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#26 Ishtvan

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Posted 08 April 2006 - 03:47 AM

Can you point me to the article? I'm pretty sure you are confusing the terms here. This experiment is done with light rays. Scientists were able to create devices where a single phtono was emited at a time, and this experiment shows that even then the interference effect takes places. This can be observed with electrons as well, but not with atoms. At least I have never read anywhere that you can do this interference test also on the level of an atom. If you reread that article, it would be intersting to see wether they are talking about photons (which I assume) which are NOT atoms.


Atoms and even larger things still have wave behavior, the wave-particle duality applies to everything. It's just very hard to observe wave-nature of larger objects under ordinary conditions, because, simply speaking, the wavelength of the wavefunction is very short because the momentum is very large for atoms compared to electrons, due to the much larger mass of atoms, so their deBroglie wavelength is shorter. (You can also explain it with the uncertainty principle)

Under certain conditions like extremely low temperatures, you can see the wave nature of larger particles like atoms. Here is a good talk (almost no math required) with slides and audio by Nobel winner Wolfgang Ketterle @MIT, explaining how you can cool down atoms to see the wave nature, and actually get several atoms aggregating into one giant wavefunction called a Bose-Einstein condensate:

http://online.itp.uc...cture/ketterle/

You can also do crazy things with Bose Einstein condensates like creating an "atom laser" and coherent matter waves that interfere like optical beams, which might be what DF saw.

#27 sparhawk

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Posted 08 April 2006 - 05:55 AM

Thanks. I'll check out the link. :) I have heard about this BE condensate, but never read something about it much, beyond that it is a kind of trap for atoms.
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#28 Darkness_Falls

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Posted 08 April 2006 - 09:05 AM

If you reread that article, it would be intersting to see wether they are talking about photons (which I assume) which are NOT atoms.

I'll get the book out of my car some time and quote the picture captions. In school, we all learned about the dual nature of light/photons through that slit experiment. The book was saying atoms, which is why it is strange...

#29 Maximius

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Posted 08 April 2006 - 06:15 PM

There is. That was what I tried to explain. The problem is the size. As I said before, a single neuron doesn't make a difference. A neuron is constructed of molecules and as such is way beyond bigger than a quantum particle. So if you say that a particle could influence the entire brain, it means that it has to influence the neuron. It would take a lot of particles to do this because a neuron is so much bigger. If we say that a particle can have an effect, what are we talking about? Do we mean that a single particle can switch over a neuron? A neuron requires some activty to change it's state, so we would need a big number of particles achieving this. And the chances are pretty slim, because supposedly, particles are not working to a common effort. And now that this big number of particles has managed to influence the neuron enough that it starts to change it's activity, what did we achieve? We have a single neuron doing something crazy out of how many? Millions? So how could quantum effects REALLY make a difference?
Yeah, that's what I mean, but when I look at the number, I don't see how this realisitcially can happen. if that were the case, then we should see quantum effects also in other objects.
I don't see how the possibillity of C should ever arise because of a quantum effect. Just think of the sheer numbers that it requires to have a decision.



I wasnt being very clear, I dont think a single quantum event could effect the entire brain like that either. When I said "q event" I meant the sum total of quantum "swerves" effecting neurons that should then give rise to situations like choosing C. My point is similar to your own, if quantum activity is a part of our conscious decision making process we should occasionally see bizarre results. We dont see these things, like people making ridiculous decisions like C nor do we experience this in our own lives. There definitely seems to be a sort of plateau or barrier so to speak that separates quantum activity from atomic activity in the sense that what happens at the q level doesnt directly effect the higher levels of order.

#30 Maximius

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Posted 08 April 2006 - 08:08 PM

Ah ha! I found six mp3s of Feynmans In Six Easy parts, does anyone want it? Ive never listened to it but I remember I had it on another hard drive. Each mp3 is about 50 megs long, how would I go about uploading it?

Edited by Maximius, 08 April 2006 - 09:50 PM.


#31 SneaksieDave

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Posted 08 April 2006 - 09:41 PM

Sure, might be interesting to give a listen to. I haven't followed the thread, but I have a collector's thingy of three bound books from my college years - Feynman lectures of some sort - but I never looked into them really (they were a gift... oops). I toyed with the idea of going into physics (eventually astronomy) but too many people asked me if I wanted to eat or not. Plus I really didn't like magnetic fields. The classes, not actual fields.

#32 OrbWeaver

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Posted 09 April 2006 - 05:01 AM

There definitely seems to be a sort of plateau or barrier so to speak that separates quantum activity from atomic activity in the sense that what happens at the q level doesnt directly effect the higher levels of order.


It's not so much a barrier as part of the laws of probability. The chance of massive amounts of quantum effects simultaneously occurring in such a way as to have a specific effect on a decision made by the brain is similar to the chance of cosmic rays introducing an effect on your PC's motherboard that turns your game of Doom into Quake.

#33 demagogue

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Posted 10 April 2006 - 01:59 AM

Lots of stuff going on in this thread that I'm interested in ... so I'll see what I can add.

spar: I don't think I even saved the links of the online QM lectures I found. I just d/l'ed a bunch of stuff on my hard-drive on my other computer. I can do you one better, though, and put it all in a .zip file and upload it on myfile.com or something, then I'll post the link for that. But I have to get internet access for that computer first.

As for my thinking on the topic of free will and mind ... I generally like Dennett, too. I actually took a seminar course specifically on his book Consciousness Explained (and a few other books) ... I have a bunch of nitpicks with him, too, but mostly in the details and not the larger picture, which I see as the right attitude towards naturalism. (Well captured by an old Larson (I think) cartoon which had 2 scientists looking at a frighteningly complicated math equation, except step #3 was "And then a miracle occurs" and then the equation continues. And one scientist says to the other: It's great! But I'm a little worried about your step 3 here. If any explanation has that step in it in one way or another, it's a nonexplanation.)

As for Penrose's argument, for the mind part he was heavily relying on some shoddy arguments: one a vulgarization of Searle's Chinese Room argument that the firing of neurons can't be "about" something like thoughts are "about" something; another an old hat argument that Godel's Incompleteness Theorem requires the brain to be more "open" or non-computational or something. Aside from the fact Penrose botched these arguments in their own right, both of them have aged very poorly, and even in their best days they couldn't get you far because they only support the negative thesis that Hebbian dynamics alone aren't enough for conscious thought, without lending any real guidance for what would be enough. But it's my perception that both of them, or for that matter the entire trend of anti-naturalist and anti-AI arguments you see in some circles nowadays: (1) severely underestimate what Hebbian dynamics is capable of and (2) severely exaggerate the limitations consciousness, "free will", language, logical intuition, etc., are supposed to put on the brain.

As for what *can* do the work in cases that we normally call "free will", probably the best approach is to point to some suggestive work in neurophysiology that's making the most progress, rather than trying to over-speculate.

So some of the most interesting was published in a great book by Glumcher called "Neuroeconomics" ... Bear with me a little while if you want the punchline: A lot of work on the neurophysiology of decisionmaking is concentrating on a brain area called LIP. It is the bridge-area exactly between afferent signals coming in from the retna (images) and efferent signals going out to the eye-muscles (behavior), and its function was for a long time questioned, since it didn't seem either afferent or efferent, although its wiring and behavior was very well understood. Glumcher and others have put together a fantastic case that, in fact, LIP maps "relative expected utility" for looking at something ... and when you look at its firing patterns that's exactly what you're seeing. Areas that offer a benefit to the organism get activated; areas that don't get deactivated ... and that feeds into what the eye "wants" to look at. And when the benefit to the organism changes, so does the activation. And when there are two or more areas to look at that offer the same expected risks/benefits, you see both light up, and the eye muscles hesitate between the two and over a number of cases it seems as if the eye is choosing "randomly" between the two (50%). But it's actually not "random" at all, because it's what you'd expect for an organism optimizing its utility to a Nash equilibrium (NE= any deviation from the x% pattern of choices would reduce utility). Small deviances in utility suddenly take a larger role (the little feeling you get that the right queue is a hair faster than the left queue), and there's apparently a memory that tracks choices over time so that it hits almost exactly the optimization for the Nash equilibrium over many attempts, be it 30/70%-A/B, or 50/50, etc...

So the point here is you get what looks like "random", "free", "nonalgorythmic" behavior that's actually controlled by very normal Hebbian dynamics. No need for weirdo quantum effects to get "random looking" behavior, the little oomph to choose between A or B. First of all, it's important not to see the behavior as actually *random*. The variation is actually very tightly controlled; life is like a game, and people play games to win, even being sneaky and "random looking". And because utility is at stake, the *last* thing the system wants to do when it's playing the percentages is throw *another* wildcard into the mix.

So that's one thing.
Another set of studies has to do with the actually "feeling" of volition we get while acting, when it occurs, and what causes it. I'll post this later on if there's interest ... but there is a mechanism which controls this, and what's interesting about it is that sometimes it doesn't line up with actual behavior, so sometimes we feel volition for actions we don't take (ghost limb experiments, or the "mirrored hand" effect), or even more weird but even more common: we feel the volition of choosing an action *after* the brain has already choosen it and sent the signal to the muscles. But the mechanism/feeling is not as illusionary as this suggests; there's still a core part about it that has something to do with "me" making a choice and the feeling is of that decisionmaking, not something that comes after it. Ok, that's another can of worms I'll need to take on later, and raises all sorts of phil issues of freedom and will. For now, I just wanted to explain what I didn't like about Penrose.

Edited by demagogue, 10 April 2006 - 02:04 AM.

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#34 SneaksieDave

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Posted 10 April 2006 - 08:38 AM

Maximius: I suppose you could use that rapidshare.de sitethat seems to be user-friendly enough for hosting big files?

#35 Maximius

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Posted 10 April 2006 - 09:20 AM

It's not so much a barrier as part of the laws of probability. The chance of massive amounts of quantum effects simultaneously occurring in such a way as to have a specific effect on a decision made by the brain is similar to the chance of cosmic rays introducing an effect on your PC's motherboard that turns your game of Doom into Quake.



I see what you mean. And a good analogy too. ;) I didnt think there was a literal barrier, just some reason why q events dont manifest themselves at the atomic and higher levels, at least in a direct way so that we see the effects on our behaviour.

Sneaksie: Ill look into that download site. I also have another neat MP3, its a conference at an Austrailian University featuring several cognitive scientists and the Dalai Lama comparing Western and Buddhist conceptions of consciousness. Very interesting stuff.

Demagouge: I have some questions about your long post above but I cannot get to them right now. Ill post tonight or tomorrow.

Edited by Maximius, 10 April 2006 - 12:00 PM.


#36 OrbWeaver

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Posted 10 April 2006 - 02:31 PM

I see what you mean. And a good analogy too. ;) I didnt think there was a literal barrier, just some reason why q events dont manifest themselves at the atomic and higher levels, at least in a direct way so that we see the effects on our behaviour.


The only reason quantum effects are even mentioned is because some people are absolutely desperate to believe that there is something "beyond scientific explanation" about their conscious mind, whether or not they have religious beliefs.

The funny thing is that I myself have never felt this way - it is totally natural to me to consider my own brain merely as a container for numerous competing and interacting "thoughts", which occasionally bubble to the surface and result in an action. In fact I don't see why the whole concept of "me" can't be just another thought pattern that happens to crop up more often than others (and have quite a lot of influence on the other developing patterns).

#37 SneaksieDave

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Posted 10 April 2006 - 10:48 PM

I also have another neat MP3, its a conference at an Austrailian University featuring several cognitive scientists and the Dalai Lama comparing Western and Buddhist conceptions of consciousness. Very interesting stuff.

:o That one I definitely want to hear! :)

#38 demagogue

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Posted 10 April 2006 - 11:34 PM

Maximus, you wouldn't happen to be talking about ANU ... just that I know it has a very good phil of mind program (Chalmers, F. Jackson, etc...)

The only reason quantum effects are even mentioned is because some people are absolutely desperate to believe that there is something "beyond scientific explanation" about their conscious mind, whether or not they have religious beliefs.


I generally agree with this. My feeling is that people honestly believe that "neurons just can't do it, not just 3 pounds of them ... not for *this* smell of a rose, not *this* cool feeling of water on a hot day, not *this* taste of chocolate mousse, not *this* feeling of God's presence ... and on top of all that my ability to reflect on it all and reason about it and engage with it" etc, etc... They are afraid if "that's it", then they'll lose something of the richness of life, and won't be able to engage with it on a meaningful, "spiritual" level.

I am actually a little sympathetic because I won't be satisfied with cogsci *until* it's able to give me all the richness I see in my experience, and my intuitions about "spirituality" etc ... But I regret that most people take it in the wrong direction. I am optimistic that eventually we'll be able to understand how brain-structures actually *can* and do capture these things, and far from denegrating these experiences and "spiritual life" when that starts happening ... I think that understanding their biological roots actually *opens* them up and lets you see your own experience more clearly and able to soak up the essence and "spiritual" side of life even better.

I remember reading about studies that when we see certain social actions (someone waving hello to us), the motor cortex actually activates "mimicking" actions in our corresponding motor areas, as if we understand the meaning of others actions by "feeling" ourselves mimick them; we "feel" our own arm waving with theirs ... and then I reflected on my own experience and sure enough I had a real sense of that presence in some cases! A part of my own experience which would have totally passed by me had I not been looking for it.

The other thing I don't like about that anti-science attitude is that it's really ignoring a central truth: the experience is *there* and behaves in a regular fashion *whatever* it's made of. Whether it's made out of spirit stuff or physical stuff or 11th dimensional Q-stuff doesn't matter! If it were made out of spirit stuff it would *have* to do the same job anyway and we'd have to come up with the exact same cognitive models and the same causal links to make the system work ... and then the only difference between it and "classical physical" neurons would basically come down to semantics. It just comes down to willful-ignorance; they actually don't want to know what's going on at all and the arguments that it can't be understood are just convenient ways to avoid having to ask the question.

Edited by demagogue, 10 April 2006 - 11:42 PM.

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#39 Maximius

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Posted 11 April 2006 - 09:25 AM

Demagouge, I cannot remember if its ANU or not, give me a few days guys and Ill get them posted somehow, Ive got a paper proposal to edit for this monday then Im done for the semester. God speed the day!

Im with you on the anti-science bias towards the mind but we do have to be careful and remember that whatever the mind is, it has a +very+ mysterious nature at this point in time. I too think that someday we will have the language and concepts to start to describe it in a useful, informative way but there are no guarantees either. Simply mapping the various components and sub-components of the brain will give us a part of the picture but as to what is produced when all those things work together, the mind, well it seems at least possible that the whole is greater than the sum of the parts. Not that Im afraid of a material basis or anything, Im not arguing for spiritualism, Im just saying some of the physical processes may give rise to mental processes that themselves work together to produce something more. This is the theory of emergence in simple form, I think, Im not very well read in the cogsci yet.



Hey heres the Dalai Lamas/Aussie conference!

http://www.romanpoet.org/108

Ill get those Feynman pieces up ASAP.

Edited by Maximius, 11 April 2006 - 09:30 AM.


#40 SneaksieDave

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Posted 11 April 2006 - 04:44 PM

Thanks for the link. A 26Mb MP3? Wow, that's gonna be one long listen... ;)

#41 sparhawk

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Posted 17 April 2006 - 04:11 AM

spar: I don't think I even saved the links of the online QM lectures I found. I just d/l'ed a bunch of stuff on my hard-drive on my other computer. I can do you one better, though, and put it all in a .zip file and upload it on myfile.com or something, then I'll post the link for that. But I have to get internet access for that computer first.


That would be nice. Saves me the time of finding them, though I think I will have to do this anyway. :)

As for my thinking on the topic of free will and mind ... I generally like Dennett, too. I actually took a seminar course specifically on his book Consciousness Explained (and a few other books) ...


There were courses on this book? :blink:

Funny thing is - this was one of the first books, that I started to read three times before I finished it. Everytime I read a few pages and couldn't get into it, and once I really started to read it, I was pissed off that I didn't do it before. :)

(Well captured by an old Larson (I think) cartoon which had 2 scientists looking at a frighteningly complicated math equation, except step #3 was "And then a miracle occurs" and then the equation continues. And one scientist says to the other: It's great! But I'm a little worried about your step 3 here. If any explanation has that step in it in one way or another, it's a nonexplanation.)


I know that one. :) I think philosophers have to take math now as well, but I don't think that they are usually enough of mathematicians to proove their ideas in such a way. What I really liked most about Dennets ideas is, that he tries to embedd the evolvment of a mind it into evolutionary terms using natural selection. I think this is the only correct approach, because I'm not convinced that our brain is something special (in terms of construction).

(1) severely underestimate what Hebbian dynamics is capable of and (2) severely exaggerate the limitations consciousness, "free will", language, logical intuition, etc., are supposed to put on the brain.


I never heard of Hebbian dynamics. What's that?

No need for weirdo quantum effects to get "random looking" behavior, the little oomph to choose between A or B. First of all, it's important not to see the behavior as actually *random*.


I never really believed that "random behaviour" stuff anyway, because I always had the feeling that people act rational most of the time. It doesn't mean YOUR rationality or any global rationality. Rather that, if you learn the motivation of that person, a given act is usually logical and rational from their perspective. Of course this looks like hindsight, but I think it would be possible to predict a persons behaviour if you know enough of their inner workings. As long as they don't know you are predicting them, because then this knowledge adds into the equation as well. :)

we feel the volition of choosing an action *after* the brain has already choosen it and sent the signal to the muscles.


I think I read some articles about such experiments.

But the mechanism/feeling is not as illusionary as this suggests; there's still a core part about it that has something to do with "me" making a choice and the feeling is of that decisionmaking, not something that comes after it.


Well, my brain is *me*. There is no such thing as me and my body, or me and my brain.
Gerhard

#42 sparhawk

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Posted 17 April 2006 - 04:28 AM

I remember reading about studies that when we see certain social actions (someone waving hello to us), the motor cortex actually activates "mimicking" actions in our corresponding motor areas, as if we understand the meaning of others actions by "feeling" ourselves mimick them; we "feel" our own arm waving with theirs ... and then I reflected on my own experience and sure enough I had a real sense of that presence in some cases! A part of my own experience which would have totally passed by me had I not been looking for it.


I'm not really surprised about this. :) I can do a "trick" that does exactly what you described here. When I mimick another ones face I can feel like the other one. Of course I know that this is not really true, and my mimmicking is not even that if you would watch it from the outside. BUt it gives me the illusion as if I were the other one and feel like him. It's hard to describe. And after all, that kind of self feedback is pretty often used also in other areas. Ever noticed that strange effect. You are thinking inside your head, about something and as long as it is in your head, the whole argument is perfectly logical and sensible, but as soon as you start to tell it to somebody else, you suddenly realize the flaws while you still hear yourself speaking. Even though you rehearsed it a hundred times in your head before, as soon as you speak it out loud there is suddenly a difference. I think this feedback is pretty much the same effect only bent backwards on yourself.

The other thing I don't like about that anti-science attitude is that it's really ignoring a central truth: the experience is *there* and behaves in a regular fashion *whatever* it's made of.


That may not entirely true. The problem is that you start to think differently if you learn some details about it. A musician listens differently to music than somebody else, and an artists looks differently at a picture than somebody else. I described this in other posts as well. A mathematican can see the beauty of a formula while everybody else sees just boring scratches on the board. So exploring something changes your view about it as well. I think this is inenvitable. That naive approach has some romatic quality, which is destroyed by the act of analyzing it. But that doesn't mean that this romantic view is the only one to be appreciated.
Gerhard

#43 sparhawk

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Posted 17 April 2006 - 04:32 AM

Simply mapping the various components and sub-components of the brain will give us a part of the picture but as to what is produced when all those things work together, the mind, well it seems at least possible that the whole is greater than the sum of the parts.


IMO this argument is pretty much the same if you look at a computer. Summing up the parts of it, will give you a clinical description of it's physical characteristics. If you take apart the CPU/FPU you will notice that it can do additions and other stuff with an incredible speed. That's the part where we are currently with the brain. But just from looking at the computer hardware doesn't give you an idea of what you can do with it. Looking at the sourcecode of MS Word will NOT give you any hint of which stories have been or will be written with it. It's the way that it is used that matters and simply looking at the hardware doesn't tell you much about it.
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#44 Maximius

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Posted 18 April 2006 - 08:20 AM

IMO this argument is pretty much the same if you look at a computer. Summing up the parts of it, will give you a clinical description of it's physical characteristics. If you take apart the CPU/FPU you will notice that it can do additions and other stuff with an incredible speed. That's the part where we are currently with the brain. But just from looking at the computer hardware doesn't give you an idea of what you can do with it. Looking at the sourcecode of MS Word will NOT give you any hint of which stories have been or will be written with it. It's the way that it is used that matters and simply looking at the hardware doesn't tell you much about it.



Yes, I agree. A few rather simple components acting in concert can give rise to very complex behaviour. If you inject a process of self reflection into the mix I argue you have the beginnings of intelligence. My personal theory is that our basis of our own consciousnesses isnt really all that complex compared to say another ape or other higher animals. I suspect that its only a few differences in structure that allow vastly more complex mind structure (ideas, reasons, meaning). My language is crude but I think you can see my point.


But I want to make a point about the role of Western analytical philosophy. Some folks seem to misunderstand its use. Its job is not to attempt to provide proofs like math or theories like science. At one time that was philosophy's role but that has changed. Philosophy examines our thinking about those matters. You propose a theory or a new equation, the philosopher examines your idea structure, your use of language, your assumptions about the world that surround your idea. I like to say philosophy is thinking about your thinking.

#45 sparhawk

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Posted 18 April 2006 - 08:32 AM

Yes, I agree. A few rather simple components acting in concert can give rise to very complex behaviour. If you inject a process of self reflection into the mix I argue you have the beginnings of intelligence.


I think this should be possible already. You would have to write an algorithm that optimizes the behaviour to a specified goal. There already exists scuh approaches like genetic algorithms, fuzzy logic and neural networks. Now the thing you would have to do is, to allow the computer to process it's own output similar to any other external input, just like you can hear to your own voice as well. IMO the hard part would be to define the goals in such a way that they are not to limiting.

My personal theory is that our basis of our own consciousnesses isnt really all that complex compared to say another ape or other higher animals.


That's also my assumption.

I suspect that its only a few differences in structure that allow vastly more complex mind structure (ideas, reasons, meaning). My language is crude but I think you can see my point.


From what I have heard Orang Utans are capable of rational thinking as well and would be a prime candidate for new humans, if they were not on an evolutionary downward slope because of their descendency strategy. But as it is, I don't really see this happeneing anyway, because if ever another species would evolve to such level that we currently have, I think either we wouldn't really understand it, or would take it to the zoo for public display before it could evolve to more refinment.

But I want to make a point about the role of Western analytical philosophy. Some folks seem to misunderstand its use. Its job is not to attempt to provide proofs like math or theories like science. At one time that was philosophy's role but that has changed. Philosophy examines our thinking about those matters. You propose a theory or a new equation, the philosopher examines your idea structure, your use of language, your assumptions about the world that surround your idea. I like to say philosophy is thinking about your thinking.


That's how I understood Dennets book, and that's why I don't really thought that he would have to provide a proof for his thoughts. This would be the job of the appropriate scientists in the given field.
Gerhard

#46 OrbWeaver

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Posted 18 April 2006 - 08:40 AM

But as it is, I don't really see this happeneing anyway, because if ever another species would evolve to such level that we currently have, I think either we wouldn't really understand it, or would take it to the zoo for public display before it could evolve to more refinment.


The big question in human evolution is what drove the development of our big brains and high-functioning consciousness, when it is apparent from looking at the animal kingdom that such traits are certainly not necessary for survival.

#47 sparhawk

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Posted 18 April 2006 - 09:14 AM

Evolution is not only driven by neccessity to survive. Sexual selection is also a big player in this, and this is not neccessarily direclty linked to survival. The same question could be asked of the big tails of peacocks. They are not only not neccessary, they can even be counterproductive to it, and I think there are other examples as well, that show that evolution is not exclusively about survival. I think what evolution really is about is to maximize numbers of the population. And apparently our brains allowed us to gain a very high number of individuals, because it was a successfull strategy.
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#48 Maximius

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Posted 18 April 2006 - 01:41 PM

Evolution is not only driven by neccessity to survive. Sexual selection is also a big player in this, and this is not neccessarily direclty linked to survival. The same question could be asked of the big tails of peacocks. They are not only not neccessary, they can even be counterproductive to it, and I think there are other examples as well, that show that evolution is not exclusively about survival. I think what evolution really is about is to maximize numbers of the population. And apparently our brains allowed us to gain a very high number of individuals, because it was a successfull strategy.



Did you ever get a chance to read "The Case of the Female Orgasm?" by Elisabeth Lloyd? It presents a pretty compelling case that some traits that get passed along are not selected for but rather are carried along generation to generation for a variety of reasons.

#49 OrbWeaver

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Posted 18 April 2006 - 01:50 PM

Did you ever get a chance to read "The Case of the Female Orgasm?" by Elisabeth Lloyd? It presents a pretty compelling case that some traits that get passed along are not selected for but rather are carried along generation to generation for a variety of reasons.


Is it intelligent, or just ridiculous feminist twaddle?

I think if females didn't have orgasms they would be even more unwilling to engage in sexual activity than they already are, with obvious consequences for the survival of the species.

#50 demagogue

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Posted 18 April 2006 - 02:45 PM

I haven't read the book, but I've read reviews and excerpts and an essay on the female orgasm which I think has the same punchline ... and from what I saw it seemed very insightful. Most species' females don't have orgasms the way humans do, but more like a *heat* period ... whereas this won't work for female humans because of the change in anatomy to deal with larger infant skulls/brains, so it's much harder to hit the sweet spot, so to speak ... and the whole dynamics (incentive for human women to have sex) are thrown for a loop which have interesting consequences. Quite interesting from the essay I read about it.

By the way, Dennett is notable for his other great book, Darwin's Dangerous Idea, which explains the differences between different pressures in natural selection, yeah, it's not always survival pressure (the 4 famous F's: feed, fight, flee, mate), sometimes there are archtectural constraints (the crick in humans' back for walking on 4 legs couldn't get optimized for bipedalism like birds because the change would be too radical given the current structure; so we get sore backs as we age), or simply the qwerty effect for random changes that don't have any survival impact per se... Actually, it gets nuanced pretty fast.

@spar, "Hebbian dynamics" just means the dynamics of nuerons firing over time, at various levels of scale (from single neuron chains to waves of firings across many neurons), named after Hebb, the guy that discovered the neuron. While the ground level mechanics are well known, understanding the higher level functioning is hindered by incomplete data (brain scans that try to capture firing patterns are either sortof detailed but "snapshots" with no time info, or realtime but incredibly fuzzy) ...

I've seen mathmatical theories of consciousness made out of complicated derivative formulas for the change in firing patterns over time (which are testable! ... if only the technology could catch up); I've seen chaos/emergence theory models where firing patterns occilate and consciousness is like a strange attractor (a grad student at my undergrad that first got me interested in this field, actually, Newman, who's now a prof at U Minnesota I think; this is his schtick. I have to say I was skeptical when I studied his work and didn't like the idea at the time, but I have to gather my thoughts as to why, since it's been a while since I thought about it.); holographic theories where memory/information is captured in the phase info of successive waves of firings (much like light-based holographs). The "simplest" theories are something like computational neural-nets (which are glorified S-R functions with weighted hidden layers doing the heavy lifting), which while very powerful for some tasks (pattern recognition), have turned out to be more limited than was originally hoped for I think.

Edited by demagogue, 18 April 2006 - 02:52 PM.

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