Facing up to consciousness

consciousnessFacing Up to the Problem of Consciousness

David Chalmers

University of California Santa Cruz

Journal of Consciousness Studies, 2, No. 3, 1995, pp. 200-19


Chalmers seeks to distinguish the ‘hard problem’ of consciousness from all the other problems of neuroscience, which are termed ‘easy’ problems. He lists the easy problems as, discrimination and reaction to environmental stimuli, integration of information, reporting mental states, access to internal states, focus of attention, control of behaviour and the difference between wakefulness and sleep.

He says that all these problems look to be solvable in terms of computational and neural mechanisms. In several cases, we can expect to find mechanisms on a classical physical scale which brings together or retrieve information. Sleep/wakefulness could be solved by a description of the relevant neurophysiology. There is a clear idea as to the ways in which we might go about explaining them.

The hard problem of consciousness is the problem of experience, the subjective experience that accompanies the information processing. The something it is like to be a conscious organism. Chalmers prefers the terms ‘experience’ or ‘conscious experience’ to ‘qualia’ or ‘phenomenal consciousness’.

In general, Chalmers complains that there is a slipperyness to the treatment of consciousness by scientists and philosophers. Articles tend to start with their authors puzzling over the nature of subjectivity. Later in the article, the authors theory of consciousness is explained, and it is pronounced that there is no real problem after all. But on closer examination the article if found to have only tackled one of the ‘easy problems.’

The easy problems tend to involve functions of the brain and in principle any function can be explained by a mechanism, much as the function of heriditary information was explained by the mechanism of DNA. Even something more complex like the functioning of living organisms including humans could be explained in terms of the mechanisms for multiple functions such a reproduction, metabolism, response to the environment. Even seemingly immaterial aspects such as learning can be approached in this way by explaining the mechanisms by which information is absorbed and stored and how behaviour is altered in response to this. Reductive processes work in this way throughout the sciences.

However, the function/mechanism approach fails with consciousness. This goes beyond problems of how functions are performed. There is nothing about being a gene except transmitting information from one generation to the next, but there is more about conscious information processing in the brain than just processing information. It is a puzzle as to why all brain activity is not unconscious, as unconscious activity appears perfectly adequate to the task of processing and responding to.

Chalmers claims that a number of scientific attempts to get to grips with consciousness in the decade before his own book, in fact only tackled the easy problems. Thus Crick and Koch identified the so-called 40Hz oscillation as being correlated with activity in a number of parts of the brain that produce things we are conscious of. It was suggested that the oscillations bound the brain into a unity, and it was also suggested that they were correlates of consciousness. It was not suggested that they actually produced consciousness. Thus the theory does not contain an explanation for how consciousness is produced.

Chalmers takes the same view of Baar’s global workspace theory. Baars sees the contents of consciousness as a central processor coordinating a range of brain functions, and broadcasting what one specialist area may need to know about another specialist area. The theory is quite promising in terms of some aspects of cognition, and the differences between the conscious and the unconscious. However, it contains no explanation of why we have or need to have any experience of what is going on. The theory claims that consciousness arises because its information is accessible by the whole brain, but it produces no reason why whole brain activity should be any more conscious than other activity. Chalmers thinks that similar criticisms could be applied to all the other main theories of the period.

Chalmers feels that a number of approaches were adopted to get round consciousness. Some tackled ‘easy problems’ and some even suggested that consciousness might be beyond the reach of science. Another approach, of which Dennett has been the most notable exponent, was effectively consciousness denial. Some claimed that consciousness could not exist because it was not verifiable on an external basis, while others claimed it was the same thing as the ability to discriminate or report. Chalmers feels this is unsatisfactory given the central nature of conscious experience in our lives. With still other accounts, he complains of effective sleight of hand, when a functional account, suddenly has consciousness added at a later stage without apparent explanation.

Chalmers has more respect for theories that try to identify which parts or processes of the brain are related to consciousness. He considers this may be helpful, but stresses that any complete theory will need to go beyond this to explain why these particular components of the brain are conscious.

In looking for his own theory of consciousness, Chalmers takes experience as a fundamental. Most phenomena are explained by science in terms of lower level or simpler entities, but in physics there are a few fundamentals or given properties that are not explained, but which can be shown to relate to everything else in the world. As such, the theory is felt  likely to have more in common with physics and biology, because biology does not involve fundamental properties in the way that physics does.

Chalmers theory of consciousness relates to information, which he understands as information states embedded in information space. He suggests that some information has two basic aspects, a physical aspect and a phenomenal aspect. This is suggested as a basic principle that could explain the emergence of experience from physical matter, with experience arising as one aspect, while physical processing of information is another.

The reason for looking in this area mainly boils down to the role of the brain as a massive information processor and thus a likelihood that information and consciousness are related in some way. The chief problem with the theory, particularly when compared with some of the quantum theories of consciousness, is the lack of mechanism as to how the thing would work. Of course, any proposed mechanism would be even more speculative than the main theory itself, but at least it would allow people to test out the plausibility of their mechanism. The Penrose/Hameroff model has aroused much debate in this respect, because it does offer fairly detailed mechanisms. Although some of the resulting criticisms have been rather ill informed, they do at least test the robustness of the theory’s suggestions.

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