Prediction 1: Psychedelics Alleviate Anosognosia¶

Administration of psychedelic substances at sub-ego-dissolution doses to patients with anosognosia should produce a measurable, dose-dependent, temporary increase in explicit awareness of their deficits.

This is a cross-domain prediction -- it connects psychopharmacology and clinical neurology through a single principle, variable permeability. IIT, GNW, HOT, and AST are silent on why a psychedelic should help an anosognosia patient recognize their paralysis; predictive processing can reach a coarse version of it, and FMT's distinctive content lies in the fine structure set out below.

The Mechanism: Permeability as a Two-Way Street¶

The prediction rests on the interaction of two phenomena that the Four-Model Theory explains through the same mechanism operating in opposite directions:

Anosognosia is a local decrease in implicit-explicit permeability. The ISM registers the deficit -- the body schema contains accurate information about the paralysis, the proprioceptive loss, or the visual field cut. But the transfer of this specific information to the ESM is blocked. The patient's substrate knows about the deficit; the patient's conscious self-model does not. The result is the characteristic clinical picture: a hemiplegic patient who sincerely denies being paralyzed, or a cortically blind patient who insists they can see.

Psychedelics globally increase permeability, as described in the theory's account of psychedelic phenomenology. They weaken the implicit-explicit boundary across the board, allowing normally unconscious processing stages to reach the conscious simulation.

The prediction follows directly: if anosognosia is a local permeability block, and psychedelics produce a global permeability increase, then the global increase should compensate for the local block -- allowing deficit information to reach the ESM. The patient should, temporarily and dose-dependently, become aware of their condition.

A boundary condition applies. The global increase can compensate only if the tissue carrying the deficit information is structurally intact. If the lesion has destroyed the pathway that would transmit it from ISM to ESM, rather than merely blocking the transfer, increased permeability has nothing to propagate. The prediction therefore applies most strongly to disconnection-type anosognosia, and lesion mapping can classify patients by pathway integrity: the effect should be strongest in disconnection cases and absent or attenuated where the relevant pathway is destroyed.

Figure¶

graph LR
    subgraph "Anosognosia — Local Block"
        ISM_A["ISM\nRegisters deficit\n(paralysis, blindness)"]
        BLOCK["Local Permeability\nBlock"]
        ESM_A["ESM\n'I am fine'\n(deficit denied)"]
        ISM_A -->|"deficit info"| BLOCK
        BLOCK -.->|"❌ blocked"| ESM_A
    end

    subgraph "Psychedelic Intervention"
        PSY["Psilocybin\n(sub-ego-dissolution dose)"]
        GLOBAL["Global Permeability\nIncrease"]
        PSY -->|"increases"| GLOBAL
    end

    subgraph "Predicted Outcome"
        ISM_B["ISM\nRegisters deficit"]
        COMP["Local block\ncompensated by\nglobal increase"]
        ESM_B["ESM\n'I am paralyzed'\n(deficit recognized)"]
        ISM_B -->|"deficit info"| COMP
        COMP -->|"✓ reaches ESM"| ESM_B
    end

    GLOBAL -->|"compensates for"| COMP

    style BLOCK fill:#F44336,stroke:#333,color:#fff
    style COMP fill:#4CAF50,stroke:#333,color:#fff
    style ESM_A fill:#FF9800,stroke:#333,color:#fff
    style ESM_B fill:#4CAF50,stroke:#333,color:#fff
    style PSY fill:#9C27B0,stroke:#333,color:#fff

Anosognosia as a local permeability block (left) compensated by global psychedelic-induced permeability increase (center), producing temporary deficit awareness (right). The ISM contains accurate information throughout -- the bottleneck is transfer to the ESM.

Testability¶

The prediction is specific enough for clinical investigation:

Measurable outcome: Improvement in explicit awareness, quantifiable via established anosognosia assessment scales.
Dose-dependent: Higher sub-ego-dissolution doses should produce greater improvement, up to the threshold where ego dissolution itself introduces confounding effects.
Temporary: The effect should dissipate as the psychedelic clears the system, since the local permeability block is structural (lesion-based), not pharmacological.
EEG correlate: Improvement should correlate with EEG complexity increases over the lesioned hemisphere specifically, as the global permeability increase reaches the damaged region.
Safety: Psilocybin clinical trials already have extensive safety data at the relevant dose ranges, making initial case studies feasible within existing regulatory frameworks.

Falsification Conditions¶

The prediction specifies clear falsification criteria. If psychedelics increase global neural complexity without improving explicit awareness in anosognosia patients, the variable-permeability model is incomplete -- global permeability increase does not interact with local blocks as predicted. If the effect occurs but is not dose-dependent, the mechanism is different from what the theory proposes.

Distinguishing Power¶

IIT, GNW, HOT, and AST are silent on why a psychedelic should help an anosognosia patient: they lack the architectural feature (variable permeability of a defined boundary) that generates this cross-domain connection. Predictive processing is not silent. REBUS holds that psychedelics relax pathologically overweighted high-level priors, and anosognosia has a standing predictive-processing treatment as aberrant predictive coding (Fotopoulou, 2014), so the coarse version of this prediction is derivable from REBUS in one step. FMT's differential content is the fine structure: dose-dependent improvement at doses below the ego-dissolution threshold, correlation with complexity increases over the lesioned hemisphere specifically, and the disconnection-versus-destruction boundary condition -- none of which follows from prior relaxation alone.

Key Takeaway¶

Prediction 1 connects two clinically distinct phenomena -- psychedelic experience and anosognostic denial -- through the single principle of variable permeability operating in opposite directions. Its fine structure (sub-ego-dissolution dosing, lesioned-hemisphere complexity, the disconnection-versus-destruction boundary) is what separates it from the coarse version predictive processing can also reach, making it a distinctive empirical test of the Four-Model Theory.