Tuesday, January 30, 2007

On consciousness

Thanks to ALD again for yet another interesting contact...

How often have we read - or at least tried to read - those obscure and convoluted tracts upon the evolution of morality, and the relationships between morality, self and god?

Steven Pinker, writing in Time, ponders "The Mystery of Consciousness".
The young women had survived the car crash, after a fashion. In the five months since parts of her brain had been crushed, she could open her eyes but didn't respond to sights, sounds or jabs. In the jargon of neurology, she was judged to be in a persistent vegetative state. In crueler everyday language, she was a vegetable.

So picture the astonishment of British and Belgian scientists as they scanned her brain using a kind of MRI that detects blood flow to active parts of the brain. When they recited sentences, the parts involved in language lit up. When they asked her to imagine visiting the rooms of her house, the parts involved in navigating space and recognizing places ramped up. And when they asked her to imagine playing tennis, the regions that trigger motion joined in. Indeed, her scans were barely different from those of healthy volunteers. The woman, it appears, had glimmerings of consciousness.

Try to comprehend what it is like to be that woman. Do you appreciate the words and caresses of your distraught family while racked with frustration at your inability to reassure them that they are getting through? Or do you drift in a haze, springing to life with a concrete thought when a voice prods you, only to slip back into blankness? If we could experience this existence, would we prefer it to death? And if these questions have answers, would they change our policies toward unresponsive patients--making the Terri Schiavo case look like child's play?

Some while back I put down my own thoughts in a similar vein...
How can I have such an attitude to life, and more particularly to death? By simple co-incidence one reason was brought home to me just in the past few days. Our Saturday paper featured the start of “Epilepsy Week” with an article on well known Aucklanders who have this condition. It is an article which I read with particular interest, and I was surprised to find (was I?) a reflection by at least two others of the same idea.

In my teens, I had gran mal seizures over the period from puberty through to about age 19. The point in common from those people in the article I mention, to my own experience is the sudden, in my case immediate, shift from “being” to “not being”.

There is no half way house. There is no “tunnel of light”. There is “being”, then there is “nothing”. There is no consciousness of the “nothing”. The only “memory” of the “nothing” comes with the return to consciousness. That, I regret, is about as plainly as I can express it. It is not “imaginable”. To give an idea of how hard this is;

Think of sitting in a very dark room. Now, turn on the light. Can you describe “no light”? Remember that you have experienced “no light”. If you had not had that direct conscious experience, how much more difficult would it have been to describe “no light”. That momentary confusion when the light is turned on; the contrast between “light” and “no light”; holds a key to the experience of waking from a gran mal seizure.

As a more direct parallel, see if you can describe “what it was like before you were born”? Certainly I know that I can not, without direct reference to this idea of “being” and “not being”, and without the benefit of conscious knowledge...

As an aside here, Pinker further on in his article makes an identical contention, that " when the physiological activity of the brain ceases, as far as anyone can tell the person's consciousness goes out of existence... near death experiences are not the eyewitness reports of a soul parting company from the body but symptoms of oxygen starvation in the eyes and brain."

Pinker puts it this way -
WHAT REMAINS IS NOT ONE PROBLEM ABOUT CONSCIOUSNESS BUT two, which the philosopher David Chalmers has dubbed the Easy Problem and the Hard Problem. Calling the first one easy is an in-joke: it is easy in the sense that curing cancer or sending someone to Mars is easy. That is, scientists more or less know what to look for, and with enough brainpower and funding, they would probably crack it in this century.

What exactly is the Easy Problem? It's the one that Freud made famous, the difference between conscious and unconscious thoughts. Some kinds of information in the brain--such as the surfaces in front of you, your daydreams, your plans for the day, your pleasures and peeves--are conscious. You can ponder them, discuss them and let them guide your behavior. Other kinds, like the control of your heart rate, the rules that order the words as you speak and the sequence of muscle contractions that allow you to hold a pencil, are unconscious. They must be in the brain somewhere because you couldn't walk and talk and see without them, but they are sealed off from your planning and reasoning circuits, and you can't say a thing about them.

On that latter point, there was a brief item I heard on the radio in the past couple weeks to the effect that the unconscious circuits of the brain actually begin operating "a measureable period" before the conscious decision to move. So, the act of moving a hand begins BEFORE the decision to move is consciously commenced. It is (as I heard it) almost a matter of "My hand is going to move" rather than "I am going to move my hand".

There is also the (documented) examples of people with the ability to influence, if not directly control some unconscious physical processes - specifically heart and breathing. First to mind are those who train and participate in "free diving" competitions.

Pinker continues...
The Easy Problem, then, is to distinguish conscious from unconscious mental computation, identify its correlates in the brain and explain why it evolved.

The Hard Problem, on the other hand, is why it feels like something to have a conscious process going on in one's head--why there is first-person, subjective experience.

- To Be Continued -

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