Neural Correlates of Consciousness Meet the Theory of Identity

Abstract

One of the greatest challenges of consciousness research is to understand the relationship between consciousness and its implementing substrate. Current research into the neural correlates of consciousness regards the biological brain as being this substrate, but largely fails to clarify the nature of the brain-consciousness connection. A popular approach within this research is to construe brain-consciousness correlations in causal terms: the neural correlates of consciousness are the causes of states of consciousness. After introducing the notion of the neural correlate of consciousness, we argue (see Against Causal Accounts of NCCs) that this causal strategy is misguided. It implicitly involves an undesirable dualism of matter and mind and should thus be avoided. A non-causal account of the brain-mind correlations is to be preferred. We favor the theory of the identity of mind and brain, according to which states of phenomenal consciousness are identical with their neural correlates. Research into the neural correlates of consciousness and the theory of identity (in the philosophy of mind) are two major research paradigms that hitherto have had very little mutual contact. We aim to demonstrate that they can enrich each other. This is the task of the third part of the paper in which we show that the identity theory must work with a suitably defined concept of type. Surprisingly, neither philosophers nor neuroscientists have taken much care in defining this central concept; more often than not, the term is used only implicitly and vaguely. We attempt to open a debate on this subject and remedy this unhappy state of affairs, proposing a tentative hierarchical classification of phenomenal and neurophysiological types, spanning multiple levels of varying degrees of generality. The fourth part of the paper compares the theory of identity with other prominent conceptions of the mind-body connection. We conclude by stressing that scientists working on consciousness should engage more with metaphysical issues concerning the relation of brain processes and states of consciousness. Without this, the ultimate goals of consciousness research can hardly be fulfilled.

A First Principles Approach to Subjective Experience

“…Our approach begins with the basic principle that subjective experience is dependent on neural processing involving the execution of specific functions rather than merely being a result of the firing of neurons. For example, others have argued that neural firing of C-type peripheral sensory neurons just is pain ( Putnam, 1960 )—an idea that has strongly influenced philosophical mind-brain debates ( Puccetti, 1977 ; Levin, 2005 ; Montero and Brown, 2018 ; Polák and Marvan, 2018 ; Van den Hombergh, 2020 ). Rather than being pain, C-type firing may be just background noise without eliciting sensation ( Schäfers and Cain, 2004 ; Ermentrout et al, 2008 ).…”

“…Aside from lacking mechanistic explanatory power, such claims of type-type identity are focussed at the wrong level of abstraction just as claiming that water is an oxide would be. A more promising view is that subjective consciousness is not neural activity per se but rather a specific type of neural process ( Place, 1956 ; Smart, 1959 ; Polger, 2011 ; Polák and Marvan, 2018 ). How, though, could a neural process be the same thing as a subjective experience?…”

Free Will as a Paradox: Empirical Evaluation of the Construct of Everyday Consciousness

“…We should note that there are signs that natural scientists implicitly recognize their basic methodological error. Firstly, interpretations are gradually becoming more cautious and less unambiguous; for example, instead of "neural localization, " the term "neural correlate" is now used (Polák, & Marvan, 2018;Koch, Massimini, Boly, & Tononi, 2016). Secondly, in improving their experiments, supporters of the natural science paradigm have begun to provide subjects with more and more freedom, bringing laboratory conditions closer to natural ones (Perez, Mukamel, Tankus, Rosenblatt, Yeshurun, & Fried, 2015).…”

Evolving Consciousness: Insights From Turing, and the Shaping of Experience

“…In practical terms, what I am seeking is a guide to how NCCs might be identified, given that there is a reasonable prospect of eventually obtaining essentially complete datasets on the neural circuitry and functional properties of brain tissue from model organisms ranging from flies to vertebrates (e.g., Marques et al, 2019 ; Yu et al, 2019 ). As to controversies regarding how NCCs are best defined (Chalmers, 2000 ; Fink, 2016 ), or what their role as causative agents may be (Hohwy and Bayne, 2015 ; Polak and Marvan, 2018 ), the key point is that for hypothetical NCCs, as here, a degree of causality stronger than simple correlation can be assumed if we single out those NCCs or ensembles of NCCs that together are the proximate cause (Polak and Marvan’s regular cause) that a particular experience is evoked as opposed to any other experience. This assists the construction of thought experiments framed in topological terms (as below, in the section “The Turing Mechanism, part 2”), where the mapping is assumed between the physical realm of neural structure and function and an abstract experience space consisting of all possible experiences.…”