Online research in philosophy

This paper discusses recent neuroscientific research that indicates a solution for what we label the ''causal problem'' of pain qualia, the problem of how the brain generates pain qualia. In particular, the data suggest that pain qualia naturally supervene on activity in a specific brain region: the anterior cingulate cortex (ACC). The first section of this paper discusses several philosophical concerns regarding the nature of pain qualia. The second section overviews the current state of knowledge regarding the neuroanatomy and physiology of pain processing. The third section highlights the recent research by Rainville et al. [(1997) Pain affect encoded in human anterior cingulate but not somatosensory cortex, Science, 277, 968-971], which suggests that pain affect is encoded in the ACC. The final section of the paper spells out exactly how these data affect the causal problem of pain qualia.

The functionalist view of the nature of the mind is now widely accepted. Like behaviorism and physicalism, functionalism seeks to answer the question "What are mental states?" I shall be concerned with identity thesis formulations of functionalism. They say, for example, that pain is a functional state, just as identity thesis formulations of physicalism say that pain is a physical state.

This paper investigates the status of the purported explanatory gap between pain phenomena and natural science, when the “gap” is thought to exist due to the special properties of experience designated by “qualia” or “the pain quale” in the case of pain experiences. The paper questions the existence of such a property in the case of pain by: (1) looking at the history of the conception of pain; (2) raising questions from empirical research and theory in the psychology of pain; (3) considering evidence from the neurophysiological systems of pain; (4) investigating the possible biological role or roles of pain; and (5) considering methodological questions of the comparable status of the results of the sciences of pain in contrast to certain intuitions underpinning “the explanatory gap” in the case of pain. Skepticism concerning the crucial underlying intuitions seems justified by these considerations.

Functionalism cannot accommodate the possibility of mad pain—pain whose causes and effects diverge from those of the pain causal role. This is because what it is to be in pain according to functionalism is simply to be in a state that occupies the pain role. And the identity theory cannot accommodate the possibility of Martian pain—pain whose physical realization is foot-cavity inflation rather than C-fibre activation (or whatever physiological state occupies the pain-role in normal humans). After all, what it is to be in pain according to the identity theory is to be in whatever state that occupies the pain role for us.