Head to head
Crick and Koch’s NCC vs Functionalism
Crick and Koch’s Neural Correlates of Consciousness (NCC) and Functionalism, compared field by field from their entries in the Atlas.
At a glance
- Both belong to the Materialism family in Kuhn's Landscape of Consciousness.
- Both treat consciousness as emergent.
- They give the same kind of answer on AI consciousness, mind uploading and meaning and purpose.
- On life after death, Crick and Koch’s NCC says “No” and Functionalism says “Conditional”.
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The claim
In brief
Crick and Koch’s NCCThis theory proposes a scientific agenda to identify the Neural Correlate of Consciousness (NCC), defined as the minimum activities in the brain that are jointly sufficient and necessary for any specific conscious perception or subjective experience. It asserts that consciousness is entirely physical and can be fully reduced to these specific brain activities.
FunctionalismFunctionalism posits that mental states are defined by their causal relations to one another, to sensory inputs, and to behavioral outputs, independent of the physical medium (substrate) in which they are realized. The essence of consciousness is determined by how mental states function or operate, rather than by what they are materially composed of.
What consciousness is
Crick and Koch’s NCCConsciousness (phenomenal consciousness/qualia) is identified as the Neural Correlate of Consciousness (NCC), the precise minimum pattern of neural activity in the brain necessary and sufficient for subjective experience.
FunctionalismMental states are identified as functional states, constituted by their causal relations, roles, results, and outputs, implying they are realizable in any substrate that supports those functions.
Big questions
Can AI be conscious?Both agree
Crick and Koch’s NCCYesIf consciousness is entirely reducible to physical organizational patterns (NCC), then non-biological systems capable of replicating those precise patterns should also become conscious, barring technological constraints.
FunctionalismYesFunctionalism holds that consciousness is based on function, not biology. If the correct functions can be realized computationally in non-biological substrates, AI consciousness is possible in principle and certain if Materialism is true.
Crick and Koch’s NCCNoAs a Materialist theory, consciousness is wholly dependent on the physical brain; cessation of brain function entails the end of consciousness.
FunctionalismConditionalAs a physicalist theory, consciousness is tied to the substrate. Survival beyond death of the biological body is only possible if the functional mental state can be successfully transferred (uploaded) to a new, continuing substrate (virtual immortality).
Could a mind be uploaded?Both agree
Crick and Koch’s NCCYesIf the NCC states can be perfectly measured and replicated in a digital or artificial medium (mind uploading), the resulting system would be functionally and phenomenally identical, achieving virtual immortality in principle.
FunctionalismLikelyFunctionalism serves as the theoretical basis for virtual immortality. If the functional role of the mental self can be perfectly duplicated and uploaded to a new medium, the first-person mental self is preserved.
Does it give life meaning?Both agree
Crick and Koch’s NCCHumanistic onlyConsistent with Materialism, consciousness is a biological product of evolution and physics, conferring no ultimate cosmic meaning or teleology beyond that which humans create for themselves.
FunctionalismHumanistic onlyFunctionalism describes the mechanism by which mind/consciousness operates within a physical world, providing capacities for agency and reflection, but offers no rationale for ultimate cosmic meaning or teleology, aligning with the general stance of Materialism.
Nature of mind
Ontology
Crick and Koch’s NCCReductive Physicalism/Materialism. The NCC approach is considered macroscopic materialism.
FunctionalismPhysicalism (broadly, agnostic to substance). The theory is classified under Materialism, but it is metaphysically agnostic regarding nonphysical substances, focusing primarily on the functional description of mental states.
Mind and body
Crick and Koch’s NCCIdentity Theory. Mental states are wholly identical to and fully explained by the physical NCC states.
FunctionalismMental states are functional states identical to the functional roles that are realized or instantiated in a physical substrate, leading to 'functional state identity theses'.
Fundamental or emergent
Crick and Koch’s NCCEmergent
FunctionalismEmergent. Consciousness arises from the functional organization realized by a sufficiently complex substrate (like neural tissue or computer chips).
Qualia
Crick and Koch’s NCCQualia (the qualitative feel of experience) are identified with the minimum neural activities (NCC) that are jointly sufficient for specific conscious perception, although the mechanism for this identity remains the central 'hard problem' challenge.
FunctionalismThe theory traditionally struggles to account for phenomenal qualia, often addressing them by asserting that the qualitative feel is entirely exhausted by the functional role, or by coupling with representational theories.
How it works
Mechanism
Crick and Koch’s NCCThe search for and definition of the Neural Correlate of Consciousness (NCC): the specific minimum neural activities necessary and sufficient for subjective experience.
FunctionalismThe principle of multiple realizability, stating that mental state realization is independent of the physical substrate, contingent only upon the required function being instantiated.
Where it is
Crick and Koch’s NCCLocalized in specific brain areas. Early candidates included the claustrum (as a 'conductor' coordinating percepts); later candidates focused on the posterior cerebral cortex (temporo-parietal-occipital hot zone).
FunctionalismDistributed wherever the functional organization is successfully realized, regardless of whether the substrate is neural tissue or hardwired computing components.
What it does
Crick and Koch’s NCCConsciousness is directly caused by, and is identical to, the NCC activity. NCC mechanisms (spikes, flows, circuits) are seen as constitutive of phenomenal consciousness.
FunctionalismFunctions, roles, and outputs are dispositive. Mental states are causally effective because they are defined by their causal relations within the system (functional role).
Evidence and criticism
Testability
Crick and Koch’s NCCEmpirically testable. The search for the NCC is defined as a scientific program seeking testable biological bases for consciousness.
FunctionalismConceptually and empirically testable. Thought experiments (like substrate replacement) probe its conceptual limits, and computational realization (AI) tests its empirical application.
Tests so far
Crick and Koch’s NCCIdentifying specific clusters of neurons or brain regions (like the claustrum or posterior cortex) that are active during conscious experience.,Measuring electrophysiological activity (e.g., action potentials and neural circuits).
FunctionalismThe silicon chip replacement thought experiment is used conceptually to test whether phenomenal consciousness is preserved when the functional role is maintained across a change in substrate.
Criticisms
Crick and Koch’s NCCThe primary tension is the 'explanatory gap': identifying a correlation (NCC) does not explain the identity statement of how physical activity (spikes/chemicals) literally generates phenomenal feel (qualia). The failure to identify a 'clear' NCC after decades of research is a practical limitation.
FunctionalismIt is criticized heavily for failing to account for phenomenal consciousness (qualia) by describing only the functional role, leading to the 'hard problem' challenge that functional roles may not exhaust the nature of conscious experience.
Sources
Key sources
Crick and Koch’s NCC
- Towards a neurobiological theory of consciousness, F. Crick and C. Koch (1990)
- What is the function of the claustrum?, F. Crick and C. Koch (2005)
- The Quest for Consciousness: a Neurobiological Approach, C. Koch (2004)
Functionalism
- What is functionalism? (N. Block) (1980)
- What Is Functionalism? Consciousness, Function, and Representation (N. Block) (2007)
- Functionalism (J. Levin) (2023)