You might be interested in the short thread launched in Dec. 2009 by 2bsirius, called "Neurotrash or Consciousness Unexplained". For convenience, I'll re-post here some of the key discussions.
A quote from Bertrand Russell, posted by participant boriqa:
Betrand Russell wrote in his short essay "Do We Survive Death?" (found in Why I am Not a Christian but first published in a book entitled The Mysteries of Life and Death, 1936):
Quote:
"Our memories and habits are bound up with the structure of the brain, in much the same way in which a river is connected with the rived-bed. The water in the river is always changing, but it keeps to the same course because previous events have worn a channel. In like manner, previous events have worn a channel in the brain, and our thoughts flow along this channel. This is the cause of memory and mental habits. But the brain, as a structure, is dissolved at death , and memory therefore may be expected to be also dissolved. There is no more reason to think otherwise than to expect a river to persist in its old course after an earthquake has raised a mountain where a valley used to be."
Here is my reaction to what Russell said, which takes his statement as revealing a practical, down-to-earth view of what consciousness might be, and whether it can exist separate from our bodies or brains:
The quote from B. Russell is persuasive. The experiences I have in life build my memory, which can be viewed as neural-electrical-chemical patterns stored in my brain and which are part of my awareness, along with my surroundings. I experience myself day after day in my surroundings, and this creates my memory, which can be viewed as my very identity as perceived by me. I can think about my remembered experiences (another natural brain function) and refine or even revise my memory/identity. And my identity may change as I continue to live and experience myself in my surroundings. Of course, other people who see, remember, or record aspects my life also build their own idea of what my identity is, which may disagree with mine in many areas.
A severe blow to the head or other physical event that damages or shakes up my brain tissue can damage memory, hence cause me to loose part of my sense of who I am. If my identity were not part of my body (i.e. if I had a "soul"), why should a physical event like a blow to my head affect my ability to know myself? To find out again who I might be, I would have to study records or ask other people what are their memories of me, in order to regain awareness of who I am. If my own former memory doesn't come back (i.e. if the brain damage is not repaired - maybe it never can be perfectly repaired), then the idea I have of my own identity will never be what it was. Again, this seems to contradict the idea of "spirit" or "soul", which, one would like to assume, is indestructible, or at least not affected by events which apparently should only affect brain tissue.
It appears to me, then, that my "consciousness" is just self-awareness as I and my brain perceive the world and build memories. If the brain is damaged, I can loose consciousness literally (get knocked out), or I can wake up - meaning my brain starts perceiving and remembering again - but still not remember my past experiences -- amnesia. If the brain heals sufficiently, some of that past identity may return. I may still know how to ride a bike, assuming that parts of my nervous system outside of my skull are not damaged, but even "muscle memory" depends on healthy nerve tissue.
Here is the challenging question: Where or what is the entity that does not depend on the body and the material of the brain, which some say is our "consciousness", and which thus should be able to survive nerve or brain injury, or even death?