Neuroscience and the correlates of consciousness

Abstract

Can the brain tell us everything we need to know about consciousness? Some materialists say yes, while theorists of ‘extended mind’ and ‘embodied cognition’ criticise ‘neurocentrism’ and say no. Mysterians claim that we can never understand consciousness at all. This chapter briefly reviews the anatomy and function of the human nervous system, from spinal cord to neocortex. In searching for the ‘neural correlates of consciousness’ (NCCs), researchers hope to find those brain areas, networks, or processes that give rise to consciousness as opposed to those that do not – remembering that a correlation does not necessarily imply causation and that there may not be a ‘magic difference’ between conscious and unconscious brain processes. The differences between P-consciousness and A-consciousness, and between the correlates of ‘consciousness itself’ and its contents, are discussed. Classic experiments with binocular rivalry in both monkeys and humans are reviewed, exploring the idea of processes ‘competing for consciousness’. A different approach is to study brain activity in states of reduced consciousness, including ‘locked-in syndrome’, ‘persistent vegetative state’, and coma, as well as the effects of anaesthesia. The known neural correlates of pain forcefully expose the problem: why should the firing of certain groups of neurons actually hurt?