A possible materialistic explanation of consciousness in slightly more detail (but still not enough!)
Consciousness, or subjective awareness, suffers from arguments over its ontology; just what is it? Dualistic, spiritual accounts and monistic, idealistic explanations have largely given way, in the modern scientific community, to various materialistic models whereby consciousness is understood as an emergent property of a highly complex system of neural connections and interactions. These theories naturally integrate biology and psychology, allowing progress in research methods of neuroscience to contribute to modern theories of mind. Theories of mind are important in providing a background of understanding upon which we can achieve useful knowledge through relevant and appropriate investigations. Within the psychological study of consciousness, philosophy retains an important level of contribution through identifying plausible theories and possible avenues of research.
Although the scientific approach is essentially materialistic and often criticised as being overly reductionist, the physical state of the brain is an important element in any explanation of consciousness. Changes in brain state are undeniably related to changes in mental state or experience (as psychotropic drug use can confirm). It is the nature of the relation which is in question. The so-called ‘hard problem’ (David Chalmers,1995) of consciousness concerns this relation; how do mental events arise from physical ones?
Extreme materialistic theories of mind are criticised for ignoring subjective experience; eliminating the ‘hard problem’ of consciousness. Many people understandably find this unsatisfactory and overly reductionist and favour theories which encompass both the physical and mental levels of explanation.
An early theory of consciousness associated types of neural activity with types of mental activity (Rose, 2006) and is known as type-type identity theory. Simply identifying mental states with brain states is problematic since similar mental states may arise from disparate brain states. Identity theory originated with the argument that there exists categories (types) of mental states (eg. experiencing pain) which are identical to (result from) categories (types) of neural activity (eg. the firing of particular ‘pain’ neurons). Fodor (1968) argues that species with wildly different physiology may still experience pain and so it is wrong to ascribe certain mental states exclusively to particular neural configurations.
Identity theory is also somewhat overly reductionist in that it explains consciousness solely in terms of the internal workings of the brain thus ignoring the wider environment. Consciousness is only ever consciousness of something; mental events only achieve meaning through correlation with the external world. Within type-type identity theory there is no difference between explanations of imagined and real events since explanation ends at the level of brain physiology. Further revision is needed to include context as well as content.
Functionalism allows for the situatedness of mental activity. Functionalist theories are concerned with understanding mental activity through investigating what that activity does; what its function is. This incorporates meaning through a contextual awareness of the contents of consciousness. There are various forms of functionalism including the cousin of type-type identity theory known as token-token identity theory. This is an account of mental events in terms of neural events analogous to the material used to make clothes; various types of material can be used to make the same item of clothing and various items of clothing can be made from the same type of material. Each particular item of clothing is made from a particular material and can be identified with it but isn’t restricted solely to it. Thus in token-token identity theory specific brain states are identified with (arise from) specific mental states but aren’t restricted solely to them; various physical processes may give rise to similar mental states and various mental states may arise from similar physical processes.
The problem of other minds concerns the fact that we cannot know the subjective experience of other people; my experience of red could be your experience of blue but we have both (arbitrarily) learned to call it ‘green’. If we call it the same thing and treat it the same way, in short, if the experience functions in the same manner, then it does not matter that we experience different things when we point to the grass and call it green. Token-token identity theory allows for both physical and mental differences; allowing that dogs may feel pain and that we simply cannot know what it is like to be a bat. As such it is an improvement on type-type identity theory.
There is much empirical evidence that the brain is functionally structured with various regions associated with various activity. Brain damage studies, neural stimulation and brain imaging techniques support the assertion that different areas of the brain perform different functions although these aren’t strictly delineated and higher or more complex processes may involve many interacting regions.
This modularity of brain function has caused a revision of earlier computational functionalism. Homuncular functionalism recognises the ‘nested hierarchies’ which are prevalent in nature. Organisation at the molecular level provides a structure with emergent properties which were not apparent at the molecular level but are apparent at the (several levels up) neural level. Organisation (interaction) at the neural level provides a structure with emergent properties, such as a pattern of activity, which is not possible at the level of a single neuron. Just as an arrangement of circles may create a structure with triangular properties and these triangles may be arranged to form a square, so too can we bridge the mind-body divide by identifying properties which emerge from various levels of organisation. This form of functionalism recognises the importance of the contribution of each level of explanation in providing the material for subsequent levels. As such it is an improvement on earlier computational functionalism which suggested that higher cognitive functions were rule bound (algorithmic), much like computer programs, and could therefore be implemented in any suitably organised medium; be they string telephones, silicon chips or the population of China (Blocks, 1978). Homuncular functionalism asserts that the properties of higher cognitive functions, as well as consciousness itself, emerge from the properties of the interactions of the components of various levels of organisation right down to the molecular and sub-atomic levels. It serves to provide a materialistic account of consciousness as an emergent property of the organisation of organic systems. This binds our conscious experience to the physical world as well as connecting it to the universe as a whole at higher levels of organisation, thus uniting physicality and spirituality in a continuum of complexity.
A further revision of functionalism attempts to include an explanation of why we are as we are. Teleological functionalism involves a recognition of the purpose of the functional elements which contribute to our conscious awareness such as our senses and our imaginative ability. This refinement of the functional explanation of consciousness includes an evolutionary perspective which explains the existence of various elements of being in terms of their fittedness within the changing environment through which we developed. It further emphasises the importance of context for both our physical and experiential selves. Teleological functionalism helps us to provide explanations of various levels of organic life in terms of what they are for. This may become problematic at the extreme limits of our knowledge; what is there that has a purpose to form quarks and what purpose does the universe serve? It is also debatable whether it is useful at the level of our lived world; are organisms for replication? Is consciousness for better serving that end? Perhaps so, but doesn’t it just feel more significant than that?
Block, N. (1978) Troubles with functionalism. In Savage, C.W., ed., Perception and Cognition: Issues in the Foundations of Pyschology. Minnesota Studies in the Philosophy of Science, Vol.9. University of Minnesota Press, Minneapolis, pp. 261-325 (as referenced in Rose, 2006)
Chalmers, D. (1995) Facing up to the Problem of Consciousness. Journal of Consciousness Studies 2: 200-219
Fodor, J. (1968) The appeal to tacit knowledge in psychological explanation. Journal of Philosophy 65, 627-640 (as referenced in Rose, 2006)
Rose,D. (2006). Consciousness: philosophical,psychological and neural theories. Oxford: Oxford University Press.
Blackmore, S., (2003) Consciousness, an Introduction. Hodder and Stoughton
Carter, R., (2002) Consciousness. Weidenfeld and Nicolson
Dennett, D.C. (2005). Sweet Dreams, Philosophical Obstacles to a Science of Consciousness. Cambridge, Massachusetts : MIT Press