Monday 5 September 2016

What is Consciousness?

From New Scientist August 2016

Metaphysics special: What is consciousness?

How does something as physical as the brain create something as immaterial as your sense of self? It could all just be one big trick of the mind


Metaphysics 2
Francoise Hillemad/plainpicture


In Cotard’s syndrome, the feeling of existence corrodes but something more fundamental does not (see “How do I know I exist“). Even though people with this rare condition feel they don’t exist, there is still an “I” experiencing that feeling. What is that “I”? One answer is that it may be a by-product of consciousness itself.


René Descartes was convinced that the body and conscious mind are two different substances: the first is made of matter, the latter is immaterial. His ideas influenced neuroscience until a few decades ago, but the field has moved on. Today, it is widely accepted that our brains give rise to consciousness.
But how? That is a raging debate. At its heart is what philosopher David Chalmers at New York University termed the “hard problem” of consciousness: how can physical networks of neurons produce experiences that appear to fall outside the material world? As Thomas Nagel, also at New York University, put it in the 1970s: you could know every detail of the physical workings of a bat’s brain, but still not know what it is like to be a bat.
“You may know beyond a doubt that you exist, but your ‘I’ could still be an illusion“
Broadly speaking, those trying to solve the hard problem fall into two camps, according to psychologist and philosopher Nicholas Humphrey. There are those who think that consciousness is something real and those who say it’s a mirage, and so dismiss the problem entirely.

Mind trickery

The former camp argues that consciousness is a fundamental component of the universe, one that exists alongside matter and has properties which, perhaps conveniently, cannot be explained by our present understanding of physics. If taken to the extreme, says Chalmers, this idea can lead to panpsychism, the view that all matter – even inanimate objects like rocks – is imbued with some degree of consciousness.
Even without tackling that particular Pandora’s box, this camp faces a daunting challenge. We know that conscious thought can influence the body. A conscious desire to move your arm results in physical movement. But the fundamentals of how this happens remain hazy.

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Those on the other side say the hard problem creates one where there is none. “It’s an unsolvable mystery, because the problem is ill posed,” says neuroscientist Michael Graziano of Princeton University. He argues that consciousness is nothing but a trick of the mind. What’s more, the brain doesn’t just create the illusion of consciousness but also the feeling that there is a separate, immaterial “I” having a conscious experience. In other words: there is no need to explain strange interactions between material and immaterial things because the immaterial things don’t really exist.


For Graziano, Tufts University philosopher Daniel Dennett and other “materialists”, the real issue is not solving the hard problem but explaining how the brain accomplishes this trickery. Graziano resolves this by saying that consciousness is “the brain’s way of describing to itself what it means to pay attention to and deeply process a signal”.
The argument goes like this: we must pay attention to our environment to survive. As a result, our brains have become very skilled at representing the world around us. Somewhere in the course of evolution, they began representing objects as having immaterial properties, and in so doing it generated the mirage of consciousness.
Ultimately, most materialists take the view that after we die and our brains and bodies have decomposed, there is nothing left. That must mean that our prevailing sense of a separate, immaterial “I” was also an illusion.
Which brings us back to the previous question: although you may know beyond doubt that you exist – and indeed it is very possible that you are not a simulation – the “I” you perceive yourself to be could still be an illusion.
This article appeared in print under the headline “What is consciousness?”