Brain to Z: C is for Consciousness

Time for more Brain to Z, this time looking at 'consciousness.'

Put simply, to each and every one of us, consciousness is everything. It’s our sensory experience: sights, sounds, and smells. It’s a sense of our body and feelings of pain, and pleasure. It’s our emotions and our memories.

By looking at the activity of the 86 billion neurons inside the human brain, neuroscientists have been able to draw correlations between bits of brain activity and given conscious states: the process by which decay in your molar leads to a feeling of toothache, for example, can be objectively observed and mapped out using brain imaging.

But for many researchers, just knowing that certain brain areas go along with certain aspects of consciousness doesn’t explain why physical processing in our brain should lead to any feeling at all. This has been dubbed, by influential philosopher and scientist David Chalmers, the ‘hard problem of consciousness,’ and something researchers are beginning to develop interesting new theories for.

The reductionist, brain based theory of consciousness argues against the existence of the so-called ‘hard problem’ altogether; that the concept of subjective experience is unscientific and, ultimately, illusory. Such theorists posit that consciousness is a property of physical matter, the functions and behaviours of which may one day come to be understood in terms of the fundamental laws which we understand to govern the universe.

Others believe, much like at previous points in the history of science, instead of working within the current limitations imposed on what we understand, we need to introduce new fundamental laws in order to incorporate room for consciousness. Just as James Clerk Maxwell could not see a complete explanation for electromagnetic phenomena within the confines of Isaac Newton’s laws of motion, so he presented electrical charge in what came to be known as the second great unification in physics.

One radical, ancient, and now revived theory of consciousness is that of ‘panpsychism;’ the idea that everything has a degree of consciousness; from the intense information processing of the human brain, to less complex processing in animals, to primitive precursors to consciousness present in the simplest parts of matter.

In this vein, in 2004, Guilio Tononi proposed integrated information theory, a theoretical framework which posits that consciousness arises from the integration of information within a system, rather than from the individual components themselves. IIT describes a mathematical model which quantifies the level of integrated information in a system, whereby a system with a high “phi” value is considered to have a high level of consciousness, like us humans. Critics have pointed out the challenges in applying the theory to empirical data and defining its terms precisely, while others have recognised it as a promising approach.

Controversial as it is, Tononi’s is but one theory from a flurry of activity in this field of cognitive neuroscience as the search for a fundamental explanation of consciousness goes on. While the challenges involved in studying this topic are great, so too is the potential prize. Understanding consciousness would be a key breakthrough in our understanding of ourselves and the universe.