
Originally Posted by
DianeG
First off, I apologize if this post is long winded. It’s a topic I really enjoy.
As Dan pointed out, the definition of consciousness is problematic. Some philosophers and neuroscientists try to prune it down a bit by eliminating certain mental functions, like intelligence, memory, problem solving, learning, sensation - functions that computers are able to do - and restrict it to that rather hard to describe state of being aware and self-aware of ones existence in time, and experiencing qualia. Qualia, if you're not familiar with the term, is the subjective, private experience of things like the redness of an apple (as opposed to lightwaves of a particular wave length) the smell of baking bread, the softness of velvet, the sound of piano music, the experience of pain and suffering. It's not simple sensation but the active experience of perception and the meaning our brains generate from these things.
Qualia is important to philosophers, who debate endlessly about whether if your green was my red, would we be able to tell? Or could you ever effectively explain or communicate the experience of color to someone who never experienced it, even if you included every available bit of data about lightwaves and eyeballs and how color functions in nature and our response to it.
But qualia is also important to scientists as well, because it is linked in the brain to consciousness. Here's an example:
Some people with damage to the visual cortex of the brain and can see, without the conscious experience of seeing. They deny being able to see, but if asked to "guess" they can accurately identify objects and track movement of them. There are two visual pathways from the eyeballs to the higher centers of the brain. The evolutionarily older pathway, more prominent in some mammals and reptiles, goes to the brain stem, and then gets relayed eventually to the higher centers of the brain. The evolutionarily newer pathway goes from the eyeball through the thalamus to the visual cortex of the brain. In blindsight patients, the first pathway still works, and some kind of visual information is shared with other parts of the brain, but without the conscious experience of it. The second pathway, or part of the the visual cortex it leads to, doesn’t work, and the patient has no experience of the qulaia associated with vision. The patient really does feel as though he's just guessing or knows something without knowing how he knows it.
There are lots of different theories about qualia, that qualia makes things stand out, both physically and in a meaningful sense - red nutritious berries against a green leafy background, for example. Qualia may be the brain's symbolic language. Qualia also seems to be useful in helping our brains distinguish reality from non reality. The qualia of seeing an actual monkey is vivid and clear cut. It's also irrevocable - I can't decide "not to see" the monkey. The qualia of a monkey that I imagine in my minds eye is fleeting and fuzzy. It's also revoccable - I can get rid of him by thinking of something else, or I can dress him up in a suit and top hat in my mind. (The qualia of a monkey in my dreams is some where in between real and imagined monkeys.)
Without this difference in clarity of qualia, imagining that I am eating a delicious meal would be indistinguishable to my brain from actually eating a delicious meal, and I might starve. Qualia allows me to run virtual test simulations in my brain - to plan and remember - without confusing those simulations with reality.
But these are just hypotheses.
The second part of your question -the self - is also an important aspect of consciousness, to both philosophers and neuroscientists. Although the word "soul" doesn't have a scientific definition and has certain religious overtones, I don't find your reference to it silly. It does describe ones subjective experience of ones self, the individual "I-ness" and unified sense of self that exists in time, something humans have been trying to explain in various ways, probably ever since they became self-aware. It's a topic with a long religious and philosophical history, but it's important to neurologists and even computer scientists as well.
Some hard core materialists like Dennet suggest that consciousness is an illusion, and there is evidence for this position. (But if it is an illusion, it's a stubborn one!) Neuroscient Antonio Damasio says consciousness is generated when the brain maps self-object relationships and then re-maps the maps of self-object relationships, but his critics say that is just a fancy way of saying the brain thinks about thinking and it doesn't really get you anywhere.
In the brain, the structures most closely associated with consciousness (Reticular Activating system, the thalamus, the cingulate cortex and the somatosensory cortex) are the same ones associated with a core sense of self. Surprisingly, they are mid level brain structures, except for the somatosensory cortex. In older anatomy textbooks, they are described as just being like relay stations or switch boards, or controlling level of physiological alertness, but these areas seem to be getting more attention now.
A primitive form of self awareness seems to come with any ability to distinguish self from non-self, and ours may simply be more developed, allowing us to better navigate the world, form complex social relationships, analyze our own behavior and the positive or negative outcomes of our choices. In an excellent book called "I Am a Strange Loop," Douglas Hofstadter sees consciousness as what happens when an intelligent animal turns its analysis inward, kind of like what happens when a video camara is pointed at itself, or an amplifier amplifies the sounds picked up by a microphone placed to close to a speaker. He looks at other similar loops in in nature or mathmatics.
Some neuroscientists see the self as an illusion, as story the brain tells itself. They suggest that the brain is group of modules, running different programs, and competing for dominance. They argue that the“self” is which ever part of the brain presents the most convincing or loudest argument at the moment, and that there is no little “you” inside of your head making those decisions, and watching the world as if on a movie screen. There’s lots of good evidence for this view, including the experiments by Libet that Dan mentioned, as well as split-brain research by Gazziniga and others. Split brain patients do not have a connection between the left and right hemispheres and essentially have two “selves” that make different decisions and have different access to information and sensory input.
Personally, I think the sense of self evolved from more primitive systems that distinguish self from non-self, and is also tied to feedback loops that monitor intentions and the actual results, compares them, and makes corrections. Of course these kind of feedback loops work below the level of conscious awareness in the cerebellum of the brain, to coordinate physical motor movements, so maybe they don't absolutely require consciousness. But if an animal only became aware of its actions after the fact with no sense of "I am the one who is doing this", it would have to constantly reason backwards about whatever occurred.
Any way, if consciousness and the self are topics you are interested in, the Wikipedia article is not a bad place to start, and there are lots of cool books out there. Some ones I like in addition to Hofstadter are:
Who's In Charge? Free Will and the Science of the Brain by Michael Gazziniga
The Tell-Tale Brain by VS Ramachandran
Igcognito -The Secret Lives of the Brain by David Eagleman
Subliminal - How Your Unconscious Mind Rules Your Behaviorl by Leonard Mlodinow
One I haven't read yet but plan to get is "Self Comes to Mind" by Antonio Damasio. Daniel Dennet and Patricia Churchland also are big in consciousness and brain research.
Good Luck!