing.
Substances
LSD produces the highest measured increase in neural entropy of any psychedelic studied. Primary research substrate for the original 2014 entropic brain paper.
Psilocybin produces measurable DMN disruption and increased Lempel-Ziv complexity. The 2016 Carhart-Harris fMRI study on psilocybin was foundational for the REBUS extension.
DMT produces the most intense entropy increase per unit time — consistent with its reputation as the most intense psychedelic experience. Short duration makes it ideal for neuroimaging studies.
NMDA antagonism produces entropy changes through a different mechanism than serotonergic psychedelics — disruption of glutamatergic prediction rather than serotonergic gating.
Framework record
An interpretive framework: a lens for reading experience, not a measured record. Its claims are the framework’s own. No references are attached to this entry on Psychedex, and nothing on this page has been verified against a source here.
- references
- none on file
- epistemic status
- Emerging
- revision
- 1
- published
- not recorded
- content origin
- LLM generated
- psx id
- FRM-entropic-brain
Origin
Proposed by Robin Carhart-Harris in 2014 at Imperial College London, building on Aldous Huxley's 'reducing valve' metaphor and modern neuroimaging of psychedelic states. Extended with the REBUS model in 2019 (Carhart-Harris & Friston).
Key Figures
Key Texts
The framework’s own foundational literature, not sources cited for this entry.
Related Frameworks
EBH's 'relaxed beliefs' maps to IFS's 'Managers stepping back.' Both describe psychedelic therapeutic action as the temporary relaxation of rigid protective structures.