Head to head
Crick and Koch’s NCC vs Recurrent Processing Theory
Crick and Koch’s Neural Correlates of Consciousness (NCC) and Lamme's Recurrent Processing Theory, 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, life after death, mind uploading and meaning and purpose.
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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.
Recurrent Processing TheoryLamme's Recurrent Processing Theory (RPT) posits that consciousness is both necessary and sufficient when reciprocal (recurrent) feedback connections occur among neural areas, particularly in sensory systems. This processing, which happens locally in sensory and post-sensory areas (Stage 3), generates phenomenal experience without requiring global broadcast access.
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.
Recurrent Processing TheoryConsciousness is identified as a specific recurrent processing state holding within relevant neural circuitry, such as the visual system.
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.
Recurrent Processing TheoryLikelyAs a Materialism Theory, AI consciousness must, in principle, be possible if the requisite pattern of recurrent processing could be artificially duplicated in a non-biological substrate.
Does consciousness survive death?Both agree
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.
Recurrent Processing TheoryNoConsciousness is tied to physical brain activity and specific neural circuitry (recurrent processing states), suggesting cessation upon bodily death.
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.
Recurrent Processing TheoryYesSince consciousness is the recurrent processing state itself, a perfect duplication of that process onto a new medium (upload) would generate the first-person self, enabling virtual immortality.
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.
Recurrent Processing TheoryHumanistic onlyThe theory focuses on a purely physicalist, neurobiological explanation of phenomenal experience and does not support any ultimate cosmic meaning or purpose.
Nature of mind
Ontology
Crick and Koch’s NCCReductive Physicalism/Materialism. The NCC approach is considered macroscopic materialism.
Recurrent Processing TheoryPhysicalism
Mind and body
Crick and Koch’s NCCIdentity Theory. Mental states are wholly identical to and fully explained by the physical NCC states.
Recurrent Processing TheoryIdentity/Reductionist approach, arguing that the notion of mind must move toward that of the brain, and consciousness is identical to a recurrent processing state in physical circuitry.
Fundamental or emergent
Crick and Koch’s NCCEmergent
Recurrent Processing TheoryEmergent
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.
Recurrent Processing TheoryQualia are generated when a certain recurrent processing state holds of the relevant visual circuitry, making the visual state conscious.
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.
Recurrent Processing TheoryRecurrent processing (feedback connections) in sensory and post-sensory areas (Stage 3) is considered sufficient for consciousness.
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).
Recurrent Processing TheoryLocalized in sensory and post-sensory areas, specifically recurrent activations in the 'back of the head'.
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.
Recurrent Processing TheoryConsciousness is the specific recurrent processing state itself. The underlying purpose is implied to move the understanding of mind toward the brain.
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.
Recurrent Processing TheoryEmpirically testable
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).
Recurrent Processing TheoryNot stated
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.
Recurrent Processing TheoryCritiques Global Workspace Theory (GWT) as being 'all about access but not about seeing'. Is itself criticized by Ned Block as a 'truncated form of the global workspace account'.
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)
Recurrent Processing Theory
- Towards a true neural stance on consciousness, Victor Lamme (2006)
- How neuroscience will change our view on consciousness, Victor Lamme (2010)
- Wu, 2018 (Discussing Lamme's RPT) (2018)