Register to reply

A Theory of The Brain

by Pythagorean
Tags: brain, theory
Share this thread:
Pythagorean
#1
Oct10-09, 04:02 AM
PF Gold
Pythagorean's Avatar
P: 4,287
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 Cartesian Theatre 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

Quote Quote by Wiki
The Whole is Greater than the Parts
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.

Quote Quote by Wiki
Totality - The conscious experience must be considered globally (by taking into account all the physical and mental aspects of the individual simultaneously) because the nature of the mind demands that each component be considered as part of a system of dynamic relationships.
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:
http://www.youtube.com/watch?v=Rl2LwnaUA-k

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?

Quote Quote by Wiki
Principle of psychophysical isomorphism - A correlation exists between conscious experience and cerebral activity.
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 Cartesian Theatre 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?
Phys.Org News Partner Medical research news on Phys.org
Senegal monitors contacts of 1st Ebola patient
Snacking while watching action movies leads to overeating
Quality of US diet shows modest improvement, but overall remains poor
Monique
#2
Oct11-09, 06:49 AM
Emeritus
Sci Advisor
PF Gold
Monique's Avatar
P: 4,642
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 trailer.

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).
granpa
#3
Oct11-09, 12:12 PM
P: 2,258
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.

granpa
#4
Oct11-09, 12:14 PM
P: 2,258
A Theory of The Brain

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)
Evo
#5
Oct11-09, 06:42 PM
Mentor
Evo's Avatar
P: 26,557
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.
Pythagorean
#6
Oct11-09, 07:24 PM
PF Gold
Pythagorean's Avatar
P: 4,287
Quote Quote by Monique
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 trailer.

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).
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.

Quote Quote by Evo View Post
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.
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

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.

Quote Quote by granpa
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.
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.

Quote Quote by granpa
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)
I don't follow
Q_Goest
#7
Oct11-09, 08:43 PM
Sci Advisor
HW Helper
PF Gold
Q_Goest's Avatar
P: 2,907
Hi Pythagorean
Quote Quote by Pythagorean View Post
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 Cartesian Theatre as he calls it.
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:
Well, like most questions in philosophy, there is no consensus. Certainly, no specific proposal for closing the explanatory gap has attracted much support. I think that the most common view by far is that there is a fairly deep explanatory gap, but there's a lot of disagreement about whether that situation is temporary or permanent, and about what follows from this. My sense of the sociology is that philosophers* divide into four (very roughly delineated) groups of roughly equal size:

(1) There's no explanatory gap, or one that's fairly easily closable.
(2) There's a deep explanatory gap for now, but we might someday close it.
(3) There's a permanent explanatory gap, but not an ontological gap (so materialism is true).
(4) There's a permanent explanatory gap, and a corresponding ontological gap (so materialism is false).
*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.
granpa
#8
Oct11-09, 10:02 PM
P: 2,258
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.
Galteeth
#9
Oct11-09, 10:52 PM
P: 320
Quote Quote by Q_Goest View Post
Hi Pythagorean

There is a general consensus, though not a proven one. Itís highly debated. Itís called computationalism. Regarding the cartesian theatre, I donít think anyone really believes in some kind of cartesian theatre today. Itís a useful explanation for teaching the basic ideas, but Dennett IMHO hasnít told us anything we donít already know. Also, if you study philosophy long enough, youíll 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 Iíve seen is people donít really grasp what it is theyíre saying, and chalk it up to philosophical mumbo jumbo. Iíve seen many philosphers discuss quantum mechanics for example, in ways only a practicing physicist would understand.

It sounds a bit like youíre confusing concepts about neuroscience with concepts about cognition. A neuroscientist or neurologist isnít really investigating consciousness, theyíre investigating the interactions between neurons. Theyíre investigating the material world and how it works, things that are commonly called, ďthe easy problems of consciousnessĒ. 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, etcÖ 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 ďthe explanatory gapĒ. 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, heís also refering to scientists who attempt to explain conscious phenomena such as Christof Koch, who is a hard line computationalist.

For what itís worth, Dennett would fall into category (1). He would say that once youíve explained what all the neurons are doing and how they interact, thereís NOTHING LEFT TO EXPLAIN. Dennett in fact, has gone on record as saying that qualia simply donít exist. Dennett is at one of the far ends of philosophy, and from what I know of him, heís 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 Dennettís view that qualia donít 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.

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.
Pythagorean
#10
Oct11-09, 11:33 PM
PF Gold
Pythagorean's Avatar
P: 4,287
Quote Quote by Q_Goest View Post
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.
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.

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").
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.


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?
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).



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.
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.

Anyway, at this point in time, consciousness is primarily studied by philosophy, not science.
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].
Pythagorean
#11
Oct12-09, 02:24 AM
PF Gold
Pythagorean's Avatar
P: 4,287
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_hawkin...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.
Pythagorean
#12
Oct15-09, 01:33 PM
PF Gold
Pythagorean's Avatar
P: 4,287
Quote Quote by Monique View Post
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).
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.
apeiron
#13
Oct15-09, 07:11 PM
PF Gold
apeiron's Avatar
P: 2,432
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.
Pythagorean
#14
Oct15-09, 07:29 PM
PF Gold
Pythagorean's Avatar
P: 4,287
Quote Quote by apeiron View Post
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.
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.
granpa
#15
Oct15-09, 07:31 PM
P: 2,258
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)
sokrates
#16
Oct15-09, 08:42 PM
P: 483
Quote Quote by Pythagorean View Post
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_hawkin...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.
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.
Galteeth
#17
Oct15-09, 10:00 PM
P: 320
Someone you might find interesting in the conext of an interdisciplinary approach who has done interesting work with computer AI:

http://en.wikipedia.org/wiki/J%C3%BCrgen_Schmidhuber
Pythagorean
#18
Oct17-09, 12:56 AM
PF Gold
Pythagorean's Avatar
P: 4,287
Quote Quote by sokrates View Post
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 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 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.
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).


Register to reply

Related Discussions
Big Brain Theory: Have Cosmologists Lost Theirs? Cosmology 18
Brain Computer Brain interface, anyone? Medical Sciences 16
How does the Medieval brain compare to the modern brain? Medical Sciences 27
Left brain vs. Right brain personalities Biology 15