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Medical A Theory of The Brain

  1. Oct 10, 2009 #1

    Pythagorean

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    Is there a consensus on the current theory of the brain that can be agreed on by neurologists and psychologists alike? Perhaps even philosophers (real ones that acknowledge physical sciences). The philosopher I like a lot is Daniel Dennett. He rejects the http://en.wikipedia.org/wiki/Cartesian_theater" [Broken] as he calls it.

    I myself want to get into the theory of the brain. I don't necessarily want to do neuroscience, but I definitely want use the the data provided by neuroscience to test some theories that are out there (If I can find a quantitative way to do so) and develop and strengthen those theories.

    My undergraduate training was in Physics and my master's training is currently with Electrical Engineering, so I realize I will have to learn a bit about chemical potentials.

    So I'd like opinions about the theories I've found so far, anyway, and whether my interpretation of them is valid:

    Gestaltism and Structuralism

    This the definition of Gestaltism according to wiki. It's probably the only part of Gestalt theory that I don't agree with. Not that I disagree... I just don't really see the relevance or a way to quantify this statement. I am perhaps too ignorant to make a decision at this point.

    This is particularly alluring to me. It seems to make sense with the way different regions of the brain are best known for their functionality. I think that synesthesia is particularly suggestive of this...

    but I don't see how this is opposed to structuralism ("a complex system of interrelated parts." -Wiki), and in fact, if we look at the neuroscience side of it, the synesthesia is directly a result the locality of the particular sensory (and number identification) regions of the brain responsible for with respect to one another. The neurons are much more likely to find each other. Vilayanur Ramachandran claims that, as well, we see that people who are more likely to have synesthesia are also more likely to be artists, and goes a little bit into grasping metaphors. Here's his talk on TED, it's pretty interesting:


    Am I making a mistake tying things like emotions and creativity more tightly to the idea of consciousness than, say... pattern recognition and motor skills?

    I'm still not sure what consciousness really is. It's a very intangible concept to me, yet I still feel like I experience it... and I don't think I could feel that way if I didn't. Remembering Daniel Dennetts opinion on the http://en.wikipedia.org/wiki/Cartesian_Theatre" [Broken] tends to raise doubts about it. There's many unanswered questions. Are there many levels of consciousness? Are animals conscious? Are we the most conscious beings on Earth? is a "level of consciousness" even a valid phrase?

    Of course, if consciousness does exist, it must rely on the physical state of the central nervous system (probably not a surprising expectation from a physics degree holder).

    Are there any more obscure theories, or even popular theories of the brain out there?
     
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  3. Oct 11, 2009 #2

    Monique

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    I watched a documentary not too long ago about a neurologist that was helping a colleague in the Ukraine to set up facilities to do complex brain surgeries in low technological surroundings. It's called the English Surgeon, a deeply moving documentary. You should definately watch the http://www.youtube.com/watch?v=mZdgwI0rx3Y&feature=player_embedded#".

    Anyway, the reason I bring it up because the surgeon is operating on the brain of a conscious patient and he is removing a large tumor in the process and he comments something in the lines of "I can't believe I am cutting away in this brain, this is where all his thought processes take place and his memories are stored".

    The brain is still a large enigma. You might enjoy watching the OpenYale courses in psychology http://oyc.yale.edu/psychology (I've enjoyed watching a few of the lectures and they give you some basic training in the subject).
     
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  4. Oct 11, 2009 #3
    consciousness is just awarness of awarness. thats pattern recognition, not emotion.
    we can never be aware of what determines our actions since that awarness tiself changes things. the result of the feeling that nothing determines our actions. that we have freewill.
     
  5. Oct 11, 2009 #4
    A cartesian theater is obviously useless for explaining consciousness but it would ntill be useful for explaining our ability to predict the future (not just years in the future but even just seconds or fractions of a second into the future)
     
  6. Oct 11, 2009 #5

    Evo

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    Pythagorean, you mention two completely different areas, the physical brain and then philosopical writings about consciousness. Ramachandran is looking at the physical causes of brain abnormalities. These physical abnormalities result in delusions.
     
  7. Oct 11, 2009 #6

    Pythagorean

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    The trailer does look interesting. Operating on conscious patients! That very much highlights the idea here, a sort of marriage between psychology and neurology.

    I would be interested in psychology, but I'm still arguing with myself over whether I should learn the neurology or the psychology first.

    Yes, it is my assumption that consciousness can be explained by physical processes in the brain. Daniel Dennett (the philosopher) holds respect for neuroscience in his philosophical explanations of the brain and consciousness (this is the point of the Cartesian Theatre).

    People like Ramachandran keep us grounded in the hard sciences, but I don't think his research is irrelevant to consciousness at all.

    Christof Koch is a neuroscientist that studies consciousness. (here's his webpage on the subject: http://www.klab.caltech.edu/~koch/crick-koch-cc-97.html [Broken]

    But, the ultimate point is that we have to start from somewhere, and philosophy has always been a place where generalizations are made about subjects that can attempt to be verified. As I pointed out in my first post, some of the philosophical statements are impossible to quantify, but when they are not, verification is possible and helpful!

    A canonical example of this is Aristostle. Galileo and Newton both used Aristotle's statements as starting points for experimentation (disproving him in most cases).

    I suppose though, that you could pick on me for my fundamental assumption: That a theory of the brain would ultimately require an understanding of consciousness.

    I don't know if you can separate the two in a theory of consciousness. It's been said in baby development that even highly technical skills like mathematics are initially learned through emotions. Saying consciousness is "just" anything immediately raises my suspicions of whether people want to remain ignorant about a subject. It's as if you've already given it all the thought and came to your conclusion while there's still literally millions of people (experts, none the else) that are still trying to understand it.

    I don't follow
     
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  8. Oct 11, 2009 #7

    Q_Goest

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    Hi Pythagorean
    There is a general consensus, though not a proven one. It’s highly debated. It’s called computationalism. Regarding the cartesian theatre, I don’t think anyone really believes in some kind of cartesian theatre today. It’s a useful explanation for teaching the basic ideas, but Dennett IMHO hasn’t told us anything we don’t already know. Also, if you study philosophy long enough, you’ll find that most philosophers have a very good understanding of physics and do their best to base their logical arguments on hard science. Generally what I’ve seen is people don’t really grasp what it is they’re saying, and chalk it up to philosophical mumbo jumbo. I’ve seen many philosphers discuss quantum mechanics for example, in ways only a practicing physicist would understand.

    It sounds a bit like you’re confusing concepts about neuroscience with concepts about cognition. A neuroscientist or neurologist isn’t really investigating consciousness, they’re investigating the interactions between neurons. They’re investigating the material world and how it works, things that are commonly called, “the easy problems of consciousness”. They are not studying, nor are they really trying to explain, how the various conscious phenomena come about (ie: the "hard problem").

    Consciousness is best understood as a phenomenon. It is something that occurs. Our experiences, such as the experience of color, the way things taste, how hot or cold something feels, the experience of desire, anger, love, etc… are all various types of phenomena which occur within our brains. Such experiences or feelings are, or are not, explained by explaining the interaction of neurons. This issue is called “the explanatory gap”. Consider this; if we explained how all the neurons are interacting and what they did and why, would we be explaining what it feels like to fall in love or to taste chocolate or what a sewage pile smells like? Can we relate the experience we are having to someone else by explaining which of our neurons are interacting and with what other neurons they are interacting with?

    About the explanatory gap, Chalmers has pointed out:
    *When Chalmers talks about philosophers in this context, he’s also refering to scientists who attempt to explain conscious phenomena such as Christof Koch, who is a hard line computationalist.

    For what it’s worth, Dennett would fall into category (1). He would say that once you’ve explained what all the neurons are doing and how they interact, there’s NOTHING LEFT TO EXPLAIN. Dennett in fact, has gone on record as saying that qualia simply don’t exist. Dennett is at one of the far ends of philosophy, and from what I know of him, he’s lost much of his following because of his extreme views.

    Anyway, at this point in time, consciousness is primarily studied by philosophy, not science, unless you subscribe to Dennett’s view that qualia don’t exist and are not worth chasing. Science does of course study people's behaviors, how neurons interact, and everything in between. Understanding the difference, understanding why any of those physical interactions should be accompanied by something we call feeling (or experience or qualia) is necessary to understand the explanatory gap. It is this gap which separates our material understanding of this world from our understanding of conscious phenomena.
     
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  9. Oct 11, 2009 #8
    my mistake. I thought the theater was being performed by lots of little actors (one for each object and/or person we perceive). instead its just a projection of our senses (like vision) directly onto some internal screen.
     
  10. Oct 11, 2009 #9

    There was a tangent on another thread that brought up this topic. I personally fall into category (2). I can not for the life of me understand Dennet's position. How can one deny the existence of qualia? There's no way to prove qualia (which I guess is his point?) so you're sort of left with an impenetrable wall where argument is shut down. It's like someone insisting that they are the only consciouss person in existence. You know for a fact that they're wrong, but you have no way to prove that to them, so you're just kind of stuck. For all I know, maybe Dennet isn't consciouss and that's why he doesn't get qualia.
    It's just such a silly and frustrating argument. It's like my friend who believes he is the smartest man in the world and invented a system of circular logic to justify the conclusion.
     
  11. Oct 11, 2009 #10

    Pythagorean

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    On the Cartesian Theatre, I don't think he's necessarily said anything that we don't know (our instant agreement with it is a sign of that) but he's put it into words and demonstrated a concept that I didn't have words for before.

    On Philosophers and science... when I said real philosophers I meant as opposed to the armchair philosophers that physicsforums is famous for. But when it comes to quantum mechanics, I do really feel like a mathematical understanding of QM is necessary to understand it conceptually, as it's not intuitive at all, and the intuitive explanations are often interpreted overbearingly and carried too far into a macro-world mindset. In some sense, it shouldn't be explained without mathematics.

    I understand the discrepancy. In my opinion, neuroscientists like Koch are really studying consciousness though, despite your semantics, just not the full breadth of it. I think consciousness is a bigger phenomena than either philosophy or neuroscience, and can successfully encompass both.

    What you have to understand is that I'm window shopping right now and haven't made up my mind. I'm refraining from taking sides (within my ability to do so). I don't have the problem of conflict between disciplines that lots of people seem to espouse. I understand that love can't be explained in its entirety with physics, but I (unlike many of my young physics peers) don't think love is irrational and useless.


    This doesn't conflict with my developing ideology at all. I mean, not in the way you mean it. If I wanted to cherry pick, I could argue that we can see what the neurons are doing when someone is feeling love and that is a sufficient start, but I suspect you're onto something a little different which I don't disagree with (as I might have hit on in my last paragraph in this response).



    I don't particularly agree with Dennett on that point, but like I said, I'm not taking sides yet. I'm highly ignorant; I'm sticking out my feelers at this stage. Of course, I can't help but come to some conclusions (it's part of the learning process).

    Also, I'm not trivializing your post either. I appreciate your thoughtful response.

    I don't think they are mutually exclusive, personally. They obviously don't completely overlap, but they do overlap and I believe that it is from that overlap that a general theory of the brain is likely to emerge.

    Apparently, it is the gap that I'm interested in studying. Ideally, I haven't taken a side, but obviously my struggle to understand is pointless if I'm not a [2].

    But I think it's important to realize that just because Dennett is a [1], doesn't mean some of his ideas can't be used by a [2].
     
  12. Oct 12, 2009 #11

    Pythagorean

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    On Computational Theory:

    I think I've had some exposure to this through Jeff Hawkins, inventor of the PDA and founder of the Redwood Center for Theoretical Neuroscience. I would love to do my PhD there if I could bare two switch subjects and get in! Thought I don't see getting in being very easy.

    Anyway, Hawkins has a presentation that inspired this thread:
    http://www.ted.com/talks/jeff_hawkins_on_how_brain_science_will_change_computing.html

    It's entertaining but I've been told he misrepresents information by a developmental biologist master's student. He tends to be a contrarian though, so I'd like to hear any input from professional neuroscientists.
     
  13. Oct 15, 2009 #12

    Pythagorean

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    I've been watching these lately. Good find. Psychology is a lot more grounded in hard sciences than I had previously suspected (according to this lecturer, neuroscience is even a branch of psychology!).

    I've now designed my interdisciplinary Master's degree. I call it "Nonlinear Systems with a focus in neuroscience" and it centers around neural networks and control systems from an EE perspective, but also involves some psych and neuro graduate classes and I'll be going back to my physics department for nonlinear dynamics.
     
  14. Oct 15, 2009 #13

    apeiron

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    Hi Pythagorean

    You are really asking the question of what is the correct level of explanation in which to ground an account of consciousness, a science of the mind? Various candidate levels are being suggested here - philosophy, psychology, neurology, information theory. So which should you study as the place to start?

    The study of the mind is not really ameniable to this usual reductionist, bottom-up, perspective where you start at some particular scale of analysis and then everything else makes sense (in the way that understanding atomic structure then explains molecular properties for example).

    Instead, you need some kind of organised and systematic holism or systems view. And authors like Dennett, Koch and Chalmers will not help you get there.

    Hawkins is more on the right track, but is one of those characters (like Gerald Edelman)who does not realise how much he is simply re-inventing the wheel.

    Treating the brain as an "anticipatory machine" is in fact a very good way to start understanding it. But there are a whole bunch of neural networkers who have gone further than Hawkins, such as Stephen Grossberg with his ART models, and many others under various rubrics such as generative neural nets, forward models, Kalman filters, predictive coding, dietic coding, Helmholtz engines, etc, etc.

    For your studies, the question "how does the brain anticipate/predict the world" would indeed give you a good level of focus. It could be inspired by the psychology and neurology data, of which there is plenty, and then generalised as computational models (non-linear and otherwise).

    So the most powerful thing to do here is take the brain as a particular organ performing a general function that can be captured mathematically. And anticipation is the broadest label for that process. It is what makes consciousness in Dennett's (dreadful) term "intentional" - the quality of aboutness and contextuality.

    But while you fix on what brains (and nervous systems generally) do - anticipate the world - it would also be useful to invest some time in social psychology. Read some Vygotsky in particular. The human mind is scaffolded by its use of language and this is responsible for the "higher powers" we associate with human level consciousness.

    And above all, avoid becoming bogged down in phenomenological questions about consciousness - the hard question, qualia, theatres and all that. This has killed mind science again and again.

    Phenomenology is the natural academic counter response produced by any attempts at scientific reductionism. If one is pushed, the other must arise as its foe. And the science veers off the road again. A systems approach is the only way to avoid this fate.
     
  15. Oct 15, 2009 #14

    Pythagorean

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    Thank you for your reply! I have begun to design my interdisciplinary degree after talking to a physics professor of mine and it happens to include a lot of what you're saying.

    My mother discipline is going to remain the Electrical Engineering department, from which I'll get a 'neural network' and 'modern control' viewpoint. I will also be attending psychology and neuro, and nonlinear dynamics from the physics department.

    My fancy, far-fetched goal is to find a better alternative to neural networks, or at least, to improve on neural networks (this is what my thesis work will be based around) as a tool for studying the brain. I kind of want to investigate hybrid neural networks too. Of course, I really know nothing about these objects besides what they are superficially, but I'm definitely fascinated by the psychology classes that Yale put online.
     
  16. Oct 15, 2009 #15
    while we are talking about theaters you might be interested in knowing this:
    everyone knows that there is a motor and a separate sensory part of the brain for each part of the body. (See http://en.wikipedia.org/wiki/Cortical_homunculus). what you might not know is that apparently there is a part of the brain that maps out the space immediately surrounding ourself. (within arms reach I think)
     
  17. Oct 15, 2009 #16
    Hawkins also came to Purdue and did a similar presentation, and I discussed his views with my older brother who is doing Child Psychiatry Residency at Johns Hopkins - and he didn't like the concept of " a theory of the brain "... He also watched the TED talk; and somewhat disagreed on some points raised by Hawkins.

    What exactly does he imply by saying "we do not have a theory of the brain"? There's surely a huge amount of research on the brain, but we have to admit that we are very far away from a complete bottom-up description of the brain.

    I think it is similar with what's happening with the theory of superconductivity. First came the observations, then phenomenological theories, and then partial success with bottom-up theories...
    Still we have no clue about what's happening in high-Tc superconductors.

    Brain, of course, is probably much more complicated and really, I don't think there's even a hint of a progress in the bottom-up view of things like Hawkins suggests. It could be a long, long time before the brain riddle is solved, if there's a mystery at all.
     
  18. Oct 15, 2009 #17
  19. Oct 17, 2009 #18

    Pythagorean

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    I think he meant a theory, not theories. Kind of like how fundamental F=ma is to motion, or Conservation of Energy, or Conservation of Matter. Having lots of different halfway working theories is a sign of a science still being developed as far as theory goes. Not that I think I will see such a thing for the brain in my lifetime, but I'm not discouraged from working towards it yet.

    I believe Physics is topdown. Physics, for example started off with very intuitive guesses and generalized concepts based on direct experience (aristotle). As it became more grounded in reality and experimental verification became important, it became a little bit less intuitive, but not terribly unintuitive (classical physics, starting with Kepler and Galileo and ending). Newton tied the general basic theory together rather nicely with his three laws.

    (I have no idea where conservation comes from historically... it kind of sneaked in to the classroom.)

    And the quantum mechanics came along and described, more fundamentally, the classical observations with crazy unintuitive ideas.

    But "top-down" and "bottom-up" describe linear models of discovery. It may be that this is how the community of scientists develop science as a whole, but it doesn't mean that particular scientists are restricted to viewing things that way.

    Now that I think of it, we almost nearly always have to test thing from the bottom-up, because once we learned quantum mechanics, for instance, there were theories in classical physics that became invalid as they had made fundamental assumptions that were not true in general. But as far as I know, you can recover nearly all of classical with quantum when you make those same assumptions with QM and take the limit. So we see a sort of way we can quantify reductionism.

    I've gone off on a tangent, but what I'm trying to say is that we should generally always be able to recover the top from the bottom if we make the right assumptions at the bottom. And the top will always make sufficient predictions in the limit that we're generally comfortable with because it generalizes the intricate parts of the bottom, so both schools of thought "bottom-up" and "top-down" are valid in a sound scientific theory.

    Anyway, in some sense, I predict that neurology will be the QM of psychology (which will play the part of classical physics).
     
  20. Oct 17, 2009 #19

    Pythagorean

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    There was a language lecture in the Yale set (last one I watched, actually) and the lecturer brought home how fundamental language is in human psychology. Of course, I've heard it before and generally agreed with it from experience. It's hard to think about, store, or learn anything without language even when you do it internally.

    My knee-jerk response was "oh god, language is so hard to code", but I'm definitely interested in the idea. That's more of a postdoc project than even a PhD project, and I'm only just thinking of Master's project for now. From what I've read so far, it's likely to draw on the firing-rate model.

    Well, I don't suppose getting bogged down (at least not for the long-term) is likely to happen, but I definitely can't help but be very emotionally attached to phenomenological questions, and want to find solutions to answering them.

    However, I think these things emerge in the strangest ways if we don't pay attention to them. I especially like Vilayanur Ramachandran's tangent on synethsesia and its connection to creativity... this would be worth investigating to me. If you haven't watched his video, I referenced it earlier in this thread and will do so for you again as I'm desperate to share discussion on it and want to make it as easy as I can for you to watch it in the hopes that you will:

     
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  21. Oct 17, 2009 #20

    apeiron

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    But what's the question exactly?

    Under-pruning of synapses would be the standard speculative story on synesthesia. Stuff spills over. And conversely, a well-organised left fusiform gyrus would act as a "module" for orderly cross-modal tieing together (though perhaps more an evolutionary emphasis on language processing that any kind of human creativity module). But anyway, you have two kinds of neural story here - one of overly diffuse connection, the other of focused connectedness.

    If anything, this would lead into a discussion of brain organisation as a set of dichotomies. So diffused~focused. Or plasticity~stability to pick a more telling dimension for neural net design.

    Actual creative leaps are probably best modelled in threshold terms - competitive neural nets.

    When the mind is fixed on one idea, it cannot see other possibilities. It is in a state of high neural contrast where something is very conscious - high firing rates, high synchrony - and all other memory traces literally suppressed. Low reactivity. low synchrony.

    So to jump to some other version of events, some other arrangement of stored knowledge, the mind has to relax. Go flat. Then competition can bring another pattern of connections to the fore. Forge a new link - this could be flipped round to now fit that.

    This is why solutions often pop into mind when we are "looking the other way" - relaxed theta rhythm story, or check the priming literature.
     
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