Paper Review #2: An integrative, multiscale view on neural theories of consciousness
https://doi.org/10.1016/j.neuron.2024.02.004
The paper discusses a multiscale view on neural theories of consciousness, and ultimately ends the paper by concluding that the integration of apparently contradictory theories will actually provide a richer and more explanatory synthesis going forward. Moreover, the paper concludes that the differences capitalized upon in varying theories can be understood not as differences of fact but rather differences in philosophical, intuitive, and imaginative approach. More specifically, the various views are discussed at length, with each view being broken down into its primary constructs. Among the views discussed were recurrent processing theory, integrative information theory, dendritic integration theory, global neural workshop theory, among a few others. The paper speaks about cortico-thalamic connections at length, and makes special note of the necessity of integration between feedforward and feedback systems to create consciousness. Complexity and integration are among two concepts which are marked as highly notable.
Commentary: The Needle and the Pin
Of interest, the paper inadvertently highlights the limitations of each theory of consciousness by merely approaching the topic at all. This to say, each theory proposes its own limitations via its theory. For example, GNWT identifies consciousness as emerging through ‘access’, while IIT identifies consciousness as emerging through raw experience, or the phenomenological. For my purposes, the definitional differences of consciousness plainly illustrate the central issue present in the search for neural correlates of consciousness; that is, in the definition of consciousness. It is as though a group set about a hill to find a hidden needle that half of them pictured as a pin. It’s only fair that descriptions of the item of pursuit would differ if expectations were not common across the board.
In this case, we may define the accessing of consciousness as illustrated in GNWT as ‘contraction’ or ‘compounding’—the result of consciousness’s focus upon itself. This is the mechanism of consciousness which leads people to reify consciousness perception of itself into a separate ‘ego’. On the other hand, IIT’s definition of consciousness as what already exists before access or perception illustrates an expanding or ‘uncompounding’ of consciousness. This is to say, consciousness exists before it views itself. This accords with the Buddhist notion of ‘no-self’ or “anatta”. The differences in output from the same mechanism of consciousness leads researchers and contemplatives alike to change their definitions of consciousness based on a number of unknown variables. Of interest, the variance in the mechanistic output of consciousness further complicates the task of locating neural correlates of consciousness.
Contraction/compounding (GNWT): tighter selection, increased gain/precision (of predictions?) on one model or message, stabilization into a globally writable format. Characterized by: focus; stable, communicable content, etc. As an example, we may posit speaking to a person in a conversation on a certain topic.
Expansion/uncompounding (IIT): very broad, richly differentiated, less report-bound experiential field; high intrinsic complexity with less forced discretization into action schemas. Characterized by: openness, richness of background, dream-like or meditative spaciousness. As an example, we may figure the psychedelic state, where everything is ‘falling apart’ and ‘decompounding’ into less rigid fragments.
At any rate, the needle and the pin are revealed to be two sides to the same object. While RPT, DIT, and thalamo-cortical dynamics reveal functioning, IIT appears to give explanation to the “why” of structure, and GNWT appears to explain when experience within that structure is usable or accessible.