Consciousness: Mapping the Physical and Mental Universes

By Narayani Ganesh

If the manual of life is encoded in our DNA, where do we look to find the blueprint of consciousness? This was a subject that fascinated Francis Crick, who, along with James Watson, discovered the double-helix structure of DNA 50 years ago.

Engrossed in the mysterious relationship between mind and body, Crick later felt impelled to turn his attention from matter to mind and from biology to philosophy Ñ but he persisted in believing that one day, consciousness could be explained in biological terms, using the tools of neuroscience.

The human genome map reveals to us that we are made up of some 40,000-odd genes, each of which carries inherited information. So, say some, we are the sum of our genes. It seems, however, that we could well be that and more Ñ a combination of nature and nurture, matter and mind.

But what is the mind, besides the countless neuron cells that transmit nerve impulses through the complicated nervous system? And neurons are not confined to the brain Ñ their reach extends to even the stomach and intestines.

So Crick would often pose an intriguing question: - When you digest your lunch, is that you? Crick questioned the hypothesis that there was a line dividing the functioning of the body and mind Ñ he preferred to approach the question of consciousness through neurobiology.

Consciousness and awareness are essentially local phenomenon, generated by activated neurons, said Crick. He did concede, however, that with our present (limited) understanding of neural correlates, it would be impossible to prove it scientifically.

Crick also admitted that it would be difficult to explain to others the nature of any conscious experience, without talking about it in relation to other such experiences. But since consciousness is subjective, science alone Ñ which is objective Ñ cannot fully explain the inner life of the mind.

This is the information age, thanks to the giant leaps we have made in computer chip technology. David Chalmers, of the department of philosophy, University of Arizona, raises a complex futuristic question: If the precise interactions between our neurons could be duplicated with silicon chips, would it give rise to the same conscious experience? Can consciousness arise in a complex, synthetic system? In other words, can consciousness some day be achieved in machines?

- Consider a silicon-based system in which the chips are organised and function in the same way as the neurons in your brain. That is, each chip in the silicon system does exactly what its natural analogue does and is interconnected to surrounding elements in precisely the same way. Thus, the behaviour exhibited by the artificial system will be exactly the same as yours. The crucial question is: Will it be conscious in the same way that you are? - asks Prof Chalmers.

The synapse does not explain everything. Whether artificial intelligence can evolve to the extent of human consciousness or not, the fact remains that the many conflicting theories of the universe are not confined to the physical: We live in individual universes of the mind, too. If retraction or reversal of cosmological principles Ñ Stephen Hawking recently revised his theory of black holes Ñ are acceptable in the objective realm of science, so too should it be in the subjective mental universe.

If our perceptions of the subjective and objective universes are in a state of constant flux, it follows that theories of everything that seek to explain the A to Z in either domain will necessarily be in a state of constant evolution. And so we, too, will constantly be in search of an elusive truth...