Theories of Consciousness

Testability & Evidence β€” logical structure, neuroscience methods, and what the data says

Built from Closer to Truth Β· Stanford Encyclopedia of Philosophy Β· Primary Literature Β· Last updated July 2026

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Theories Catalogued
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Testable (Now)
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Testable (In Principle)
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Metaphysical Only

What this is

A systematic analysis of theories of consciousness β€” what gives rise to subjective experience β€” assessed along three dimensions:

  • Logical structure: Each theory's argument reconstructed in Fitch-style natural deduction, with vertical scope bars showing which assumptions are active at each step
  • Testability: Each conclusion scored on a formal 5-dimension rubric (specificity, measurability, perturbability, falsifiability, discriminability) β€” assessing whether it could be tested with current neuroscience methods, not whether it has been
  • Evidence: What the empirical data actually shows β€” including the 2025 Cogitate Consortium adversarial collaboration that directly tested the two leading theories

πŸ”¬ Landmark: The Cogitate Consortium (2025)

The first large-scale, preregistered adversarial collaboration directly comparing Integrated Information Theory (IIT) and Global Neuronal Workspace Theory (GNWT) β€” the two leading empirically-testable theories of consciousness.

🟑 IIT: Posterior cortex contains conscious content (partially confirmed), BUT sustained synchronization within posterior cortex was NOT found (key prediction failed), and maximum integrated information in posterior cortex was NOT confirmed.
πŸ”΄ GNWT: Lack of ignition at stimulus offset (challenged), limited prefrontal representation of conscious content (challenged), global broadcasting inconclusive.
πŸ“Š Methods: fMRI, MEG, and intracranial EEG across 256 participants. Preregistered predictions with pass/fail criteria agreed ex-ante by both theory proponents.

Cogitate Consortium, Ferrante et al. (2025). Nature, 642, 133–142. DOI: 10.1038/s41586-025-08888-1

"Whereof one cannot speak, thereof one must be silent." β€” Wittgenstein, Tractatus Logico-Philosophicus, Β§7

Our guiding principle: theories that make no testable predictions are not wrong β€” they are not in the game. We catalogue them, but our energy goes where evidence can reach.

Testability Spectrum

Each theory is scored on a formal 5-dimension rubric assessing whether its conclusions can be tested with current neuroscience methods. Testability is about what could be tested, not what has been tested β€” a famous theory with many papers is not necessarily testable if its core constructs cannot be measured.

Not Testable In Principle Weakly Testable Strongly Testable

Theories by Tier

All Catalogued Theories

Click any theory to see its argument structure, scope line, and evidence assessment.

Theory Proponent Category Testability Score

Empirical Evidence for Theories of Consciousness

This tab compiles the actual experimental and observational evidence that has been brought to bear on testable theories of consciousness.

Premise-by-Premise Evidence Database

Each theory's premises are tested against evidence from independent sources β€” papers that test the underlying physics, pharmacology, or neuroscience without necessarily referencing the consciousness theory. This avoids publication bias: nobody publishes "Orch-OR failed," but physicists routinely test quantum decoherence in biological systems.

🟒 Supports   🟑 Supports with caveats   πŸ”΄ Refutes   🟠 Mixed   βšͺ Untestable   πŸ”΅ Theoretical prediction

What Is Consciousness?

Before asking what creates consciousness, we need to ask what consciousness is. Theories of consciousness implicitly or explicitly adopt a definition. If we don't make that definition explicit, we risk talking past each other β€” and we miss a powerful form of critique: the overgeneration test.

Method

Sources

Scope Lines (Fitch-Style)

Each theory's argument is reconstructed in Fitch-style natural deduction β€” the notation used in formal logic textbooks. Vertical scope bars on the left show which assumptions are active at each step. Nested bars mark sub-derivations that depend on additional auxiliary assumptions. Conclusions are written in abstract variables, with a symbol legend below each proof.

This makes visible which assumptions each conclusion depends on β€” and therefore which assumptions, if wrong, would collapse the argument. The scope line is the backbone of our testability assessment: we score each conclusion based on whether it can be tested with current neuroscience methods.

Testability Rubric

Each conclusion in a theory's scope line is scored on five dimensions (0–1). The theory-level score is a weighted mean (core conclusions weighted 2Γ—, derived conclusions 1Γ—). Citation count and publication volume do NOT enter the score β€” a famous theory with many papers is not necessarily testable if its core constructs cannot be measured.

Dimension Question Score 1.0 Score 0.0
D1. Specificity Does the conclusion predict something about a brain area, circuit, or measurable quantity? Precise quantitative prediction No empirical prediction
D2. Measurability Can current neuroscience methods measure the predicted quantity? Routinely measured (fMRI, EEG) Not measurable with any existing tech
D3. Perturbability Can we causally intervene on the mechanism (TMS, pharmacology, lesions)? Selective perturbation in humans Cannot perturb the core mechanism
D4. Falsifiability Is there a clear disconfirming outcome, or can the theory absorb any result? Clear falsification criterion Any outcome can be reinterpreted
D5. Discriminability Does the prediction differ from rival theories? Unique to this theory Shared by all theories

Per-conclusion testability = mean(D1, D2, D3, D4, D5). Theory-level = weighted mean across conclusions (core 2Γ—, derived 1Γ—).

Neuroscience Methods Toolkit

The rubric is grounded in what current neuroscience can actually do:

PERTURBATION

TMS Β· tACS/tDCS Β· Pharmacological (anesthesia, psychedelics) Β· Lesion studies Β· DBS Β· Optogenetics (animal)

MEASUREMENT

fMRI Β· EEG Β· MEG Β· ECoG/iEEG Β· Single-unit Β· Calcium imaging (animal) Β· PET Β· fNIRS

STATE COMPARISONS

Sleep stages Β· Anesthesia dose-response Β· Disorders of consciousness (coma, VS, MCS) Β· Psychedelic states Β· Dreaming

PERCEPTUAL PARADIGMS

Binocular rivalry Β· Visual masking Β· Attentional blink Β· No-report paradigms Β· Change blindness

Testability Tiers

  • Strongly testable (0.75–1.0): Makes quantitative, falsifiable predictions testable with current neuroimaging/physics technology
  • Weakly testable (0.50–0.74): Makes predictions that are testable in principle and partially testable now, but core claims remain difficult to access empirically
  • Testable in principle (0.25–0.49): Makes predictions that could be tested with foreseeable technology but have not yet been adequately tested
  • Not testable (metaphysical) (0.00–0.24): Makes no empirical predictions. No conceivable observation could confirm or disconfirm the theory

Citation Verification

Every citation in this dashboard has been verified through Crossref, OpenAlex, and DataCite. Citations that could not be verified are flagged. No citation is presented as verified without checking.

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