I'm not sure which side to come down on here. To the best of my knowledge most (real) programming languages are Turing complete. The should, logically, have equal power.
However, languages differ so radically in expressiveness that I often have to remind myself about Turing. To take a classic example, Lisp allows you write functions that return functions, and to define functions within other functions. C allows neither. (Though people don't give function pointers enough credit.) Logically this shouldn't make any difference on an abstract reading of programming; you can certainly get the same results in either language. But it very definitely does affect how you program and think about programming.
Why is this relevant? As I wrote that it occurred to me that this may reflect on state of human languages. Lisp and C are like night and day, and there are things that can be expressed in Lisp that are simply impossible in C. However, we know that the languages are have equivalent expressive power; they are both equally Turning complete. So the apparent difference in their power is just that, an apparent difference. Practically speaking, Lisp hackers don't think about programming in the same was as C hackers, but is a statement about the hackers, not computing, or programming.
So, my question is, can we extend this analogy to human languages? Could all human languages be effectively equal in expressiveness, but the apparent differences so dense as to mask this fact? The barrier would not that the languages are unequal but that our view of how we use them is distorted, that that view does not reflect the facts of the language. Unique syntax conflicting with identical semantics and all that.
I realize I'm dangerously close to the point where people begin taking their analogies literally, but given the focus on computing in cogsci it seems inevitable that this question would come up eventually. (In other words, it's not my fault, cogsci made me do it!;-)
that the realm of philosophy is those areas that haven't proven amenable to scientific investigation
Hmm, that's not actually what I was thinking. I'm not sure if I would even draw a line between the two, considering how fluid science has become, and how 'scientific' philosophy has become. Psychology, after all, is barely even a science if we take physics as a prototype, and physics itself is becoming more like a branch of philosophy all the time. (Witness quantum mechanics, which was formulated as an epistemological theory.) It might be more rewarding to place philosophy in the same catagory as mathematics, hovering between science and the arts, but serving as a backbone for the former (and in this case, the latter as well).
a statement ammenable to scientific proof
Agreed. To the best of my knowledge, cogpsy and linguistics supports that intuition as well--there are certainly statements that can be made in, e.g., Japanese, that I'll never be able to fully comprehend, or even begin to understand. On top of that, language almost certainly can't be formalized, so we can expect it to remain a 'dirty' field. This is not to say that one couldn't come up with a crufty-but-workable way of translating the term, though.
the theory that language and thought are a one-to-one transformation.
Once again I agree. Taking the Language of Thought literally would simply be insane, and is a position that, AFAIK, is very unpopular.
Circling back around to the beginning of this thread, while I agree that language restricts what can be expressed and, because language is so intwined with thought, what one can think about easily, I don't believe it follows that there are thoughts that people in culture A can have that those in culture B cannot simply because their languages are different. (Hopefully B can't express "run-on sentence" either.;-) Culture B may have a helluva time wrapping their brains around A's subtle ganulations of social-emotional states (to pick an example at random), but I don't believe we can a priori comclude than B can't experience subtle social emotions. They may not even realise they can--sinse they lack the concept with which to express their experience--but it doesn't seem contradictory to say that they can still have those thoughts.
OTOH, the opposite doesn't seem contradictory either. Time to call in the scientists, methinks.
Scheme is a neat little rendition of Lisp that, while better than many more popular languages, simply cannot match the power of 'real' Lisp. (IMO, of course.) While I'm happier with it than, say, C++, I would be very upset if it became the de facto Lisp in the world. Using the names synonymously just adds to the problem.
I was wondering when someone would point that out.
I use Windows for my dialup, because my Unix boxen don't like my ISP and my family doesn't like Unix. The comment was most aimed at the resulting quoting problem.
As for philosophy, to be honest you'd have to have suffered some severe head trauma to believe that philosphy can hold a monopoly on the mind. It most certainly can contribute a great deal--that is, in fact, my job at the moment--but we have to make room for neuroscience and psychology (the latter having been a branch of philosophy until recently, if that makes you feel better). The result of this cooperation is progress, both in science and philosophy; progress which, for some reason, seems to disturb some philosophers. I am not one of them, however, and I stand by my statement.
I was a bit suprised by that one as well. But then I realised that I should be happy that he actually mentioned Lisp, even negatively; AFAICT, most programmer's understanding of the Lisp stops at the parenthesis, and even then they assume it's Scheme (or "that scripting language").
I'm sure that one day Lisp will once again be recognized for all that it is (hurry up TUNES;-), but until then it will cast aside as a research project in the minds of most Real World Prgrammers.
No, it's a cognitive science question, and a fairly important one at that. Cognitive linguistics and psychology posed the question and provided the answer. The days of philosophy's monopoly over the mind are long past, and philosophy is better because of it.
Er, I don't see any claims about creationism at all in his post. He simply stated that evolution is a theory, and that very often its less intelligent defenders accept it as an absolutely proven--and sometimes undisprovable--fact, and use its 'facthood' as fuel to burn creationists. You note, as well, that he qualified 'evolution' with "in the sense of creation", which, I believe, is a reference to the origin of life, not what how life turned into humans. Strictly speaking that probably isn't part of evolution, but again the cognitively challenged tend to assume that it is not only a necessary part of evolutionary theory, but that it has somehow been proven (without being able to say just what was proven, of course).
I believe very strongly that evolution is true--it has been sufficiently proven for me. I also believe that chemistry is sufficient to explain the appearance of life. I do not, however, believe that the either is a fact; to the best of my knowledge the latter doesn't even have a complete theory to work with, let alone the evidence required for facthood. They are likely, the former very much so, but that is all. IMO, to think otherwise would be a serious breach of one's scientific integrity. But I suppose that belief just makes me look silly, eh AC?
The Marathon Trilogy had, IMNSHO, the greatest story line of any game I've played. I'm not going to claim that it's Hugo-quality SF, but it's the only game that I still go back to after four years just so I can read the terminals and try to piece together the remaining mysteries. It's certainly the only game I play solely for the story. (As well as the only reason I'll touch a Mac these days.)
And I'm not the only one. The Story Page has spent the last three years or so disassembling the storyline, the secrets and mysteries and trying to figure out just what was happening while we were punching our way through hoards of Pfhor. (Literally punching in some cases.) Several hundred MBs (!) later we're now diving through the source looking for comments that may shed some light of an interpretation of garbled text we've been mulling over for two years. Marathon fans are dedicated, to say the least (in the least insulting way;-).
And for those who think that Marathon is long past, just a Mac game from the Doom era that a handful of the obsessed are keeping alive, why don't you stop by the Story Page and grep for "Halo". Consider it backstory.
(This little bit of insight into the Marathon fanboy mind, such as it is, was brought to you the number 7 and the letter Durandal. Beginning mocking...now.)
Sure, I can't see any reason why an artificial eye wouldn't work. Artificial retinas seem to be comming along nicely (better than Jerry's rig, anyway), and they operate just as you say, by signalling to the LGN via the optic nerve. OTOH, we're still at least a decade away from even something as simple as a good 1024x1024 greyscale, let alone the retina's 10000000x10000000x24 or so.
However, my point is that this has little to do with how vision, let alone any other sense, works. What we have is a method for encoding bitmaps with just enough similarity to the retina that the subject can see something; we're at the leading edge of understanding trivially complex, if important, aspect of visual processing. blakestah was correct: it is ludicrous to think we can do what you're proposing with our current technology and understanding of the brain. We're still in the 'if I press here do you see something?' stage of neuroprosthesis, and decades, at the very least, from actually being able to restore sight.
No, that was more a matter of choosing a (relatively) easy target. The catcam pulls data from the LGN (IIRC), which basically maintains a 1:1 mapping with the retina. The data being pulled from the LGN's output (it was output, wasn't it?) to the Primary Visual Cortex will be mostly identical to the the output from the retina to the LGN. So, except for the geography involved, you basically have a very complicated artificial retina for your computer.
Actual vision--what people experience as sight--is far trickier than this, involving far more processing. (Complexity analogy: the catcam-level as a $200 camera plugged into a $2 million dollar supercomputer. Understanding the camera will not necessarily help you understand how the computer recognizes your face and says hi, though it is certainly a start.)
But they don't claim that the cortex is idle, they are just focusing their effort elsewhere.
*shrug* True enough, and I agree.
They prove beyond doubt that retinal inputs arrive at the PVC largely unaltered by the subcortex.
"Largely" is all I need. Once again, I said it is preprocessing, not full cortex (or even LGN) quality processing. Preprocessing of some sort is required simply to get the information packaged for transmission to the LGN (as I believe was mentioned in one of the links above).
It must be inferred that the LGN adds information to the retinal signal rather than replacing it with something completely different.
Agreed. However, if you go back an read my posts--as I've just done--I never said anything to the contrary. (Well, except in my first post, where I accidentally ommited the PVC and simply refered to 'cortex processing' instead of 'SVC porocessing' and 'temporal lobe' processing.) This little war started when you said the cortex has a direct connection to the retina.
(i) QED means "that which is proven" while consciousness is not amenable to normal standards of proof even in humans;
True enough, mostly. However, you can make a case for using behavior to discern whether a subject is conscious (e.g. blindsighted people behave differently than either blind or normal people). Such research has been done of reptiles, as reported in, I believe Science News a few months ago.
to define consciousness broadly enough to encompass mental states in both humans and sea slugs would render the term practically useless.
Which is why I don't. Unfortunately, no one, myself included, makes their definition clear at the outset. I define consciousness as being almost synonymous with experience, that is, possessing qualia. I say "almost" because I tend to follow Whitehead in the details.
That said, I have seen no reason why lower mammals, reptiles, and birds, can't be conscious. In fact, if Panksepp and Watt are correct--expirimentally correct, not simply theoretically--then reptiles mark the emergence of consciousness.
They also fail to react physically in any manner which requires conscious assessment or determination.
Yes, I know this. You could save a lot space if you stopping stating things we both know.
To claim that blindfield vision is conscious in such cases therefore implies a completely isolated visual consciousness incapable of affecting anything else except via the subconscious.
No, you've got it backwards. I said it implies a compartmentalized introspective consciousness, one that is lacking information-rich connections beyond the cortex. The blinsighted subjects may be lacking an ability to introspect consciously, while still being able to have 'external' conscious experiences.
It's plausible to speak of multiple indpendent consciousnesses in subjects with severed corpus callosum; at least each hemisphere is well-equipped enough to constitute a complete independent consciousness.
Yikes, I'd really hate to wander down this path as well. I'll just say that some people consider 'plausible' a stretch.
Now, I finally checked my collection of JCS and found the issue I was looking for: April 1999 is devoted to the self. The lead article discusses the problems with relying on patient testimony for determining consciousness, the possibility of two compartmentalized consciousnesses (oriented inward and outward), and the affects of blindsight and whether it really is blind. Roughly, sinse I'm not going to read it at the moment, people's behavior, abilities, etc, change drastically when they are asked to report about them, vs. when they are simply using them. Tapping your example, a person with a severed corpus callosum may be indistinguishable from a normal person when they simply going about their business, but manifest the split brain effects in the lab and be completely unable to perform tasks they do regularly in the normal life. The problem is that their introspective consciousness--their ability to consciously processes their internal mental states--has been damaged. When they don't attempt to use it, as when they're driving, walking, etc, they're fine.
BTW, JCS is a lot of fun and I dip into it regularly, but it's not the most serious publication. Consciousness studies are still mainly empty philosophising notwithstanding Crick's efforts.
Speaking as a (semi)professional philosopher, and JCS subscriber, I should probably be insulted. Unfortunately, I can't think of any good argument against your statement.
I certainly value my own objective (if undereducated) opinion this much:
I assume that was a typo, but it seems to sum up the problem here. You keep assuming that your opinion has the validity of objective fact, to the extent that you will deny any and all evidence I present. I am certainly not immune to this, but I have attempted to refer to sources (whether on the Web or in print) whenever possible. That you refuse to accept any of them does not speak well of your 'skepticism' and 'broad view'.
I beseech you to go back and have another look at those LGN studies, and consider: what if they just meant that the LGN added extra high-level information to an existing complete retinal map headed for the PVC? And going further, what if they were even mistaken about that, the ascending pathways remain clean and the high-level information generated in the LGN only goes to afferent subcortical destinations? Would their observations still make sense?
This is ridiculous. Are you so unwilling to lose this argument that you would actually claim that every description of the visual system I've found (there were many I didn't include above) is wrong? Look at the last link I tossed re: the LGN (labeled "This"). That is an anatomical description of the visual paths from the retina. Not a theory, nor a proposal for research. A simple description of what connections exist, and where they go. Skepticism is one thing, but you're bordering outright solipsism.
Following that last post, I decided that instead of continuing this flamewar indefinately, I'd actually do some quick research on the web. The following is what I pulled off the first few pages of Yahoo! and Hotbot when I searched for "LGN cortex".
Here: "The LGN organizes inputs from the retina, and slows them down before sending signals to the ocipital lobe (the visual cortex)."
Here: "Incoming sensory signals are not simply relayed to the cerebral cortex. Instead, these afferent signals are first actively gated and modified in the thalamus. Our research is focused on understanding the modulation of visual signals in the lateral geniculate nucleus (LGN), the thalamic station in the pathway that subserves conscious visual perception. The LGN presents a single locus where vision, in a broad sense, can be impacted economically before visual signals are disseminated throughout the cortex. All subsequent cortical processing depends critically upon the nature of the signals that are conveyed by the LGN."
Here: "...to learn how information transmission from the retina to the visual cortex through the LGN is controlled."
This shows the information pathways involved in visual processing: retina-Pretectal area, retina-Superior Colliculus, retina-LGN and LGN-cortex.
There were others, but Netscape crashed (naturally) and I don't want to restep the entire search process.
Retina: I meant to check for info on retinal processing, but the search engines are clogged with retina simulators and other unhelpful pages. But I did find this which mentions the preprocessing of which I was speaking in my first post.
As far as I'm concerned retinal processing is quite low-level.
Agreed. This is part of the reason I referred to it as pre-processing.
There may be motion detection built in but this is most likely used only by subcortical pathways since the cortex also has motion detection of its own.
And why do you think this? Is it so improbable that the cortex would start with the retina's mild processing and improve upon it?
They all pass by the thalamus, but the former two (at least) continue all the way to the cortex.
I'm going to say this again, slowly: I seen have no evidence that, if the retina does in fact perform some pre-processing, there is any way for unprocessed information to get to the brain.
If there is any retinal processing, it's not important for cortical vision.
Again, justify this statement.
Reciting the names of your heroes, even if they are right (and many of the claims they make are pure speculation) doesn't mean that you have understood them correctly.
This is what I mean about being a pretentious ass. Those were the books I happened to have in front of me at the moment. I never said I agreed with them completely, or even mostly, but simply that there statements contradict your own. To be honest, I think Crick is wrong, and Churchland is a looney, but that doesn't mean they can't report empirical results. And until you can provide some references or credentials, they're opinions far outweigh yours.
However that doesn't imply that this is the only role of the thalamus, doesn't imply that the cortical connections originating from the thalamus are more numerous or more important than those originating from the retina, and doesn't imply that that cortical vision doesn't modulate the subconscious visual processing going on in the midbrain.
Of course. As I said, I believe Crick is quite wrong about the thalamus. That doesn't mean he hasn't provided useful data, though.
What's implausible about that?
Nothing in particular. However, my comment was primarily directed at your comments regarding unnecessarily duplicated processing, both in the retina-cortex and LGN-cortex relationships.
You say that cortical pathways don't make us perceptive.
Reread that. I said they aren't responsible for perception itself, not that they don't perceive, or that they aren't vital for the manor in which we perceive. Animals lacking a cortex can perceive, thus the cortex is not required for perception.
I'd like to see you prove that!
Animals lacking a cortex may be conscious. QED.
I did say that "conscious" vision comes from the cortex, and that's directly proven from studies of people with blindness due to neuropathy or brain injury (eg blindsight, prosopagnosia).
This is actually quite interesting in it's own right. The Journal of Consciousness Studies devoted an issue to the subject of blindsight, which included a few articles proposing that some (stressing some, of course) people afflicted with blindsight may be consciously perceiving, but unable to consciously report it, due to damage to their introspective abilities. (That is, the mechanisms which themselves allow for conscious introspection, whatever they may be, cannot access the visual processing, and thus report that there is none when in fact there is.)
Well, if you remove a human's visual cortex they report no conscious experience of vision, if you remove their auditory cortex they report no conscious experience of hearing, and if you remove their frontal lobes they exhibit no conscious mental activity at all even when their motor areas remain intact.
This is a perfect example of the above. Assuming you left enough of their cortex intact for them to report anything, you would collide the possibility that they simply can't express what they are perceiving. It could be that, for example, they are consciously seeing, in a loose sense of the term, via subcortical routes, but cannot say so since their linguistic processing is entirely encapsulated. The cortically based systems used for language are designed to accept sensory input from the cortical sensory systems, and in their absence assume there is none.
But the immense flexibility and power of the cortex in Calvin's model should not be discounted.
Reciting they name of your hero, even if you have understood him correctly, does not mean he is right. You have made several statements along the lines of "there is no room for doubt" and "this has been proven", yet you seem utterly unable to provide any references beyond Calvin. Disagree with those I named all you'd like--though you've apparently never read them, so I can hardly take such criticisms seriously--but at least I provided some sources to support my case. Since you are either unwilling or unable to do so yourself, I shall consider this conversation closed. If you like, you can pretend you won.
First off, I resent the patronizing tone of your post; there have been truly enormous flame wars started by less insulting comments than your own. With that in mind, I have temporally disabled my tact module.
This preprocessed information only goes directly to the old subcortical vision systems.
There seems to be some severe misunderstanding here. If information is processed by the retina, I fail to see where this unprocessed information you refer to would originate. Are you implying that there are two parallel circuits originating on the upper layers of the retina? If the information has been processed before it reaches the optic nerve (i.e., by the retina), how does this unprocessed information arrive at the cortex?
You imply that the visual cortex gets all or most of its input from the LGN. You have it completely wrong I'm afraid. There isn't any room for doubt about this...
Having just scanned through every neuroscience text I could my hands on, I'd say there is considerable room for doubt. Churchland, Crick and Koch (to begin with) all seem agree that the LGN has rich upward connections to the cortex in all mammals, while making little or no reference to any other pathways.
(BTW, have you considered how implausible your explanation is from an evolutionary standpoint?)
...an entirely separate issue from the conscious vision I was talking about in my previous post.
This is an immensely ironic statement. See my closing.
And, as we all know, these cortical pathways are the ones that make us intelligent, perceptive - and, dare I say it - conscious.
True, false and false, respectively.
(Snipping the lecture on the LGN....)
In other words, these bandwidth-limited ascending pathways represent a pretty trifling quantity of information passed on to the visual cortex from the LGN.
Oh, yes, that's the only possible explanation....
Well, what can I say? Cortex roolz! It's what makes us human.
*sigh*
Seriously, it's obvious that you're fairly well read but you have to careful not to identify too closely with certain researchers' narrow preoccupation's.
As opposed to you, who thoughtfully provided one reference to back his argument, and, ironically enough, a researcher who is 'preoccupied' spinal and cerebellar neurons.
As for the rest about the cortex, I would strongly suggest you read: Panksepp's Affective Neuroscience; virtually anything by Crick, Koch; Newman and Baars re. the ERTAS; Damasio as referenced by Calvin; anything by Doug Watt; or the papers here or at the ASSC's online conference about emotion before lecturing about the function of subcortical systems. (Good starting hints: your assessment interaction of emotion and sensory information is 180 degrees from the truth, and consciousness is not a cortical function.)
Nope, he's right, and you left out everything below the cerebrum.
The retina has some significant processing power of it's own--in fact, it is often used as a benchmark for measuring the brain's overall processing capabilities (wrongly, IMO, but that's not relevant). Both edge and movement detection are performed in the rear-most layer of the retina as a pre-processing step before the information is moved up the optic nerve.
The optic nerve feeds into the LGN (the expanded form of which is difficult to spell), which performs a great deal of processing in it's own right--it was, after all, the primary visual system for millions of years--including further (much more refined) edge and movement detection, some object recognition, attention, etc.
The result of that is forwarded to the cortex for the final processing we all know and love, which extends the capabilities of the retina and LGN greatly. However, by that stage the input has virtually no resemblance to the output from the retina, having been thoroughly digested by the lower visual systems. (One further interesting tidbit: the descending pathways, from the cortex to the LGN, have 10x the capacity of the ascending pathways. Make of that what you will.)
(Incidentally, there are a number of us who are trying to combat cerebral chauvinism in neuroscience, and you aren't helping;-)
I believe I remember it too, so you aren't imagine things. IIRC correctly, the retina's has around a millions cells, which would be equivelant to about half as many pixels (since a pixel incorporates the abilities of both a rod and a cone--er, or several rods and cones). The scanning (nuts, forgot the word) makes up for quite a bit, as does the processing capabilities of the tissue itself.
Which brings up the larger problem, IMO: the retina has some non-trivial image processing abilities, and AFAIK none of these implants go beyond simple light sensitive plates. To restore natural vision you'd need the replicate the entire million (IIRC) retinal cells, plus take some very tiny embedded processors in behind them (or to be biologically plausible, build the processors into the light detectors). These are relatively important functions, like edge and movement detection, that I don't believe it would be wise to leave out.
I can think of at least three things wrong with this.
(1) I seen it stated that they aren't in the news.
(2) Intelligence test are 'questionable' measures of, um, anything (witness a recent Science News article explaining why inner city blacks score something like 20 points lower when the test is called and 'intelligence' test, but otherwise do quite normally). Moreso sinse they've only existed for ~90 years, and have only been really accurate for the last few decades, AFAIK. Difficult to say anything globally when 99.99...% of the population has never had an opportunity to take even a poor test.
(3) Given that most people, globally, are living essentially as they're ancestors (sp?) did several centuries ago (and occasionally, worse), the only possible explanation for this would be genetic, and I can assure you, that isn't it.
I agree, although I have a slightly different take on it. People probably aren't any dumber than before, but we should be smarter: we've had a few centuries of devotion to helping the common man, universal education, and all. The result? Nothing. Half the planet is still in the 12th Century, and other half would be if they didn't have to go to High School to get a job at McD's. Excellent progress.
Pepper gas != pepper spray. I apologize for assuming the correct terminology would be used, or that people would know what a 'spray' is.
Incidentally, the Fox story was considerably older than the CNN story; IIRC, from several hours before any statement had been made by the police, while it was happening. They can be forgiven for not wanting to sample the gas to see what it was.
Who would you rather believe; CNN, or Fox News?
I can't believe you seriously asked that; I'm relying on KIRO at the moment. However, given the choice between CNN and Fox--having watched the coverage from both--Fox is well ahead at this point.
-J, who would like to be home in Seattle, but is trapped in Oregon (the riot capital of the NW!).
I'll say this slowly: Fox News says the cops are using tear gas. They also have video of big clouds of what doesn't look much like pepper spray, coming out of grenades the cops are tossing. It just might be that they're using both, eh?
Slashdot Mirror
I'm not sure which side to come down on here. To the best of my knowledge most (real) programming languages are Turing complete. The should, logically, have equal power.
;-)
However, languages differ so radically in expressiveness that I often have to remind myself about Turing. To take a classic example, Lisp allows you write functions that return functions, and to define functions within other functions. C allows neither. (Though people don't give function pointers enough credit.) Logically this shouldn't make any difference on an abstract reading of programming; you can certainly get the same results in either language. But it very definitely does affect how you program and think about programming.
Why is this relevant? As I wrote that it occurred to me that this may reflect on state of human languages. Lisp and C are like night and day, and there are things that can be expressed in Lisp that are simply impossible in C. However, we know that the languages are have equivalent expressive power; they are both equally Turning complete. So the apparent difference in their power is just that, an apparent difference. Practically speaking, Lisp hackers don't think about programming in the same was as C hackers, but is a statement about the hackers, not computing, or programming.
So, my question is, can we extend this analogy to human languages? Could all human languages be effectively equal in expressiveness, but the apparent differences so dense as to mask this fact? The barrier would not that the languages are unequal but that our view of how we use them is distorted, that that view does not reflect the facts of the language. Unique syntax conflicting with identical semantics and all that.
I realize I'm dangerously close to the point where people begin taking their analogies literally, but given the focus on computing in cogsci it seems inevitable that this question would come up eventually. (In other words, it's not my fault, cogsci made me do it!
that the realm of philosophy is those areas that haven't proven amenable to scientific investigation
;-) Culture B may have a helluva time wrapping their brains around A's subtle ganulations of social-emotional states (to pick an example at random), but I don't believe we can a priori comclude than B can't experience subtle social emotions. They may not even realise they can--sinse they lack the concept with which to express their experience--but it doesn't seem contradictory to say that they can still have those thoughts.
Hmm, that's not actually what I was thinking. I'm not sure if I would even draw a line between the two, considering how fluid science has become, and how 'scientific' philosophy has become. Psychology, after all, is barely even a science if we take physics as a prototype, and physics itself is becoming more like a branch of philosophy all the time. (Witness quantum mechanics, which was formulated as an epistemological theory.) It might be more rewarding to place philosophy in the same catagory as mathematics, hovering between science and the arts, but serving as a backbone for the former (and in this case, the latter as well).
a statement ammenable to scientific proof
Agreed. To the best of my knowledge, cogpsy and linguistics supports that intuition as well--there are certainly statements that can be made in, e.g., Japanese, that I'll never be able to fully comprehend, or even begin to understand. On top of that, language almost certainly can't be formalized, so we can expect it to remain a 'dirty' field. This is not to say that one couldn't come up with a crufty-but-workable way of translating the term, though.
the theory that language and thought are a one-to-one transformation.
Once again I agree. Taking the Language of Thought literally would simply be insane, and is a position that, AFAIK, is very unpopular.
Circling back around to the beginning of this thread, while I agree that language restricts what can be expressed and, because language is so intwined with thought, what one can think about easily, I don't believe it follows that there are thoughts that people in culture A can have that those in culture B cannot simply because their languages are different. (Hopefully B can't express "run-on sentence" either.
OTOH, the opposite doesn't seem contradictory either. Time to call in the scientists, methinks.
Scheme is a neat little rendition of Lisp that, while better than many more popular languages, simply cannot match the power of 'real' Lisp. (IMO, of course.) While I'm happier with it than, say, C++, I would be very upset if it became the de facto Lisp in the world. Using the names synonymously just adds to the problem.
I was wondering when someone would point that out.
I use Windows for my dialup, because my Unix boxen don't like my ISP and my family doesn't like Unix. The comment was most aimed at the resulting quoting problem.
As for philosophy, to be honest you'd have to have suffered some severe head trauma to believe that philosphy can hold a monopoly on the mind. It most certainly can contribute a great deal--that is, in fact, my job at the moment--but we have to make room for neuroscience and psychology (the latter having been a branch of philosophy until recently, if that makes you feel better). The result of this cooperation is progress, both in science and philosophy; progress which, for some reason, seems to disturb some philosophers. I am not one of them, however, and I stand by my statement.
I was a bit suprised by that one as well. But then I realised that I should be happy that he actually mentioned Lisp, even negatively; AFAICT, most programmer's understanding of the Lisp stops at the parenthesis, and even then they assume it's Scheme (or "that scripting language").
;-), but until then it will cast aside as a research project in the minds of most Real World Prgrammers.
I'm sure that one day Lisp will once again be recognized for all that it is (hurry up TUNES
No, it's a cognitive science question, and a fairly important one at that. Cognitive linguistics and psychology posed the question and provided the answer. The days of philosophy's monopoly over the mind are long past, and philosophy is better because of it.
Or an oil rig. Someone must have an oil rig they'd be willing to part with. Just think, you could fund the project by selling oil! ;-)
Change "proven" to "proved" where appropriate. I can't believe I typed that.
Er, I don't see any claims about creationism at all in his post. He simply stated that evolution is a theory, and that very often its less intelligent defenders accept it as an absolutely proven--and sometimes undisprovable--fact, and use its 'facthood' as fuel to burn creationists. You note, as well, that he qualified 'evolution' with "in the sense of creation", which, I believe, is a reference to the origin of life, not what how life turned into humans. Strictly speaking that probably isn't part of evolution, but again the cognitively challenged tend to assume that it is not only a necessary part of evolutionary theory, but that it has somehow been proven (without being able to say just what was proven, of course).
I believe very strongly that evolution is true--it has been sufficiently proven for me. I also believe that chemistry is sufficient to explain the appearance of life. I do not, however, believe that the either is a fact; to the best of my knowledge the latter doesn't even have a complete theory to work with, let alone the evidence required for facthood. They are likely, the former very much so, but that is all. IMO, to think otherwise would be a serious breach of one's scientific integrity. But I suppose that belief just makes me look silly, eh AC?
The Marathon Trilogy had, IMNSHO, the greatest story line of any game I've played. I'm not going to claim that it's Hugo-quality SF, but it's the only game that I still go back to after four years just so I can read the terminals and try to piece together the remaining mysteries. It's certainly the only game I play solely for the story. (As well as the only reason I'll touch a Mac these days.)
;-).
And I'm not the only one. The Story Page has spent the last three years or so disassembling the storyline, the secrets and mysteries and trying to figure out just what was happening while we were punching our way through hoards of Pfhor. (Literally punching in some cases.) Several hundred MBs (!) later we're now diving through the source looking for comments that may shed some light of an interpretation of garbled text we've been mulling over for two years. Marathon fans are dedicated, to say the least (in the least insulting way
And for those who think that Marathon is long past, just a Mac game from the Doom era that a handful of the obsessed are keeping alive, why don't you stop by the Story Page and grep for "Halo". Consider it backstory.
(This little bit of insight into the Marathon fanboy mind, such as it is, was brought to you the number 7 and the letter Durandal. Beginning mocking...now.)
Sure, I can't see any reason why an artificial eye wouldn't work. Artificial retinas seem to be comming along nicely (better than Jerry's rig, anyway), and they operate just as you say, by signalling to the LGN via the optic nerve. OTOH, we're still at least a decade away from even something as simple as a good 1024x1024 greyscale, let alone the retina's 10000000x10000000x24 or so.
However, my point is that this has little to do with how vision, let alone any other sense, works. What we have is a method for encoding bitmaps with just enough similarity to the retina that the subject can see something; we're at the leading edge of understanding trivially complex, if important, aspect of visual processing. blakestah was correct: it is ludicrous to think we can do what you're proposing with our current technology and understanding of the brain. We're still in the 'if I press here do you see something?' stage of neuroprosthesis, and decades, at the very least, from actually being able to restore sight.
No, that was more a matter of choosing a (relatively) easy target. The catcam pulls data from the LGN (IIRC), which basically maintains a 1:1 mapping with the retina. The data being pulled from the LGN's output (it was output, wasn't it?) to the Primary Visual Cortex will be mostly identical to the the output from the retina to the LGN. So, except for the geography involved, you basically have a very complicated artificial retina for your computer.
Actual vision--what people experience as sight--is far trickier than this, involving far more processing. (Complexity analogy: the catcam-level as a $200 camera plugged into a $2 million dollar supercomputer. Understanding the camera will not necessarily help you understand how the computer recognizes your face and says hi, though it is certainly a start.)
But they don't claim that the cortex is idle, they are just focusing their effort elsewhere.
*shrug* True enough, and I agree.
They prove beyond doubt that retinal inputs arrive at the PVC largely unaltered by the subcortex.
"Largely" is all I need. Once again, I said it is preprocessing, not full cortex (or even LGN) quality processing. Preprocessing of some sort is required simply to get the information packaged for transmission to the LGN (as I believe was mentioned in one of the links above).
It must be inferred that the LGN adds information to the retinal signal rather than replacing it with something completely different.
Agreed. However, if you go back an read my posts--as I've just done--I never said anything to the contrary. (Well, except in my first post, where I accidentally ommited the PVC and simply refered to 'cortex processing' instead of 'SVC porocessing' and 'temporal lobe' processing.) This little war started when you said the cortex has a direct connection to the retina.
expression of the establishment view?.
But are they?
(i) QED means "that which is proven" while consciousness is not amenable to normal standards of proof even in humans;
True enough, mostly. However, you can make a case for using behavior to discern whether a subject is conscious (e.g. blindsighted people behave differently than either blind or normal people). Such research has been done of reptiles, as reported in, I believe Science News a few months ago.
to define consciousness broadly enough to encompass mental states in both humans and sea slugs would render the term practically useless.
Which is why I don't. Unfortunately, no one, myself included, makes their definition clear at the outset. I define consciousness as being almost synonymous with experience, that is, possessing qualia. I say "almost" because I tend to follow Whitehead in the details.
That said, I have seen no reason why lower mammals, reptiles, and birds, can't be conscious. In fact, if Panksepp and Watt are correct--expirimentally correct, not simply theoretically--then reptiles mark the emergence of consciousness.
They also fail to react physically in any manner which requires conscious assessment or determination.
Yes, I know this. You could save a lot space if you stopping stating things we both know.
To claim that blindfield vision is conscious in such cases therefore implies a completely isolated visual consciousness incapable of affecting anything else except via the subconscious.
No, you've got it backwards. I said it implies a compartmentalized introspective consciousness, one that is lacking information-rich connections beyond the cortex. The blinsighted subjects may be lacking an ability to introspect consciously, while still being able to have 'external' conscious experiences.
It's plausible to speak of multiple indpendent consciousnesses in subjects with severed corpus callosum; at least each hemisphere is well-equipped enough to constitute a complete independent consciousness.
Yikes, I'd really hate to wander down this path as well. I'll just say that some people consider 'plausible' a stretch.
Now, I finally checked my collection of JCS and found the issue I was looking for: April 1999 is devoted to the self. The lead article discusses the problems with relying on patient testimony for determining consciousness, the possibility of two compartmentalized consciousnesses (oriented inward and outward), and the affects of blindsight and whether it really is blind. Roughly, sinse I'm not going to read it at the moment, people's behavior, abilities, etc, change drastically when they are asked to report about them, vs. when they are simply using them. Tapping your example, a person with a severed corpus callosum may be indistinguishable from a normal person when they simply going about their business, but manifest the split brain effects in the lab and be completely unable to perform tasks they do regularly in the normal life. The problem is that their introspective consciousness--their ability to consciously processes their internal mental states--has been damaged. When they don't attempt to use it, as when they're driving, walking, etc, they're fine.
BTW, JCS is a lot of fun and I dip into it regularly, but it's not the most serious publication. Consciousness studies are still mainly empty philosophising notwithstanding Crick's efforts.
Speaking as a (semi)professional philosopher, and JCS subscriber, I should probably be insulted. Unfortunately, I can't think of any good argument against your statement.
I certainly value my own objective (if undereducated) opinion this much:
I assume that was a typo, but it seems to sum up the problem here. You keep assuming that your opinion has the validity of objective fact, to the extent that you will deny any and all evidence I present. I am certainly not immune to this, but I have attempted to refer to sources (whether on the Web or in print) whenever possible. That you refuse to accept any of them does not speak well of your 'skepticism' and 'broad view'.
I beseech you to go back and have another look at those LGN studies, and consider: what if they just meant that the LGN added extra high-level information to an existing complete retinal map headed for the PVC? And going further, what if they were even mistaken about that, the ascending pathways remain clean and the high-level information generated in the LGN only goes to afferent subcortical destinations? Would their observations still make sense?
This is ridiculous. Are you so unwilling to lose this argument that you would actually claim that every description of the visual system I've found (there were many I didn't include above) is wrong? Look at the last link I tossed re: the LGN (labeled "This"). That is an anatomical description of the visual paths from the retina. Not a theory, nor a proposal for research. A simple description of what connections exist, and where they go. Skepticism is one thing, but you're bordering outright solipsism.
Following that last post, I decided that instead of continuing this flamewar indefinately, I'd actually do some quick research on the web. The following is what I pulled off the first few pages of Yahoo! and Hotbot when I searched for "LGN cortex".
Here: "The LGN organizes inputs from the retina, and slows them down before sending signals to the ocipital lobe (the visual cortex)."
Here: "Incoming sensory signals are not simply relayed to the cerebral cortex. Instead, these afferent signals are first actively gated and modified in the thalamus. Our research is focused on understanding the modulation of visual signals in the lateral geniculate nucleus (LGN), the thalamic station in the pathway that subserves conscious visual perception. The LGN presents a single locus where vision, in a broad sense, can be impacted economically before visual signals are disseminated throughout the cortex. All subsequent cortical processing depends critically upon the nature of the signals that are conveyed by the LGN."
Here: "...to learn how information transmission from the retina to the visual cortex through the LGN is controlled."
This shows the information pathways involved in visual processing: retina-Pretectal area, retina-Superior Colliculus, retina-LGN and LGN-cortex.
There were others, but Netscape crashed (naturally) and I don't want to restep the entire search process.
Retina: I meant to check for info on retinal processing, but the search engines are clogged with retina simulators and other unhelpful pages. But I did find this which mentions the preprocessing of which I was speaking in my first post.
As far as I'm concerned retinal processing is quite low-level.
Agreed. This is part of the reason I referred to it as pre-processing.
There may be motion detection built in but this is most likely used only by subcortical pathways since the cortex also has motion detection of its own.
And why do you think this? Is it so improbable that the cortex would start with the retina's mild processing and improve upon it?
They all pass by the thalamus, but the former two (at least) continue all the way to the cortex.
I'm going to say this again, slowly: I seen have no evidence that, if the retina does in fact perform some pre-processing, there is any way for unprocessed information to get to the brain.
If there is any retinal processing, it's not important for cortical vision.
Again, justify this statement.
Reciting the names of your heroes, even if they are right (and many of the claims they make are pure speculation) doesn't mean that you have understood them correctly.
This is what I mean about being a pretentious ass. Those were the books I happened to have in front of me at the moment. I never said I agreed with them completely, or even mostly, but simply that there statements contradict your own. To be honest, I think Crick is wrong, and Churchland is a looney, but that doesn't mean they can't report empirical results. And until you can provide some references or credentials, they're opinions far outweigh yours.
However that doesn't imply that this is the only role of the thalamus, doesn't imply that the cortical connections originating from the thalamus are more numerous or more important than those originating from the retina, and doesn't imply that that cortical vision doesn't modulate the subconscious visual processing going on in the midbrain.
Of course. As I said, I believe Crick is quite wrong about the thalamus. That doesn't mean he hasn't provided useful data, though.
What's implausible about that?
Nothing in particular. However, my comment was primarily directed at your comments regarding unnecessarily duplicated processing, both in the retina-cortex and LGN-cortex relationships.
You say that cortical pathways don't make us perceptive.
Reread that. I said they aren't responsible for perception itself, not that they don't perceive, or that they aren't vital for the manor in which we perceive. Animals lacking a cortex can perceive, thus the cortex is not required for perception.
I'd like to see you prove that!
Animals lacking a cortex may be conscious. QED.
I did say that "conscious" vision comes from the cortex, and that's directly proven from studies of people with blindness due to neuropathy or brain injury (eg blindsight, prosopagnosia).
This is actually quite interesting in it's own right. The Journal of Consciousness Studies devoted an issue to the subject of blindsight, which included a few articles proposing that some (stressing some, of course) people afflicted with blindsight may be consciously perceiving, but unable to consciously report it, due to damage to their introspective abilities. (That is, the mechanisms which themselves allow for conscious introspection, whatever they may be, cannot access the visual processing, and thus report that there is none when in fact there is.)
Well, if you remove a human's visual cortex they report no conscious experience of vision, if you remove their auditory cortex they report no conscious experience of hearing, and if you remove their frontal lobes they exhibit no conscious mental activity at all even when their motor areas remain intact.
This is a perfect example of the above. Assuming you left enough of their cortex intact for them to report anything, you would collide the possibility that they simply can't express what they are perceiving. It could be that, for example, they are consciously seeing, in a loose sense of the term, via subcortical routes, but cannot say so since their linguistic processing is entirely encapsulated. The cortically based systems used for language are designed to accept sensory input from the cortical sensory systems, and in their absence assume there is none.
But the immense flexibility and power of the cortex in Calvin's model should not be discounted.
Reciting they name of your hero, even if you have understood him correctly, does not mean he is right. You have made several statements along the lines of "there is no room for doubt" and "this has been proven", yet you seem utterly unable to provide any references beyond Calvin. Disagree with those I named all you'd like--though you've apparently never read them, so I can hardly take such criticisms seriously--but at least I provided some sources to support my case. Since you are either unwilling or unable to do so yourself, I shall consider this conversation closed. If you like, you can pretend you won.
First off, I resent the patronizing tone of your post; there have been truly enormous flame wars started by less insulting comments than your own. With that in mind, I have temporally disabled my tact module.
...an entirely separate issue from the conscious vision I was talking about in my previous post.
This preprocessed information only goes directly to the old subcortical vision systems.
There seems to be some severe misunderstanding here. If information is processed by the retina, I fail to see where this unprocessed information you refer to would originate. Are you implying that there are two parallel circuits originating on the upper layers of the retina? If the information has been processed before it reaches the optic nerve (i.e., by the retina), how does this unprocessed information arrive at the cortex?
You imply that the visual cortex gets all or most of its input from the LGN. You have it completely wrong I'm afraid. There isn't any room for doubt about this...
Having just scanned through every neuroscience text I could my hands on, I'd say there is considerable room for doubt. Churchland, Crick and Koch (to begin with) all seem agree that the LGN has rich upward connections to the cortex in all mammals, while making little or no reference to any other pathways.
(BTW, have you considered how implausible your explanation is from an evolutionary standpoint?)
This is an immensely ironic statement. See my closing.
And, as we all know, these cortical pathways are the ones that make us intelligent, perceptive - and, dare I say it - conscious.
True, false and false, respectively.
(Snipping the lecture on the LGN....)
In other words, these bandwidth-limited ascending pathways represent a pretty trifling quantity of information passed on to the visual cortex from the LGN.
Oh, yes, that's the only possible explanation....
Well, what can I say? Cortex roolz! It's what makes us human.
*sigh*
Seriously, it's obvious that you're fairly well read but you have to careful not to identify too closely with certain researchers' narrow preoccupation's.
As opposed to you, who thoughtfully provided one reference to back his argument, and, ironically enough, a researcher who is 'preoccupied' spinal and cerebellar neurons.
As for the rest about the cortex, I would strongly suggest you read: Panksepp's Affective Neuroscience; virtually anything by Crick, Koch; Newman and Baars re. the ERTAS; Damasio as referenced by Calvin; anything by Doug Watt; or the papers here or at the ASSC's online conference about emotion before lecturing about the function of subcortical systems. (Good starting hints: your assessment interaction of emotion and sensory information is 180 degrees from the truth, and consciousness is not a cortical function.)
Nope, he's right, and you left out everything below the cerebrum.
;-)
The retina has some significant processing power of it's own--in fact, it is often used as a benchmark for measuring the brain's overall processing capabilities (wrongly, IMO, but that's not relevant). Both edge and movement detection are performed in the rear-most layer of the retina as a pre-processing step before the information is moved up the optic nerve.
The optic nerve feeds into the LGN (the expanded form of which is difficult to spell), which performs a great deal of processing in it's own right--it was, after all, the primary visual system for millions of years--including further (much more refined) edge and movement detection, some object recognition, attention, etc.
The result of that is forwarded to the cortex for the final processing we all know and love, which extends the capabilities of the retina and LGN greatly. However, by that stage the input has virtually no resemblance to the output from the retina, having been thoroughly digested by the lower visual systems. (One further interesting tidbit: the descending pathways, from the cortex to the LGN, have 10x the capacity of the ascending pathways. Make of that what you will.)
(Incidentally, there are a number of us who are trying to combat cerebral chauvinism in neuroscience, and you aren't helping
I believe I remember it too, so you aren't imagine things. IIRC correctly, the retina's has around a millions cells, which would be equivelant to about half as many pixels (since a pixel incorporates the abilities of both a rod and a cone--er, or several rods and cones). The scanning (nuts, forgot the word) makes up for quite a bit, as does the processing capabilities of the tissue itself.
Which brings up the larger problem, IMO: the retina has some non-trivial image processing abilities, and AFAIK none of these implants go beyond simple light sensitive plates. To restore natural vision you'd need the replicate the entire million (IIRC) retinal cells, plus take some very tiny embedded processors in behind them (or to be biologically plausible, build the processors into the light detectors). These are relatively important functions, like edge and movement detection, that I don't believe it would be wise to leave out.
Er, my spellchecker's broken! Yeah, that's it....
I can think of at least three things wrong with this.
(1) I seen it stated that they aren't in the news.
(2) Intelligence test are 'questionable' measures of, um, anything (witness a recent Science News article explaining why inner city blacks score something like 20 points lower when the test is called and 'intelligence' test, but otherwise do quite normally). Moreso sinse they've only existed for ~90 years, and have only been really accurate for the last few decades, AFAIK. Difficult to say anything globally when 99.99...% of the population has never had an opportunity to take even a poor test.
(3) Given that most people, globally, are living essentially as they're ancestors (sp?) did several centuries ago (and occasionally, worse), the only possible explanation for this would be genetic, and I can assure you, that isn't it.
I agree, although I have a slightly different take on it. People probably aren't any dumber than before, but we should be smarter: we've had a few centuries of devotion to helping the common man, universal education, and all. The result? Nothing. Half the planet is still in the 12th Century, and other half would be if they didn't have to go to High School to get a job at McD's. Excellent progress.
Pepper gas != pepper spray. I apologize for assuming the correct terminology would be used, or that people would know what a 'spray' is.
Incidentally, the Fox story was considerably older than the CNN story; IIRC, from several hours before any statement had been made by the police, while it was happening. They can be forgiven for not wanting to sample the gas to see what it was.
Who would you rather believe; CNN, or Fox News?
I can't believe you seriously asked that; I'm relying on KIRO at the moment. However, given the choice between CNN and Fox--having watched the coverage from both--Fox is well ahead at this point.
-J, who would like to be home in Seattle, but is trapped in Oregon (the riot capital of the NW!).
*sigh*
I'll say this slowly: Fox News says the cops are using tear gas. They also have video of big clouds of what doesn't look much like pepper spray, coming out of grenades the cops are tossing. It just might be that they're using both, eh?
As for the paintball gun, you're right, it is.