(originally posted here∞)


Curious as to the implications:

- do the thoughts present at time A cause the thoughts at the next instant B? in other words, how often does the spirit intervene, and how would we distinguish it from chemistry?
- if the damaged brain were replaced with a new one, would the spirit remain the same?
- what is neural origination? you mean one neuron or cluster controls all the rest?

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Even Descartes had trouble reconciling his theories on Mind-Body with the equally "obvious" notion that two things which interact in a causal way must share some common attribute (beyond the circular argument that they belong to the same event sequence). There's plenty more if you Google "dualism* causality" or similar -- most of it bad, but even bad philosophy is good for your intellect.

*the division between that whose existence we know a priori, and that which we must take on faith to avoid Idealism

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Naturally quantum effects at the level of enzymes are fascinatingly irrelevant, diverging interactions from those predicted by deterministic chemistry on the order of 1 in a million-jillion occurrences. Even if probability were a factor, however, I'd consider this more troubling. We don't normally consider free will to be a matter of pure chance.

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If someone is happy with that definition of free will, it's not inconsistent or anything. I just don't think that answers most of the questions people have. For instance, who/what assigns the weights? (I.e., one's belief systems + situational ethics.) Are we happy with black-box functionalism encapsulating what feels like very real consciousness?

I think physicalism* is quite logical, but I have a feeling I'd have a hard time convincing Amka of it.

*the world should be thought of as consisting of algorithms, data structures, and intentionality

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2 pages of others' discussion

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The two share some design patterns, namely massive parallelism, but I don't think the brain is anywhere near approaching the scale of Google. The smartest people of a generation can hold ~100k digits of pi, or the contents of a bookshelf of medical references, or the score to every symphony in the repertoire. Amazing feats, but nothing rivalling a 300GB hard disk.

The unique parts of the brain are its suborgans for processing speech and vision. They are extremely difficult to match because they represent specialized hardware evolved to specific and complex tasks; present-day computers have to get by with software emulation, as it were.

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The brain's sensory inputs are massive, yes, but its storage is very finite. Google doesn't remember the millions of pages of links that it generates millions of times a day; it remembers the index. The brain doesn't even do that much.

I'm not sure what you mean by visual memory being immense. It's immensely perceptive in some ways -- face recognition is one application that's hardwired and difficult to simulate. But how many faces can someone really remember? Let's be inordinately kind and say 100,000. Lots of distinct features there, but they're undoubtedly stored as patterns (compression). 100k JPEGs is nothing to a disk, and it will preserve a lot more detail to boot. As well as you know someone's face, could you paint in a 1000x1000 image?

Scenes are bigger, of course. A 300GB disk can "only" store 50 days or so. But that's storing (in some intelligent fashion) every pixel of every frame. Could you reconstruct some given frame N exactly? For **all** N, 24 each second? Not a chance.

Please give some real evidence before rolling your eyes.

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Complexity != storage capacity. There's no doubt we perform extremely difficult calculations, but all the evidence we have points AGAINST doing so via a giant lookup table.


And notably, they didn't achieve this by adding more and more disks. They did it by working smarter.

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You're misquoting me. I think it was obvious to everyone else that we were discussing the complexity of the problem (walking) and therefore the complexity of its solution. This is completely independent of the details of the storage system being used. Algorithms do take up space, yes, but they take up a lot less than you think. I'll bet the source code to every algorithm ever submitted to a major journal would fit comfortable on a CD-R.

I have seen no evidence offered that the internal logic of the brain requires several orders of magnitude more space. There are certainly no trends in CS research that indicate a correlation between code size* and efficiency.

*Let's be crystal clear and say we're talking about the text segments of object files (a gzip'd repository is too language-dependent, though still nowhere near creating order-of-magnitude differences). You have to link to so many libraries these days that executable size is misleading.

The reason even the most advanced computer systems need human guidance to do is because a computer system cannot imagine something up from nothing.

Neither can a brain, unless you're about to switch sides and resort to completely independent influences. (That stance practically defines dualism.)

If you don't think that is pertinent, then I really can't help you

The question is somewhat pertinent from an inquisitive point of view. I just don't give any credence to your answer.

You keep thinking "how many frames per second" is some kind of incredible indication of capabilities, when the human mind is so advanced it doesn't even need to break something down into frames. It sees real motion, and modern technology can't even come close to copying that.

I work with desktop video every day from both a developer's and user's POV, so I know computer processing and storage is not magic. It is, however, far superior to a human's. "Breaking something down" is lossy data compression -- very, very lossy. Unless you have a startlingly insightful definition of "real motion," I can't think of any way in which the brain can compete.

This is not an indictment of overall brain capability. There are many areas (which I've already listed) where its internal data structures perform vastly better than anything we've come up with. But it does debunk the notion that visual memory is one of them, instead more akin to tasks like multiplying 100,000-rank matrices that everyone has to agree give computers the edge.

However, Richard, you keep coming off as a typical "computer geek" guy who thinks that because he uses a computer a lot, he knows a lot about how all computers work.

Please. I've taken graduate classes in computer architecture, operating systems, AI, and numerical machine learning.

It's you who seems bent on assigning grandiose attributes to the brain that are not supported by the evidence. Just because our high-level and biochemical descriptions of brain activity haven't been unified into a single theory doesn't mean the intermediate processes deserve mythical status.

. The human body, when it runs, is not just executing a specific set of instructions. Every step is handling the controlled movements in direct relation to the body and the ground

Precisely. Our abilities don't hinge on 100 million if-then statements; the exact mechanism is unknown, but it's certainly much closer to fuzzy logic, pattern recognition, and other processes that drastically reduce the necessary storage capacity from what you claim.

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Actually, I think the limit is more like 10GB, maybe 50GB if we're feeling kind to our geniuses. I know you'll step in to get the last word, but I'm through discussing this subtopic until there's some evidence and/or reasoning demonstrated.

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Finally, something to work with.
(me quoting John L) This gives a total of (very roughly) 100 terabytes for the brain.

This is completely fallacious. One could similarly claim: disk platter substrates are made of aluminum alloys; each molecule in a metal crystal can assume 100 states (in reality it's a lot more...); therefore any disk that weighs 100g can store 100 ^ (100 * 6 * 10^23) bits. Not.

Without a working model of memory, our only recourse at the moment is to approach the problem from neuropsychology -- what limits on information storage have we observed in the real world? Numerical and text data is no contest, obviously; images and scenes I've covered; algorithms were treated in detail with no objection. What else is there? Put up or shut up, as they say.

Pod has the right idea. We have no idea what the mapping function between memories and neurons looks like. Any claim to perform calculations on these unknowns is at best a shot in the dark, and at worst a defensive agenda reminiscent of 19th century chemists who thought organic molecules were too complex to be synthesized. Unfortunately for them, we've already achieved the computational equivalent of urea, and whether it takes "a few centuries" or a few years is irrelevant.

I too think it will be on the 100+ year timescale, but that doesn't invalidate some core truths. Digital computers, for all their weaknesses, are still Turing-complete. Organic brains, for all their strengths, still cannot break the laws of information theory.

This is what I hate about computer geeks

Hint: repeated arguments ad hominem don't make you look good


I never said anything like this! Scroll back to where I reentered the thread -- everything from then to now addressed what I first thought was a piece of pure hyperbole regarding organic storage. I addressed "power" only when refuting a secondary claim that solving certain complex problems (vision, language, locomotion) required 10+ orders of magnitude more space than every other problem we've come across.

FWIW, even that silly 100TB figure isn't in Google's class. Now to something interesting...

Pod, I've read Penrose, Hofstadter, Lucas, etc. and I'm far from convinced that Godel incompleteness is a roadblock for AI. The theory that models intelligence as theorem-proving was pretty much discarded by the late '70s as one that shed fascinatingly little light on the main dialectics of philosophy of computation: meaning/mechanism, syntax/semantics...

Even aside from these important theorems, we have to establish some basics before we start talking past each other. I think bringing up Godel is a red herring similar to bringing up Turing's Halting problem. The brain-apologists will look at this limitation imposed on computers and immediately claim themselves superior. But do they really believe a brain is immune to Turing's criticism? Maybe so on principle, but in practice can anyone volunteer to solve the Halting problem themselves? I wouldn't want to be first in line. Back to Godel, I think it's even more wrongheaded to suggest a human can "see" the "inherent truth" in a Godel statement -- not only because we lack the quasi-spiritual ability, but because there's no such thing.

Note: I think much of what McCarthy, Chalmers, Maudlin, and the rest of that crowd say is equally stupid.

(edit) In hopes of keeping at least some of us on a philosophical bent, I'll list some other important dialectics: [what it means to be] abstract/concrete, static/dynamic, one/many (cardinality). The essential one -- meaning/mechanism -- was already mentioned, but important enough to be repeated. It represents the computational equivalent to the mind/body problem in metaphysics.

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Did Smith give any indication what he meant by "refined?" That could help...

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I've claimed (agreed from the start, actually) that the differences in underlying topology make direct comparisons invalid (although we do have enough information to discard complete fallacies like the 100TB remark). Even if you wanted to continue on this level, an attempt to justify your claim that parallel information cannot be represented digitally would be in order, but I've seen nothing of the sort. As such, I've asked for examples of things that humans can remember that digital logic cannot, keeping in mind my many qualifiers that have gone undisputed. One will do.

I'd say shifting from arguments ad hominem to arguments from authority, when you fail to engage the subject directly, shows ignorance. Lifting dubious quotes from Google and then basing your [non-]argument on obviously spurious "facts" shows ignorance. Refusing to either refute my positions (without strawmen like "momic the human brain" with implications beyond storage that mislead the reader), or provide evidence for your position, shows ignorance.

But as O'Reilly says, we'll let the audience decide.

Skillery, obviously that doesn't help much. It sounds somewhat compatible with the notion of subatomic particles carrying intelligence a la philotes, but I don't think even a liberal reading can make terms like "refine" and "purify" mean "blast into bits." Who knows.

Has there yet been a claim of where in the brain the spirit/body interaction takes place? Or somewhat equivalently, at what point in the chemical reactions? I admit to only skimming the religion-infused posts...

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Pooka, I was talking to John. Please know for future reference that I don't get snotty until someone asks for it [Smile]

I'm glad you brought up meaning vs. chemistry. This is the hardest and most important question. Is there meaning there intrinsically, or only because we are able to interpret it? If the latter, does that work for any group of observers (human or not)? Neither building really cool computers nor figuring out brain interactions is going to answer questions like these to our satisfaction.

On external readings...Penrose comes off as rather fanciful and defensive. I touched on this when I defended Godel from John's overgeneralizations earlier, but we can revisit him if there's some subtopic you find interesting.

What part of the quantum vs. relativity information did you find relevant? (I'm not going to criticize the pop-sci literature ATM -- not because it doesn't deserve it, but because there's nothing better to link to; the position of more educated sources is largely "we have no idea.")

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Other posts of note after I stopped:

(MrSquicky)
mack,
You've been doing a great job. Mind if I take over for a little bit? Tag me in baby, I'm ready to go.

pooka,
I've never been terribly interested in the biological basis of behavior (BBBiology as it's called), so don't quote me on this, but I'm pretty sure reflexes, despite being largely autonomic in execution, are generally considered part of the somatic nervous system. Of course, that depends on exactly what kinds of reflexing you're talking about.

I think mack filled in the basics for what I'm going to say. If I use a term or concept that is unfamiliar, be sure to point it out and I'll clarify.

The kind of stereotypical reflex arc is the sensory nerve to afferent interneuron to the spinal cord then immediately back out on an efferent interneuron to a muscular nerve. While the sensation may travel up the spinal cord as sensation to be processed in the brain, the reflex arc doesn't involve this and generally comes out faster. That's why you pull your hand away before you realize that something is hot.

There are other reflexes that control the funcioning of internal organs and not muscular reponses. For example, the Mamalian diving reflex, where a shock of extremely cold water to a person's face can trigger a massive activation of the parasympathetic nervous system, thus putting the body into a sort of dratic slow down.

skillery,
You asked a little while ago about brain storage. Leto (John L) answered with a lot of hostility and a generous helping of poor information, as is his wont. Seriously John, where did you get the information that neurons store memory in the nuclei? That's utter BS. If you're going to bitch about people not knowing things, you really should actually know the basics of the field before jumping in with fists flailing.

Anyway, skillz, it's important to realize that the brain and a computer store information much differently. A computer relies on on/off states of either magnetized little bits of stuff or a flow/no-flow of electricity. The brain doesn't have the option of that sort of permenant store, but it does have a much more complex way of doing things. Nerves store information and govern actions based on a complex set of interconnections between themselves. It's not the nerve cells themselves, but rather the network that they form that allows the complexities of life.

Mack talked about how the nerve impulse travels down on cell and is transferred to another cell, but she hadn't yet gotten into how the nervous systems acts as a network. At either end of a nerve cell, there can be many, many branches off for (at the in end) receiving neurotransmitters or (at the out end) setting off neurotransmitters. In many cells, there are literally hundreds of these branches (called dendrites at the receiving end and terminal endings - yeah, I know, it's redundantly unecessary - at the transmitting ones). Each one of those dendrites or terminal endings can be tasked to a separate nerve cell, or some of them can affect the same cell, or they can even branch back onto the same cell that sent them, so a cell firing shoots a message out some of its endings onto its dendrites.

Now, mack covered this, but I'm going to restate it because it's really important to understand it. When an impulse hits a dendrite, bits of neurotransmitter are packed up in vesicles and shoved out into the synaptic cleft where the vesicles burst and they travel across the gap. When they reach the other side, they attach themselves to specialized receptors and cause changes in the post-synaptic nerve cell. The changes can either be activating the cell, thus bringing it closer firing or crossing the threshold and making it fire or depressing the cell, thus moving it further away from firing.

So, in some cases, you'll have a nerve cell linked multiple times to another nerve cell and some of these links are excititory and some of them are inhibitory. Freaky, isn't it. That's actually works because the can be modulated based on context.

Now, a nerve can only fire or not fire. That's the only information it can carry. There's no "this is pain-firing" and a separate "this is pleasure-firing". To carry that information, you need different nerve paths. A cell in the pain pathway, however, can either be transmitting it's information leading to a sensation of pain, or it can be not transmitting, leading to the absence of a perception of pain.

Also, that post-synapitc cell that we were talking about that's getting contradictory messages from the other cell is also getting messages from all these other cells as well. As I said, there can be literally hundreds of other cells pinging away it. In most complex pathways, there will need to be multiple cells exiting another cell before it will fire. So, the pain path cell might itself fire, but the next cell in the pain path might be being inhibited by a bunch of other cells or at least not being stimulated enough to fire, and the nerve impulse will end there and there will be no perception of pain.

A possible problem with the all-or-none law of nerve firing is that it doesn't seem to account for stimuli of different intensities, unless you're going to have a bunch of largely redundant pathways all hitting the target at the same time. Instead of using such a wasteful system, our nervous system uses temporal summation. It's how often in a period of time that a neuron fires that determines how intense a stimulus is perceived. This is achieved by a neat little process that happens in a neuron after it fires. There's a period of time where it can't fire again no matter what, called the refractory period. After that, there's a period where the cell is harder to get to fire that eventually diminishes when it gets back to its resting state. So, instead of hitting it with 10 thingies, for a while you need 15, then 14, then 13, etc. until it gets back to 10.

Another factor to consider is the different chemical states that there can be. The body sends messages by nerve impulses but it also uses hormones generally traveling through the blood stream to send other messages. In various ways, these chemicals can alter how the neurotransmitter stuff works. So in the case above, where we had the contradictory exciting and inhibiting messages, let's say they are being carried by different neurotransmitter. If we introduce a chemical to, let's say, block the majority of sites where one of the neurotransmitters binds to the post-synaptic cell, then it's influence is going to be blockes as well. Or let's say the chemical makes the one NT to be cleaned up sooner than it normally would be while the other one will hang around longer (that's the reuptake inhibitor in Selective Serotonin Reuptake Inhibitors or SSRI's) than the one message is going to hang around longer than the other one.

It's amazing how much complexity that these arangements can make possible in even a very simple insect or something. For example, the stereotyped walking behavoir or many species (our own included, to a certain extent) is due to Central Pattern Generators or CPGs. These are more or less perpetual motion mechaines made up of neurons. Once they get started from the outside, they cells in the pattern stimulate themelves in a circle, with each part of the circle bringing out a different part of the walking cycle. Dump say a fear hormone into the mix, and the cycling is sped up, leading to faster motion.

Anyway, that's the very basics of how neurons work in a networked fashion. I would like to point out that, from my perspective, I'd characterize my knowledge of that side of psychology as me knowing a very little bit. There's an immense body of knowledge that I just don't know about nor am particulary interested in. I just know the basics.




Oh, and I wanted to throw out another neat piece of information. A nerve cell that fires, barring other changes, becomes infitessimily more likely to fire again. Over time, this results in a process called long term potentiation, by which an often used nerve path way sort of becomes smoother, more likely to fire at lower stimulations. I haven't really studying this out at all, but I think that the possibilties for things springing from this are kind of neat.

(fugu)
To reiterate for Richard, Godel's incompleteness theorem poses no problem at all for AI. Hofstadter himself explained why in one of his books.

The part/consequence of Godel's theorem that people think "causes problems" for machines is the idea that one can feed a machine a problem which is the equivalent of "this machine cannot prove this statement true". Which is true, but can never be proven true by the machine (for certain limited definitions of proof).

However, I dare any person to prove the statement (or an equivalent one) "[your name] cannot prove this statement true". Equally impossible. So Godels incompleteness theorem is, in this way, no more or less a barrier to machines than to people.

(ssywak)
Apologies for my trollishness. I've got to work at correcting that aspect of myself & my supposed debating skillz.

Amka,

But what if the God a perticular person has chosen is not the true God. What is "Person X" has chosen to believe in a God that does not exist. What if it's some other God that exists.

What if "Person X" is a Jew, or a Jehovah's Witness, or a Muslim, or you? What if none of us have it right?

Everyone thinks that their own way is right--that they belong to the "One True Church" (or, in my case, the "One True Un-Church.") Whatever scientific test we're proposing here would need to be able to discriminate among different possible types of God and Spirit. What if you can have spirit, but there is no central intelligence and mechanism of action for God?

Ami, I realize that the existence/non-existence of a human soul has an immense impact on my life. That's why I spend so much damned time looking for it, and why I get so pissed off when no one has any idea what it is, or how to find/detect it. I've been having this debate since at least High-School, and I feel that I've been pretty open and fair about it. I'll listen to Lewis, and to what's-his-name trying to prove Darwin a fool, and challenge my beliefs at every opportunity. I acknowledge that I think there's something "inside me" that's more than just a series of wonderfully complicated chemical reactions. But I can't put a name to it, and I can't seem to just wrap it up in the concept of Soul, and God, and all that. What if it's just "awareness?" What if we have memory--maybe better, maybe worse than the other animals in the universe--coupled with a stronger sense of "self-awareness?" There may be no individual, innate "self" (Steve as different from Ami on some core level), but only my memories instead of yours, being reviewed by some kernel of awareness that all animals possess in varying degrees.

Again, when I watched the chemical processes in my mother's brain falter--and with them her personality--this last interpretation was really driven home. We are meat. But we are aware. That makes us semi-unique on the planet. It makes humankind, as a species, worth preserving and advancing.

But God and the Soul either have nothing to do with it, or do not need to have anything to do with it to give it its innate value.

Xaos,

Philosophy gives us the language to discuss things, but has it ever proven anything? It allows us to construct things (such as political systems), and as it gets a touch more scientific (the study of logic, for instance) it helps us with the physical sciences. It's certainly part of the path towards knowledge, but I believe that it always winds up deferring to the physical sciences for the last 100 feet or so.

(MrSquicky)
Leto,
Your decriptions of "facts" on this thread have been a mixture of some facts, some assertions of highly debating theories as fact, and some egregious BS that I can only assume you've made up because you've certainly never gotten it from a reliable source. As I've said before, I'd never dream that it was possible for you to either admit you were wrong or even act responsibily, but I think that it's important that people understand how unworthy of trust you are.

You want to play the bully and make up for your ignorance with bluster, that's fine. Go do it somewhere else, or at least choose a topic that I don't know anything about. We don't need you if you're going to be like this, and, as much as this may suprise you, I'm not at all intimidated by you.

(Bob the Lawyer)
I don?t understand why people have been going into such detail about the nervous system and ignoring things like the limbic system and the differences between things like short term memory, working memory and long term memory. You know, things like how they?re formed, how one becomes the other, etc. Basically, why people aren?t answering the questions about the brain and rather are going into big long spiels about the inner workings of nerves when you really don?t need to understand how reflexes work to get a basic understanding of how memory storage works.

I assumed it was just a pissing contest. Hell, I know I answered pooka?s questions because a) she asked and b) I got to look smart. But at least I?m honest about my motivations [Wink]

(Xaposert)
That is a tricky question because of philosophy's rather unique desire to question every possible assumption. Whereas most other fields have starting assumptions from which to base proofs upon and frame debates, philosophy does not, except perhaps for logic itself. As a result, although I think philosophy does prove things, there is tends to always be someone there to question the premises of the proof ad infinitum. For instance, I think philosophy has proven (as far as your typical proof for something can go) that we exist - despite the fact that some still doubt it.

Aside from things like that, there's also more practical philosophical proofs that have spun off into various fields. (Whenever philosophy becomes practical, this seems to happen.) The field of mathematics, for instance, originated as a set of philosophical proofs that became their own field once the proofs became widely accepted and studied.

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