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Memory, what is it?

  1. Sep 2, 2007 #1
    This is a honest question that I hope someone can help me with. I hear there are cells that store memory and what not, but when I think of a cell, how does information with image and sensations get stored into something of that concept? If they know how, it would interest me to learn due to trying to understand where physical world and astral for example might coexist or collide.
     
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  3. Sep 2, 2007 #2

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    Howdy!
    1. For starters, this is a better question for the Mind and Brain Sciences section, so I am moving it there.

    2. Even though you've been posting in the philosophy forums on this site, please bear in mind that this is still a science-based group of forums, and you probably won't get much response to inquiries that involve speculative and untestable ideas like "astral" worlds.
     
  4. Sep 2, 2007 #3

    DaveC426913

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    It is believed that images and memories are stored in the countless intricate connections between countless neurons (there are more neurons in the brain than stars in our galaxy). Strong memories involve well-worn connections between those particular neurons. If a memory is not strengthened or refreshed, the neurons get less responsive to each other along those particular connections and the memory or image fades.


    The astral world enters into it when people who want to make money off the superstitions of others write books to part them from their money.
     
  5. Sep 3, 2007 #4
    Yes, but if these are made up by a biological aspect, how does a cell hold memory, or connections to neurons? What How is a mental image produced from a cell or neuron?
     
  6. Sep 3, 2007 #5
    Individual neurons can remember up to five previous events, five previous signals, and can connect to as many as 20,000 other neurons. Exactly how nerves and neurons work is still being worked out, however in general neurons work by passing electrical and chemical information to each other across what is called the synaptic gap. These signals are then processed in what are called neural networks, vast collections of neurons with complex interconnections. Thus far the math to describe such neural networks is still in its infancy.

    There are experiments being done that indicate the brain may also hold memories by producing proteins and in the glial cells that provide nourishment to the neurons. It requires about a hundred years for a science to mature, so I wouldn't hold my breath waiting for a definitive answer. However, great strides are being made and I find it an interesting subject to follow.

    For myself, I believe it is fair to say that memories are habitual ways of looking at the past, rather than objective representations. Our spirituality, surrender, or acceptance can then be distinguished from our memories in that it is spontaneous rather than habitual.
     
  7. Sep 3, 2007 #6

    DaveC426913

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    Yopu must understand that
    1] "a" cell does not hold a memory, it's the connections - and the connections hold ... more like the equivalent if a bit or byte each
    2] memeory recall is not a product, it's a process. You couldn't, for example, take a snapshot of a brain at the cellular level and extract what image it's holding, you'd have to let the brain do its processing and spit out the result
    3] Memory is notoriously bad at capturing details or accuracy. What you think of as a crystal clear memory or image is very, very sketchy. The brain fills in pieces as needed.

    If you know computers compress files in JPG format, you'll get the idea.
    2]JPGs cannot be read from their bits, they need to be processed to extract the data meaningfully.
    3] Much of a JPG is not from the original, it's "made up", but in ther overall picture you don't notice.
    and 4] Now imagine that JPG spread across your entire computer memory a few bytes at a time, possibly with other images sharing the same memory.

    (I wonder if this is the first time the brain's storage and retrieval system has been compared to JPG stogage and retrieval.)
     
  8. Sep 3, 2007 #7
    No one has figured all this out yet. However, we know that all mental processes are the result of the actions of the neurons because of things like the correlation of neural activity with mental states as picked up on an EEG(alpha waves, beta waves, etc.), and because of the loss of functions when neurons are damaged. After a stroke, for instance, in which the neurons governing motor control on the right side of a persons brain are starved of oxygen by blockage of a blood vessel, that person can no longer move a muscle on their left side. Likewise, in the case of severe hippocampal damage a person can no longer form long term memories. In addition there is a process by which a person's brain can be completely stopped by lowering the temperature of their blood beneath a certain point where neurons cease to fire altogether and all mental and autonomic functions likewise cease. This can be maintained for something like 90 minutes, the person's blood then warmed to normal temperature, and all previous functions return.

    Exactly how the actions of neurons add up to any particular function is not precisely known, but we are certain that all functions are dependent on the actions of neurons. If I disturb the actions of a particular part of your brain called the thalamus, for example, you will instantly lose consciousness. Were your thalamus to suffer outright severe damage you would go into a coma with no hope of ever regaining consciousness.

    I think it's safe to say that a particular memory depends on what neurons fire, in what sequence, and possibly in what rhythm. I don't think anyone can explain how those neurons firing in that sequence at that rhythm add up to the experience of memory, but as research progresses I think we'll get closer and closer to figuring out what is going on.
     
  9. Sep 3, 2007 #8
    yes what he says is true. the world is so big and there is so many things to be found out. so professors do not know much on just 1 particular subject of the mind. try asking your teacher and stuff to find out more. mayb they know something!
    haha not very likely though. here is some info about things:
    In psychology, memory is an organism's ability to store, retain, and subsequently retrieve information. Traditional studies of memory began in the realms of philosophy, including techniques of artificially enhancing the memory. The late nineteenth and early twentieth century put memory within the paradigms of cognitive psychology. In recent decades, it has become one of the principal pillars of a new branch of science called cognitive neuroscience, a marriage between cognitive psychology and neuroscience.
    (<--visit my blog!)
     
    Last edited: Sep 4, 2007
  10. Sep 4, 2007 #9
    Please repeat this after everything I post. (I pay you later.)
     
  11. Sep 4, 2007 #10
    lolz i just justified your answer
     
  12. Sep 4, 2007 #11

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    That's probably true but active memory on the other hand is stored in the state of each neuron. i.e. if you've just seen a dog, then the visual cortex has spread potentials across a number of neurons with the image data of the dog. By examining the state of each neuron (i.e. the voltage at the soma) we might be able to determine that the person has just seen a dog, and what the dog looks like.
     
  13. Sep 7, 2007 #12
    This is highly doubtful since each and every visual experience of a dog is unique and two separate views of the same dog could contain as much different information as a view of a dog and a view of a human. Viewing a dog for more than a split second would involve constant changes in all the voltages, as well, as the persons eyes scanned different parts of it and/or noticed different aspects of it. A frozen snapshot of the voltages applied upon seeing a dog might only be the information for "fur" or "drool" or "teeth" or something more elementary.
     
  14. Sep 7, 2007 #13
    memories are signals between regions of the brain that have been reinforced by hardwired connections so that when similar activity occurs in the future the same overall pattern of signals is fired up again- the pattern is constantly changing and the individual neurons and neural bundles involved being replaced/ bypassed/ re-configured and the pattern is constantly shifting- merging with and splitting from other stored patterns- you can't just look at one or a few neurons and get any information-
     
    Last edited: Sep 7, 2007
  15. Sep 8, 2007 #14
    if you are still interested, i suggest you go to the library, or get your hands on the latest copy of Chemical and Engineering news. There is a huge story in it about memory and all of the biochemistry behind it.
     
  16. Sep 8, 2007 #15

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    In perception studies, we can get fairly accurate pictures of what neurons are responding to at some immediate levels --for instance, we can stain neurons in the retina and observe corresponding firing patterns to what is in the visual field. Why can we not reverse engineer beyond that level?
     
  17. Sep 8, 2007 #16
    Well, are you familiar with so-called 'place neurons' and lab rats' dreams? The idea is that we have a mental map of everywhere we've been, so when we are in some known location (or near known landmarks), certain place cells fire. This was observed with lab rats going through mazes.

    Later, when the rats were sleeping and dreaming, the place cells would be firing and the scientists could actually tell where in the maze the rat was dreaming it was. I'm not sure if this type of reverse engineering has taken place with other sets of neurons, though.
     
  18. Sep 8, 2007 #17
    What do you want to reverse engineer? Are you thinking of AI?
     
  19. Sep 8, 2007 #18

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    That is very interesting. I have heard of place neurons, but not the rat dream studies. I would like to read more about it.

    Here's what I was thinking..
    If a thousand people were looking at simple shape, such as a black letter 'A' on a white background, there would be certain patterns of neuron firing that they would have in common. If we were to subtract out other processes and only look at what overlapped in their patterns, would we be able to map the process of perceiving that particular image? If we couldn't, would it be that we couldn't get fine enough detail, or that our individual patterns would vary too much, or something else? If we could, would we be able to look at another set of images, using this map, and determine if that person was viewing a black letter 'A' on a white background versus a letter 'Q'?
     
  20. Sep 8, 2007 #19
    I haven't read this paper yet, only saw someone say it has what I was mentioning.

    "Temporally structured Replay of Awake Hippocampal Ensemble Activity during Rapid Eye Movement Sleep", in the journal Neuron, volume 29, pp 145-56.

    http://citeseer.ist.psu.edu/cache/papers/cs/20461/http:zSzzSzwww.hsc.virginia.eduzSzed-programszSzneurosciencezSzpdfsemzSzJournalclubcole.pdf/temporally-structured-replay-of.pdf

    I like your proposed Q & A experiment (good name, no?). Someone with funding should test it out if they haven't already.
     
  21. Sep 8, 2007 #20

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    While the visual input is unique, there is likely a number of successive abstractions going on in the brain that capture only the relevant data. In a dog, the process might be to recognize certain features which are then combined into an abstract object.

    From the point on when a dog and its relevant features are identified, the brain might be dealing with the concept of dog with x and y features (encoded in the state of the neurons) and not with the original visual data.
     
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