MyKell

Sweep,
You just described LTP. What is your point??? You're totally missing my point!!!!!!! You're talking about a completely different hierarchial level. Got caught up in the language I guess, by what a code means. Was my description that vague... Gee!
Besides, selection in the brain does not only involve motor neurons (BTW you are referring to the spinal cord, not even the brain) for more information check Gerald Edelman's work.

excreationist,
I know what you are trying to say about categorizational memory. It's very different from what I was trying to say. Not being able to say if it's a cat or a dog does not mean that one does not remember the concept of a cat or a dog. It's probably some form of expressive aphasia or something. And again, we got lost somewhere on the hierarchial levels which I was very specific in the beginning. For a microthrombus to give clinical symptom of a stroke it does not affect single neurons, it affects neuronal circuits.

To gain more insight into selectional mechanisms check out the Mind/Brain Duality thread.

Cheers

excreationist

What if they see a cat and insist it is a dog (rather than complain about a lack of memory) - or see a duck and insist it is a bird? That's what I remember from the show.
I think it's a bit like me seeing a 2000 Harley Davidson FXSTD Softtail Deuce and saying it is a Harley Davidson - and being unable to do little more than describe its colours and shape. (I found out that name by looking on ebay). If I was that man, I could have previously had that memory but I would be unaware that I used to, and I'd think that all that I'd ever known about motorcycles like that was that they're "Harley Davidsons".

Probably because of my very limited knowledge about the brain.

Well I don't know enough about the topic to respond...

I'd probably have to study a lot about neuroscience and cognitive science to fully appreciate what is being said there. When I read things with my current knowledge I'm probably misinterpreting things.

sweep

now I'm really hooked and I want to know more.

What is non-representational memory? I don't understand. Please go into more depth.

If memory relies on synaptic strengthening why can't it be memory?

Retrieval of memory involves recategorization, you wrote. IF we repeat the retrieval process enough the memory trace is stronger, right. Doesn't that mean that the degenerative process is lessened?

Also when you talk of brain damage, and chunks of knowledge, you're referring to semantic memory, not episodic memory, right?
We only need to take in the most salient features of the world so it doesn't surprise me that memories for places are fainter. Even so, particularly meaningful events produce corticosteroids, including beta adrenaline, which are implicated in memory formation. So, when were excited, stronger memories are created, and more lasting.

Now I'm hoping you can relate to what I have put, and give me some feedback to tie in and hopefully we can both benefit.

cheers, mykell

m00ner

I wish I was smart so I could think like you guys are.

sweep

don't wish, will>> I will read some books. There again will is a matter of preference. Are you interested in Long Term Potentiation? Do you know what Habituation and Senstisation mean?

mykell, this was posted by you in the mind/body duality thread.

(To be honest a lot of it gave me a headache. I'm not sure what to make of Frotiw, but my impression was that it was a bit long winded and could have been condensed a bit more. Perhaps I don't know the subject matter as well. It is difficult for me to know whether to really concentrate on what someone is trying to get across. If the matter is drawn out and the substance little, I get pissed off, because I have wasted all my time thinking that this person was really on to something. Then again that might not be the case, and that is a separate issue)

so, the quote. I was talking about the cellular behaviour of the brain. What codes are you talking about? *see your response to my description of LTP* Which hierarchical level are you writing about?

also you told us to get more of an insight into the selectional processes of the brain, by looking at that thread, but I don't see much, if any. Perhaps you could elaborate, or at least paste the relevant text. Forgive me, if I have over/underlooked anything important.

I wrote, in my last post, regarding your question of qualia:

novelty; the strength* of a new stimuli, enable us to discriminate between various hues, shapes, experiences. This can be seen on a cellular level, or at least I see this. If your eye focuses on a colour and doesn't move, which It cannot, the perception, consciousness of that colour will fade due to habituation. Continual stimulation (unchanged), in terms of pleasure, leads to loss of sensation. do you see what I am getting at?

*"We have noted that successful adaptation and survival do not depend on exact copying of external and internal stimuli. Rather, our success as a species demands that our sensory systems accentuate, from among the many thing happening about us, the important changes of stimuli. Without selectivity we would suffer from an overload of information and would end up with a confusing picture of the world. In addition to minimising sensory overload, the suppression of some sensory inputs may reduce the metabolic expense of nervous system activities."

MyKell

Ok, let's go into more depth.
Regarding the brain as a selectional (by necessity degenarate) is an extrapolation from the field of immunity. Recall that when an antigen is presented to the body, there is a repertoir of almost 10^9 antibody molecules,different from one another, which are ready to encounter it. A few (depending on the antigen) antibodies are able to recognize the antigen, evoke an immune response, and thus neutralize the latter. An immunological memory, depends on "clonal selection" that happens to the B-lymphocytes producing those antibodies. They transform into plasma cells and can be reactivated much more readily when a second introduction of the antigen occurs.
Now, clearly, the immunological memory is "non-representational", there is no clear representation for say, Hepatitis B surface antigen is. The memory is stored as an ongoing process of B-lymphocyte maintainence, which is only reactivated in a further immune response--a process . The phenomenon also clearly shows how the system is degenerate (more than one antibody do the same job).
The brain is thought to be the same way. Neuronal circuits could be (roughly?) thought of as antibodies categorizing the ambiguous presentation of the world. As Francis Crick describes, It is a "winner-takes all mechanism". The neuronal circuit that happens to be better adapted to process the "information" at that time projects to the anterior areas of the brain and affects behavoir.
Hebbian Plasticity, LTP/LTD, is the molecular mechanism thought to contribute to neuronal circuit formation and subsequent strengthening and weakening... although it is not firmly established (even by the leading scientists of the field)... See, the correlation above!
Anyway, so I don't think that synapses are memories, because synapses are not the only places for information processing. Remember, neurons are not the only cells in the brian (most people don't even realize that!)
Also, to show that something is necessary does not indicate that it is sufficient, synapses have never been isolated and constituted memories, besides what synapses are you going to isolate and call a memory of a car. It's not a certain anatomical entity, remember, it's a non-representational recategorizational process.... the car is not the same everytime you remember it.
Now regarding Phenomenology that I was telling excreationist about. This is the whole purpose of discussing these things on Philosophy, otherwise, we can discuss them on Sci/Skept. We have absolutely no idea what questions to ask regarding the phenomenology of memory retrieval. What happens in your brain when you remember the color "red" and by what mechanism is that transformed into the "redness" you feel .
Again, the code is not the set of chemicals that constitute LTP. What was that about by the way, I still don't get it! I meant that the brain does not know what to expect from the world before actually encountering it. No brain language that is analogous to a computer language. Now I'm sure that you'll find people referring to some sort of "brain talk", but it is a totally different thing than what I'm talking about.

Mooner, you're probably smarter than all of us. Damn, at your age I had no idea what the hell all that meant.

Cheers

MyKell

Excreationist,
Sensory aphasia is a clinical condition occuring after an area of the brain called Wernick's area is damaged. You should probably compare the symptoms of patients with a Wernick's lesion with those that you saw on television. I really can't make a diagnosis with a scanty history and no physical examination... but that's just a guess from what you were telling me.

sweep

gotcha- non- representational. More probable of recognition even though no recognition is taking place.

In case you missed me:

I wrote, in my last post, regarding your question of qualia:


quote:
--------------------------------------------------------------------------------
We only need to take in the most salient features of the world so it doesn't surprise me that memories for places are fainter. Even so, particularly meaningful events produce corticosteroids, including beta adrenaline, which are implicated in memory formation. So, when were excited, stronger memories are created, and more lasting.
--------------------------------------------------------------------------------



novelty; the strength* of a new stimuli, enable us to discriminate between various hues, shapes, experiences. This can be seen on a cellular level, or at least I see this. If your eye focuses on a colour and doesn't move, which It cannot, the perception, consciousness of that colour will fade due to habituation. Continual stimulation (unchanged), in terms of pleasure, leads to loss of sensation. do you see what I am getting at?

*"We have noted that successful adaptation and survival do not depend on exact copying of external and internal stimuli. Rather, our success as a species demands that our sensory systems accentuate, from among the many thing happening about us, the important changes of stimuli. Without selectivity we would suffer from an overload of information and would end up with a confusing picture of the world. In addition to minimising sensory overload, the suppression of some sensory inputs may reduce the metabolic expense of nervous system activities."


alright, a silly thing to say: synapses aren't memories. That is like saying a sparkplug makes a car move.

the brain doesn't know what to expect from the world but it does have the tools to ready it for input. By our nature, we are ready to make sense of the world; we are not simply a blank tablet, nor is it safe to say that there is a 'ghost in the machine', without talking metaphysics and hocus pocus.

from what I understand, taking the example of a visual stimuli, I suggest there are the cortical structures that store the information, in a non-representational way, and feedback to the motor circuits, which relay the representational side of 'things'. Remember, we have ten times as many inputs from the visual cortex to the eyes, as there are from the eyes to the visual cortex. When we dream the input goes all the way to the eyes then back to the brain again, and is interpreted as real input. So the transformation I am relaying could be seen as feedback between the motor and the information sites.

MyKell

Did I say that?



I agree. But I do not see how that relates to anything we were discussing before. Are we discussing memory or consiousness? Concsiousness is highly differentiated yet highly integrated process. The lack of differentiation due to a non-changing stimulus causes the blindness you're talking about.



I do not think anyone is born as a tabula rasa. We begin categorizing the world in utero. Also, the body presents itself to the brain during development, so the fact that we have opposed thumbs affects our later categorizations of the world. But again, what are we discussing exactly?



That doesn't solve the qualia problem or how we feel the world. Anyway, I think you should read contemporary theories of visual consciousness. Crick/Koch theories are a good place to start. They had a recent review in Nature Reviews Neuroscience on Neural Correlates of Consciousness, check it out.

There multiple hierarchial levels in the brain, people usually misunderstand each other because often they talk about different hierarchial levels.

sweep

no, you did not say that, but from what I understood (not easy considering you assume prior knowledge on my part: 10^9 ???)..

non-representational: prior contact to a stimuli puts the receptive cell in a prepared state, as excreationist noted (weighted). This information doesn't say anything about the input only that it reacts to it as though some kind of recognition is taking place. As you put it: ' the immunological memory is "non-representational", there is no clear representation for say, Hepatitis B surface antigen is'. So, the information doesn't say anything about hepatitis B, but has had prior contact, which is all is necessary to deal with this phenomena.

back to the issue of qualia, why, if we have a brain that stores the information relevant to recreate impressions left upon our senses does that not at least point to the mechanism by which recreation occurs. If you're referring to the will: how do I will a memory, then I would suggest there is some part of the brain, (a minds eye) that comes across information as it happens. Only the timing will tell what comes up.

Unless you know something that I don't, please explain, otherwise I am going to continue to bleat the same process until you pose the problem in a way that leaves me without response.


anyway i will have a look at that source. How about a link, or maybe you could post it here?

thanks