Oliver North
Junior Member
Originally posted by red g jacks
how well known are the mechanisms by which humans form, store & access the 'concepts' we associate with certain experiences?
jeez, set the bar a little higher, eh? 😛
the answer to that question depends on what you mean by "well" and which "concept" is in question. How well known are the mechanisms that give us the experience of "blue"? in some ways we know this down to a neuron-by-neuron level (it would be different for each person, but I mean this in terms of building a model of how things work). Something like, how well do we know where memory comes from? well, not as well, we can speak in broad terms about encoding and retrieval, we can point to clearly important neural structures and we have models that cover the issue very well, but there are still much more fundamental questions (for instance, while it is known that memories compete with eachother to become the "winner", ie, the thing we consciously remember, the exact mechanism is still unknown even though there are many models that talk about "gating" or lateral inhibition... I'll elaborate on that stuff if you are specifically interested).
I think what you want is a little bit above this though, isn't it? Like, you aren't talking about specific component pieces of consciousness, but the actual full conscious experience, no? And this is where it starts to get complex. Broken down, and imho (though, it would be the majority view in neuroscience), there is no real, single thing called "conscious experience". All of these individual systems seem to work in tandem to produce an experience that only feels united as a single thing, but is really not. Think of it sort of like this: The eye doesn't feed a continuous flow of information into the visual cortex, it feeds information at roughly ~25 "frames" per second. However, we experience a flow of visual information over time that is not broken down into smaller parts. That is because the way visual information is processed puts it into this united perceptual experience, but it is really based on unique discrete moments of visual information.
Human consciousness and awareness works in much the same way. This feeling we get of a whole united experience is really just a by-product of how our individual systems process information. The best evidence of this comes from when people have deficits in various systems, such as amnesia or blindness. The "united" experience is not altered, though the person displays very specific deficits in the injured systems. As far as all the research up to this point shows, there is no "consciousness system" responsible for uniting these individual systems, but rather, our conscious experience is produced by the simultaneous functioning of the individual systems.
The closest thing might be what is called the "narrator", located in the left hemisphere of the brain. It is thought to create a linguistic narrative of the world based on immediate sensory context and relevant stored memory or emotional content related to those sensory contexts. Basically, at any given moment, it is going "this is what I see, this is what I was planning to do, this is what I remember about where I am.... etc" and puts it into a story: "I am at school today because I have class every morning". What is amazing is how messed up and literally gibberish these narratives can become if you restrict the flow of information to the left hemisphere. It isn't right to call the narrator a "consciousness center" because it is possible to be "aware" of things the narrator does not include in its narrative, but in terms of what I think you are getting at, reproducing this in a computer might give you what you are looking for.
Originally posted by red g jacks
what i'm really wondering, but i don't expect you to answer this, is how can we replicate it in machines? not specifically but generally speaking, what would be necessary for a computer so that when it encounters the term 'computer' it not only has a group of written characteristics which it associates with this term, but actually attaches some meaning to these characteristics which at least roughly parallels our own conception of the terms and which the computer can understand?
So, humans have a area in their brain called the amygdala. It receives sensory information and, to be very general, analyzes it for emotional content. What this means is that, when you see, hear, touch... etc, something, that information goes to the amygdala where it communicates with stored memories about emotional reactions to previous stimuli. Basically, when you see something that looks like your mother, the amygdala adds the emotional part of that experience.
What is very interesting is that, if information can no longer get to the amygdala, people present extremely bizarre behaviours. so, in the above mentioned example, if you saw someone who looked like your mother, but that information could not get to the amygdala, you would be convinced, convinced, that this person was an imposter. This is because your narrator cannot access the emotional content and essentially goes "well, it looks like her, but I don't feel anything, therefore it can't be her, therefore it isn't". This condition can be so pervasive that sufferers have been known to murder a parent to try and prove that they were a robot (I know that sounds weird, but that conclusion actually makes logical sense given the type of stimuli input the individual had; they know it isn't their parent, therefore how do you explain it? robot, clone, imposter... and then when it looks like they've fooled everyone else, or people tell you that you are crazy... etc - the narrative builds from there).
So, information flowing into the amygdala can be restricted selectively, meaning that audio information from the ears can still reach it, but visual information cannot (or vice versa). In this situation, a person could not recognize their parent by sight (and because we are visually dominant, even if they spoke), but if the parent called them from a different room, they would recognize the voice (the audio information still getting to the amygdala), and that context would allow them to then recognize the parent if they entered the room, because that "emotional context" carries over and informs the narrator.
another thing to keep in mind is that brains and computers serve fundamentally different purposes and were designed for totally different reasons. the brain evolved to act in the wild, and we still have structures as ancient as the brain itself buried deep within our lobes. Our emotional systems, our perceptual systems, our narrator, these all evolved not to be "self-aware" or whatever, but to facilitate our action in an environment, self-awareness being a by-product that itself might play a beneficial role in survival. Computers aren't designed to mimic this process, they are massive number crunchers. In fact, unless we dramatically change how cpu's work at a physical level, self-awarenes will be an issue of software, not of the computer itself. The software might be aware that it is a computer (because it simulates human neurology) but the RAM and such will still just be crunching 1s and 0s.