NEURO & COGNITIVE SCIENCE

Intro: One of the most notoriously difficult problems in science to crack is, rather ironically, the one that is closest to home. This is the challenge of understanding our own consciousness.

Put simply, understanding our own consciousness involves finding an answer to the apparently intractable question of how the chemical and neurological processes occurring within our bodies lead to the senses of perception and awareness with which we experience the world around us. Up until relatively recently, scientists as a whole were reluctant to engage with the subject of consciousness, preferring to leave it entirely to philosophers. The religions of the world and the ancient Greek philosophers were prepared to address the issue, but the first to consider what has become known as the mind-body problem in a modern philosophical sense was René Descartes in the first half of the seventeenth century. He argued that the mind was not a physical entity and that it was separated from the body, which he described as being like a machine that was controlled by the mind. Cartesian dualism, as this view is called, proved to be enormously influential and was one of the reasons why scientists were reluctant to get involved with the question, because, if the mind is non-physical, then it cannot be studied using empirical methods.

One way of overcoming the problem created by Cartesian dualism is to reject the idea that the mind and body are separate in the first place. This is known as monism and, in one form or another, is largely the position taken by most philosophers of the mind today, together with those scientists who are prepared to engage with the philosophical aspects of the study of consciousness. The way in which philosophers describe the concept of monism is a great deal more complicated and involved than is described here, but it at least provides a philosophical stance by which consciousness can be investigated, even if it does not actually advance that study very much on its own.

The Hard Problem

Over the past few decades, philosophers and scientists have begun to engage with each other more fully than in the past, in the realisation that moving the study of consciousness forward will most likely require input from both sides, and perhaps even an entirely new way of approaching the subject. In part, this involves specifying exactly which questions science is attempting to answer. One of the best-known examples of this has been provided by the Australian philosopher David Chalmers, who distinguishes between what he calls the easy problems and the hard problem of consciousness. The easy problems are those which can be addressed by science as it stands, and concern those processes occurring in the brain and central nervous system which can be detected and measured – or, at least, may well be in the not-too-distant future, as the technology to investigate such mechanisms advances. Examples include how memories are created, stored and retrieved, and how our brains deal with a situation in which we are required to make a decision. In both cases it is possible to monitor what is happening in the brain, but much more difficult to understand how these changes relate to the phenomenon of being conscious.

The hard problem is much the same as the mind-body problem, in that it involves explaining how the physical processes of the brain result in consciousness. According to Chalmers, it is distinct from the easy problems because it requires an explanation of a subjective experience that is unique to the individual having that experience. One way of thinking about it was articulated by the American philosopher Thomas Nagel, who posed the question, “What is it like to be a bat?” We have, of course, not the slightest idea of what it would be like – the point being that if were able to work out all the electrochemical processes going on in a bat’s brain, we might get to know a great deal more about bats than we do now. However, we would still have no idea what it is like to experience the world from a bat’s point of view.

Not all philosophers accept that the hard problem exists in the way Chalmers and Nagel suggest – among them Daniel Dennett, who argues that, as neuroscience increases our knowledge of how the brain works, we are gradually getting closer to understanding consciousness, even if there is a long way to go. This has been likened to a computer engineer assembling a computer from its constituent parts, so that once it is put together correctly and switched on, it will become apparent how the internal structure relates to the overall functioning of the computer. Needless to say, we are nowhere near understanding how all the functions of the brain work, but if this analogy proves to be accurate, then at least there is a possibility that we will be able to unravel one of the great mysteries of science at some point in the future.

Alternative Theories

At the University of Wisconsin-Madison, the Italian neuroscientist Giulio Tononi has been working on a theory of what consciousness actually is and how it can be measured. This is called the integrated information theory, which, rather than attempting to understand how the functioning of the brain leads to consciousness, takes the approach of starting with consciousness to identify its properties and, from there, working out what physical mechanisms are necessary to account for those properties. According to Tononi, two of the principal properties needed for a system to be conscious are that it receives information and that it integrates that information together into a unified whole.

Clearly there are more aspects to consciousness, but here we have the beginnings of a way in which it can be quantified and studied. This may ultimately lead to a full or much better understanding of what consciousness is.