Polák, M., & Marvan, T. (2018) Neural Correlates of consciousness meet the theory of identity. Frontiers in Psychology, 9, 1269. doi:10.3389/fpsyg.2018.01269 www.frontiersin.org/article/10.3389/fpsyg.2018.01269
[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.
[Citing Place (1956)]  [Citing Place (1988a)]  
Citing Place (1956) in context (citations start with an asterisk *):
* The theory of the identity of mind and body, formulated more than half a century ago by Place (1956) and Smart (1959), gives a straightforward answer [to the question 'what kind of a metaphysical relation holds between brain processes and subjectively experienced states, such that they reliably co-occur?']: according to this theory, states of consciousness are brain processes and because of that, they systematically correlate with these processes. Thus, for example, a feeling of pain in my hip is identical to an activation of some area (or areas) in my brain, and this explains their regular correlation. In Smart’s version, the theory was a materialist attempt to discredit dualist accounts of mind-brain correlation, according to which the correlation is based upon a regular interaction between corporeal and incorporeal processes. The theory was formulated before the heyday of the modern science of consciousness and the brain imaging technology it employs. However, we believe that even today the theory can be used to sufficiently clarify the relation between brain and consciousness. It is a simple, elegant tool for interpreting the results of neuroscientists’ labbased mind-brain correlation measurements. There are other prominent metaphysical accounts of the brain/consciousness relationship. In this paper we shall show the advantages the theory of identity holds over those alternative accounts. Our second goal is to propose a working definition of a phenomenal and a neurophysiological type. Measurements of the neural correlates of consciousness focus on particular instances of mindbrain correlations, the relata of which are individual phenomenal and neurophysiological “tokens.” However, the obvious goal of this enterprise is to generalize the token measurements into systematic type–type mind-brain correlations. Still, the notion of a phenomenal and a neurophysiological type remains far from clear.
* A solution to the vertical mind-body-relation problem, though, need not inevitably appeal to types. The so-called weak (or “token-token”) theory of identity postulates identity only at the level of individual tokens of mental and neural events. However, as the advocates of the weak theory of identity (such as Davidson, 1970/2012; Fodor, 1974) admit, the token-token theory of identity does not permit systematization into law-like psycho-physical generalizations: individual instances of mental and neural events cannot be regimented into correlated type-sets. The stronger, type-type theory of identity identifies types of conscious mental states with types of brain states and thus allows for systematic psycho-physical type-generalizations. Various forms of this stronger identity theory have been offered over the years (Place, 1956, 1988; Feigl, 1958; Smart, 1959; Lewis, 1966; Armstrong, 1968; Bechtel and Mundale, 1999; Polger, 2011; Polger and Shapiro, 2016; see also Gozzano and Hill, 2012). Debates within the philosophy of mind are quite extensive as regards the facets of the identity theory, its pros and cons (see Polger, 2009, for an overview), but very little attention has been given to the pivotal question of what the neurophysiological and phenomenal kinds are. Most theorists participating in these debates use the notions of phenomenal and neurophysiological types only intuitively, without giving any explicit principles of individuation. The same can be said of the empirical scientists of consciousness.
* The theory of identity can be taken to be a form of inference to the best explanation – as some of its advocates, including Place, suggest. We cannot take the systematic mindbrain correlations to be a direct proof of the theory of identity, but we can hold that the theory of identity best explains them. The theory of identity, though, is not the only non-causal vertical metaphysical relation between the states of consciousness and brain processes. The literature distinguishes a number of such relations; each of them can claim to be the best explanation of regular mind-brain correlations. When compared to the notion of identity, these alternative materialist accounts work with the less reductive notions such as constitution, multiple realization and supervenience. These are all broadly naturalist: they all want to find a place for the phenomenal mind within and not beyond the physical world. Bennett (2011) puts them all in the general category of “building relations.” She shows that they are conceptually intertwined and also that there is a lot of room for disagreement as to the cogent characterization of any of these notions. We do not believe any of these relations to be superior to identity as a vertical mind-body relation. However, there is no space here to consider all these relations in detail. We shall only briefly indicate why we prefer the relation of identity over these less reductive notions.
Citing Place (1988a) in context (citations start with an asterisk *):
See also the citations in context of Place (1956)
* The psychologist Ullin T. Place, founder of the modern brain-mind identity theory, saw the theory as a means of overcoming the philosophical obstacles of the empirical study of consciousness (Place, 1988, p. 211). By observing the current research, one might come to conclusion that these obstacles are a thing of the past: consciousness research is blooming and empirical researchers do not bother much with philosophical conundrums about mind-body relations. However, perhaps they should care about them rather more. Overgaard (2017), recounting the challenges of future consciousness research, points out that one of these challenges will be to reintegrate the metaphysical issue of the mind-body problem into the scientific work, because arguably the whole of consciousness research is about the mind-body problem, i.e., about how exactly it happens that the states of the brain carry the subjective states of phenomenal consciousness. As Overgaard points out, and as we stressed in the preceding section, “it seems not to be the case that evidence that perceptual experience is associated with — say — activity in primary visual cortex also provides evidence to determine whether consciousness should be seen as — say — identical to or metaphysically different from brain activity” (Overgaard, 2017, p. 3). We will need, Overgaard adds, something “extra” to cope with this challenge.