@reiver

Consciousness And The Brain Stem

[H]ere's how it looks. [...] There is the brain stem in between the cerebral cortex and the spinal cord. And it is within that region that I'm going to highlight now that we have this housing of all the life-regulation devices of the body.

This is so specific that, for example, if you look at the part that is covered in red in the upper part of the brain stem, if you damage that as a result of a stroke, for example, what you get is coma or vegetative state, which is a state, of course, in which your mind disappears, your consciousness disappears. What happens then actually is that you lose the grounding of the self, you have no longer access to any feeling of your own existence, and, in fact, there can be images going on, being formed in the cerebral cortex, except you don't know they're there. You have, in effect, lost consciousness when you have damage to that red section of the brain stem.

But if you consider the green part of the brain stem, nothing like that happens. It is that specific. So in that green component of the brain stem, if you damage it, and often it happens, what you get is complete paralysis, but your conscious mind is maintained. You feel, you know, you have a fully conscious mind that you can report very indirectly. This is a horrific condition. You don't want to see it. And people are, in fact, imprisoned within their own bodies, but they do have a mind.

-- António Damásio

from "Antonio Damasio: The quest to understand consciousness"

Quoted on Sun Jan 15th, 2012