Do you really imagine that the scientists working on this project don't know that? Of course they do. But the cell machinery in a small mycobacterium is extremely simple compared to that of a eukaryote like yeasts, amoebae or humans.
Even if they wanted to synthesize all the parts of the parent cell themselves, this would hardly be insurmountable - we have automated peptide synthesis machines now. And cell wall chemistry is well understood too.
But it's hardly likely to come to this. They will probably jsut take one specimen of the natural Mycoplasma they have been studying, remove its single plasmid and insert the one they've synthesized. In principle, this is a little like cloning of eukaryotes using a denucleated ovum.
Within just twenty hours of repeated division (assuming one cell division per hour) the original parent cell material will have been diluted by a factor of 2**20 (over a million) and well before that point the cells will be surviving solely on what enzymes and structural proteins they can synthesize for themselves with their artificial genome.
Consciousness is not what it thinks it is Thought exists only as an abstraction
I am myself a scientist by training. I didn't start out mistrustful. But I've lately come to realise that there's more motivation at work in many scientist's minds than the pure advancement of human knowledge, or the betterment of the human condition.
eg: Some of the scientists working on the Manhattan Project (esp. Edward Teller, but not Robert Oppenheimer)
eg: Nazi scientists working on "efficient" methods of human extermination and cruel medical experiments.
eg: The scientist who invented napalm.
eg: Randy Katz, inventor of Smart Dust microscopic bugging devices (mentioned in an article on Slashdot a few weeks ago). I don't mean to compare him with genocides, but he seems to care little about the potential for misuse of his devices.
Consciousness is not what it thinks it is Thought exists only as an abstraction
I'm sorry about your friend (we have "road rage" beatings and even murder here in the UK too).
I agreed with everything you said about morals, nihilism etc but I feel there has to be a better, more rational way than institutionalised belief in being who may not exist at all. Are we doomed never to advance in our belief systems beyond medieval superstition?
Religion only works because most people are credulous fools (witness the resurgence of mysticism and all the "New Age" throwaway cults around these days). It just wouldn't survive if people were better educated. IMO increasing standards of education are precisely the reason why religion is dying out in the West.
Rather, teach philosophy and sociology in our schools as part of the basic curriculum. And vote in governments on a violent-crime-bashing, non-culturally-relativist platform.
Consciousness is not what it thinks it is Thought exists only as an abstraction
...they rarely stop and say "Hey wait a minute. Yes it would be cool if I could do this...but SHOULD I? What impact would it have?".
No I'm sure almost all scientists would stop for a moment to ponder those very same things. But you omitted the second half of the monologue:
"Hey, wait, if I don't do it then someone else will only I won't get the credit. And it won't get misused because the government surely won't allow that, right? So what the hell - fame here I come."
Consciousness is not what it thinks it is Thought exists only as an abstraction
You're not thinking straight. In a tiny colony of a million bacteria who undergo fission about once every hour, a mutation affects only one of them. If the worst comes to the worst, it dies. The other 999,999 go on to become 1,999,998 within the next hour. If the food supply is limited, many individual bacteria may mutate themselves to death without affecting the climax population size or even substantially impacting the time taken to get there. So mutations even in vital genes are not really a problem.
And of course mutations in "junk" DNA are of neutral value to the organism.
Organisms which have a short life cycle are designed to cope very well with a high proportion of deleterious mutations, because the losers are quickly replaced. And some mutations which are deleterious under normal circumstances are advantageous in others, so today's weakly mutant is tomorrow's lucky survivor with all the food to himself.
Thus the net value to a bacterium of mutation in vital genes is probably positive.
Consciousness is not what it thinks it is Thought exists only as an abstraction
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.
I never contested their empirical results. They are at least rigorous enough as experimentalists. But do their opinions outweigh mine? Even if their opinions are not fully supported by their own results, and even if neither you nor I believe them, and even if *my* opinions are merely an expression of the establishment view? I think you overstate your case.
the cortex is not required for perception
It's been adequately established that cortex is required for conscious perception in humans (see below).
Animals lacking a cortex may be conscious. QED.
You're just being contentious, you can't possibly believe that because (i) QED means "that which is proven" while consciousness is not amenable to normal standards of proof even in humans; and (ii) to define consciousness broadly enough to encompass mental states in both humans and sea slugs would render the term practically useless.
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. ... 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.
Blindsight patients don't only fail to admit verbally to blindfield visual stimuli. They also fail to react physically in any manner which requires conscious assessment or determination. In the studies I've read about, the only direct reactions that occur appear to be fully subconscious, and indirect conscious reactions only occur when the subject receives substantial prompting.
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. 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. But can a visual processing system be conscious all by itself? The term 'conscious' can't be meaningfully applied to a small lump of brain tissue dedicated to a single passive function.
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.
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.
I don't remember who did the photoradiographs, I saw it many years ago in Colin Blakemore's The Mind Machine and I no longer have the book. I don't memorize lists of citations because I'm not a professional neurologist, I'm a dilettante who reads this stuff out of pure curiosity for my own amusement. However, I try to keep a broad view and I think I know what is what.
I certainly value my own objective (if undereducated) opinion this much: I remain sceptical about theories promoted by both narrow-minded specialists with a need to justify their next grant application, and I remain sceptical aout the work of eminent scientists practising their eminence outside of the field in which they won it.
The only current exception I make to this is Calvin, because his theory explains perfectly so much that is otherwise yet unexplained. Even if it turns out not to be completely correct, a cortex built according to his principles does look as if it would exhibit all the features of human memory, learning, cognition and yes even consciousness. The subcortical studies you are fond of are very important I agree. But I maintain that the cortex is capable of much neater stuff.
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?
Consciousness is not what it thinks it is Thought exists only as an abstraction
It's all going to go belly up some time in January or February.
Any dealer with a brain cell knows that certain sectors such as internet services and certain software stocks are massively overvalued. They also know that nobody is likely to bottle out just yet because, well, why should they? Thus they continue piling into hi-tech IPO's and anything with the trendy new open source label because they know from recent past experience that they'll make a quick killing.
At the same time they also know the market is expected to undergo occasional spontaneous corrections because it's chaotic and therefore unstable.
Brokers might be prepared to sail pretty close to the wire, but the key is to get out before everyone else does, so they're constantly sniffing for clues that the party is about to end. All it takes is for some news item to make a few dozen big brokers nervous at the same time, and they'll all start dumping stocks. And when one market starts this process, the others follow as the world turns.
Market falls are usually triggered by bad news of some global importance, but when stocks are overvalued it often appears that market reaction is still well out of proportion to the initial trigger. I'm thinking particularly of the 20% fall of the FTSE-100 (I think the Dow and the Hang Seng suffered about the same) during just a couple of days in 1998 because of a sudden loss of confidence. The real reason IMO was that a correction was simply overdue and somebody decided to get a head start on the others which got the ball rolling.
It's almost as if brokers in any given market share some sort of herd instinct. This is an inevitable aspect of the mediocrity of most dealers. Assuming that you don't know the market better than 90% of your fellows, the best way to keep your job is to be sure that you're doing what everyone else is doing even if it's against common sense. In other words, look out for trends and try to be one of the first to follow but don't get caught out there all by yourself. So they'll continue milking the cow for all it's worth until they begin to start feeling uncomfortable as the realisation slowly dawns that the cow they bought is little more than a mirage.
Surely many brokers must realise that time is almost upon them now. If so, many of them will be looking for a plausible excuse to switch strategy early next year. Of course they can't afford to just sell everything without good reason. But just about any bad news at all should provide a good enough excuse for the more cautious to ease themselves out of the game.
Fortunately for them, the media will be expecting a few Y2K glitches to hype up into front-page scare headlines. Now some minor Y2K cockups are inevitable even in those countries and corporations who dealt with the problem, and there are plenty of countries with significant economies who never really got it together. And our economies are all pretty tightly linked these days. So I believe those twitchy brokers will get their excuse.
When they do react, it won't go unnoticed. Trends are particularly easy to spot in electronic order driven markets, you just watch the online order book. So once people notice that the smart money is moving out, the trickle will rapidly become a flood.
I could be dead wrong about all of this but I feel it in my bones that a major market correction is on its way. I just hope the banks don't go down too like they did in 1929. If it's not just technology stocks but everything that's overvalued then we're in even bigger trouble. And that shortages stemming from interrupted supply lines (when producers and distribution companies find themselves paralysed by Y2K breakdowns) don't result in hyperinflation.
I'm certainly going to liquidate what stocks I have before the new year. The problem is, there's nowhere I can think of to put the proceeds that's immune to all of these risks:o/
Consciousness is not what it thinks it is Thought exists only as an abstraction
This is the third time I've tried to reply to this: the first time Netscape on Win98SE locked up, the second time Netscape on Linux locked up. Of course, in both cases it only decided to refuse access after a substantial amount of work.
So this time I'm going to be brief.
Crick and Koch and hundreds of other researchers (who I have read, in refereed journals like Trends in Cognitive Science) doing subcortical stuff make reasonable claims about subcortical perception and affect. But they don't claim that the cortex is idle, they are just focusing their effort elsewhere.
There are decades of cortical studies which have laid out how visual processing occurs in Primary Visual Cortex (PVC), handling low-level feature detection, motion detection and shape recognition; and also how there are pathways which send this information to other areas of cortex for recognition of higher-order stimuli and for association with inputs from other sensory modalities.
I again refer you to the photoradiographs of monkey PVC. They prove beyond doubt that retinal inputs arrive at the PVC largely unaltered by the subcortex. Even though the pathways do come through the LGN. It must be inferred that the LGN adds information to the retinal signal rather than replacing it with something completely different.
Gotta run now, more later.
Consciousness is not what it thinks it is Thought exists only as an abstraction
Why is everybody beating up on Sun about this? It's not as if they removed the credits to the Blackdown team, they're all still there in the documentation. So what should Sun have done? Called it "Sun Blackdown Java?" That would only dilute the Java brand and make it look like it wasn't the 100% pure Java thing.
I get the distinct feeling that Sun is coming under fire for this only because they are Sun and people don't like the SCSL. But what people need to realise is that Sun's support for open source efforts is a healthy thing for all of us. We now have an approved JDK and JVM. Yay! Much better that, than having Sun fight us tooth and nail, and publishing soppy MS-style "Linux Myths" pieces on their web site.
Sun should be applauded for going as far as they have. After all, they are a pretty damn big company who *still* depend upon their IP to stay in business, and it can't be an easy thing for a dinosaur to welcome the new sleek, fast, sharp-toothed mammals right into their midst.
If open source is as powerful as we all say it is, then Sun will realise in time that it is the way to go. We should give them our (guarded)support and go along with it. Yes, by all means, keep your powder dry.
With Intel, IBM, SGI, HP, Sun (and Dell and Compaq too) all contributing to the cause in one way or another, we have the greatest opportunity to win the marketing war against MS. We have *never* been in a stronger position.
Consciousness is not what it thinks it is Thought exists only as an abstraction
Napster can (should) be used to swap copies of music which is not under RIAA protection.
In seeking a blanket ban, the RIAA are effectively acting as a cartel, wielding monopoly control over the distribution of all music.
There's room for a counter-suit there if you ask me. And the amount of money required to settle that case would easily feed a dozen lawyers who could be hired on a "no-win-no-fee" basis.
Consciousness is not what it thinks it is Thought exists only as an abstraction
If my post was patronizing it was only appropriate as a response to the equally patronizing tone of your prior post. Look, sometimed it's hard to disagree without treading on people's toes. The only way to proceed is to try not to be too sensitive, and be prepared to admit defeat when beaten.
On with the show...
You are the champion of retinal processing, not me. As far as I'm concerned retinal processing is quite low-level. 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. Apart from the that retinal processing only consists of cleaning up the signal.
Parallel pathways exist all throughout the brain. I doubt that the optic nerve contains duplicate pathways for cortical and subcortical vision but this is hardly necessary anyway since the little higher level information from the retina (eg motion data) would only need to use a small number of specialised neurons hardly amounting to a complete duplication.
Hence, your question about how unprocessed information gets to the cortex when it's already been processed before it gets there is irrelevant. Raw monochrome information is transmitted alongside colour information and possibly motion information. They all pass by the thalamus, but the former two (at least) continue all the way to the cortex.
I've nothing more to say about retinal processing because photoradiographs of suitably dosed live visual cortex show irrefutably that the visual field is passed to it largely unchanged from the retina. Hence, as I said, there is no room for doubt. If there is any retinal processing, it's not important for cortical vision. It's just a camera which has some sophisticated error correction features to partially compensate for its design flaws.
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. Forgive me, but it seems as if you are trying to construct an argument about sensory perception involving a lot of different subsystems, from a partial understanding of a very limited and specific area of brain research.
Crick and the others make much of the LGN because that's what they're interested in. They're making a point about the way the thalamus modulates the conscious processing going on in the cortex. 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.
As far as evolution goes, I'll work up the theory for you: simple animals with no significant cortex evolved with relatively simple behaviour patterns (instincts) encoded entirely in subcortical pathways. Some animals were born with duplicated pathways which got organized differently and became cortex. This cortex enabled more detailed processing of sensory input and more creative generation of behaviour, supplementing and modulating the subcortical machinery, thus conferring survival advantage.
What's implausible about that?
You say that cortical pathways don't make us perceptive. Since roughly half of the cortex is concerned with processing sensory input (of which we are conscious) and which disappears when the relevant bit of cortex is taken away, I can't quite understand what you mean by that.
You also said cortical pathways don't make us conscious. Then you elaborated:
consciousness is not a cortical function
I'd like to see you prove that!
I didn't claim consciousness was merely a cortical function, anyway (see closing statement below).
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). I also said (with tongue firmly in cheek) that cortical pathways make us conscious.
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. I admit to the limitations of the behaviourist perspective but it's kind of hard to ignore the evidence all the same.
In the theoretical opposite case extrapolated from other brain damage case histories, if a human could be kept alive without most of his subcortex, he could probably still exhibit some apparently conscious behaviour but I expect he'd not have much to say about qualia which is what it's all supposed to be about. Actually this may become a real experiment sooner rather later. An Australian scientist recently announced an experiment where he was to temporarily deactivate parts of his brain using tuned oscillating electromagnetic fields.
So, in my opinion "consciousness" (the kind contemplated in the so-called "hard problem") is not a single unitary thing anyway. There's a whole spectrum of states of consciousness depending on how many parts of your brain are missing or otherwise in relative states of inactivity.
PS. I don't agree with some of Crick's work, and on the rest I don't have an opinion one way or the other because some of his conclusions go a little beyond what is warranted by the evidence. I try to keep an open mind. There's no doubt that almost all of the most exciting and revealing research right now is subcortical - there's so much structure there to be discovered. And so much of human nature is built on the same model as the rest of our animal cousins.
But the immense flexibility and power of the cortex in Calvin's model should not be discounted. It represents all of the capabilities we have that are uniquely human.
Consciousness is not what it thinks it is Thought exists only as an abstraction
I know you're just having a little joke...but there' something a little disturbing about the assumption inherent in the joke itself: is it necessary to be *queer* to be politically correct?
Warning: this is an off-topic rant appended to an already off-topic thread.
I am sick to death of the way our media, our political systems, our culture, and our education systems are being hijacked by a single minority. For this I'm branded a homophobe. Actually, I'm just normal. And I'd like the chance for my children to grow up normal without being "educated" about "alternative life choices".
OK, flame away. If anyone's still here that is...
Consciousness is not what it thinks it is Thought exists only as an abstraction
Yah, false alarm. The article states that international versions can already get 128 bit if issued with the right certificate when connecting to an appropriate server. Still, I'm not sure this is true. I've never heard of any institutions (banks etc) offering 128-bit secure connections outside of the US, and surely they'd be crowing it from the rooftops if it really was available.
For a minute there when I read the post I had visions of Bill Gates crapping his pants in fear anger and frustration. Would have been very nice if Netscape had *really* been given the right to export a strong crypto browser, and especially if MS had to wait for their turn until the DOJ thang was settled.
Consciousness is not what it thinks it is Thought exists only as an abstraction
Nightwatchmen in the UK are not like that, they're generally people who couldn't get a job doing anything else, or people who particularly need an evening job. They don't need any particular skills or experience (or intelligence for that matter). Similar to people who do the night shift work as a cashier in 24-hour "gas stations".
Consciousness is not what it thinks it is Thought exists only as an abstraction
This agrees with my own experience. The kids at college who got first class degrees weren't the brightest students, they were the ones who put in the most work.
Consciousness is not what it thinks it is Thought exists only as an abstraction
*Disclaimer*, this is not an insult to any employees of the all night chicken shack.
Oh come on, of course it is; you're saying that they are uneducated and/or stupid. Which some are, no doubt. And it's probably a stereotype shared by almost everyone with a more rewarding career.
But I've known postgraduate students (especially those from overseas) to take on part-time jobs as nightwatchmen, store assistants and short order cooks just to make ends meet, so it's not quite a foregone conclusion.
Consciousness is not what it thinks it is Thought exists only as an abstraction
I suggest that as a matter of convention, quarters should be expressed as YYQn or YYYYQn, eg. 99Q4, 1999Q4, 2000Q1, 00Q1. This has the advantages of being readable and also usable as a sort key. It should be mandated by ISO standard really. In fact, maybe it *is* in the ISO standard for Y2K compliant date formats. I seem to remember it does cover a lot of different formats.
Consciousness is not what it thinks it is Thought exists only as an abstraction
Victims of regular casual racism don't complain every single time it happens. Besides, if the demographics of slashdot readers were anything like that of the IT industry, or of the web surfing public as a whole (a matter of public record in both cases) then black people would be under-represented here.
I'm in the right, here. I tried to do the right thing, you're behaving like an insensitive, arrogant wanker. End of conversation. +++ATH
Consciousness is not what it thinks it is Thought exists only as an abstraction
I agree with you in princple. But it's not up to us, unfortunately.
The ABC article:
If they have failed, that would be a blow to NASA's strategy of building "faster, better, cheaper" spacecraft. Although NASA has had spectacular successes such as Mars Pathfinder and its rover Sojourner two years ago, some have begun to question whether the space agency has now pushed too fast and too cheap.
I'll say. But they won't get too many more chances, if indeed any. There are too many senators and congressmen who see NASA as the ideal whipping boy through whose persecution they can advance their own careers. They won't care if the amount of money wasted is "only" $200m. "Failure after failure" they'll howl. "How much more are we going to stand for?" they'll demand. And no-one will wish to be seen supporting a program that delivers successive failures.
It's not fair, but it looks like NASA's days are numbered. Even by the time I was finishing high school (around 1979) it was trendy to be against spending money on space exploration and for spending it on politically correct causes instead. How much truer is this now? Without widespread public support the space program is going nowhere. Remember the "smaller, faster, cheaper" philosophy wasn't an end in itself, it was the only possible response to a budget declining year-on-year.
I wish it weren't so. It's a crying shame that there was no proper followup to Apollo. We could've and should've been to Mars and back several times in the last 20 years. Maybe this is it. Maybe this is as far as we'll ever go. doesn't that prospect frighten you? It scares the hell out of me. No space travel=no point in going on, in my book. Might as well head back for the trees.
Consciousness is not what it thinks it is Thought exists only as an abstraction
Not only Mars and the belt: the larger satellites of Jupiter and Saturn may be viable.
The main problem is radiation - no magnetic field like earth to protect anyone on the surface. You'd have to spend most time indoors with a thick roof above your head if you're going to live there permanently.
That's the real bummer IMO, much worse than having a crap atmosphere. It'd be no fun going there if you can't spend much time outside even with a suit. I wonder what it would cost to spin up Mars' core and give it a magnetic field like Earth's.
Consciousness is not what it thinks it is Thought exists only as an abstraction
The retina has some significant processing power of it's own...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.
This preprocessed information only goes directly to the old subcortical vision systems. The primary visual cortex (which is where your "conscious" vision is) gets its data directly from the retina as a raw monochrome image plus low-resolution colour data, which is mixed in at a higher level, about where groups of edges and junctions get merged into identifiable surfaces.
...and you left out everything below the cerebrum...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.
I believe you are referring to the Lateral Geniculate Nucleus (this is off the top of my head so I can't guarantee the spelling). This has taken centre stage in subcortical processing studies lately as the old notion of the so-called "limbic system" as a complete and discrete subsystem has lost favour.
The subcortical visual processing pathways which evolved in our premammalian ancestors are an entirely separate issue from the conscious vision I was talking about in my previous post. The subcortical pathways are almost completely hardwired according to instructions in our genes, and they don't carry an awful lot of information: just very basic notification of possible threats (eg there's something moving towards you very quickly: predator!) and possible rewards (something moving away from you very quickly: prey!).
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.
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; the primary visual cortex is probably the most intensively studied region of the brain and the description I gave of cortical vision in my previous post is at least broadly correct. the data definitely comes direct from the retina.
The old subcortical sensory pathways evolved without having any substantial cortex to talk to. Their primary output is to subcortical switching centres like the thalamus, and from there on to affective systems such as motor areas in the cerebellum, autonomic systems in the brain stem regulating breathing, heart rate etc, and the adrenal response. These are relatively inflexible hardwired reflex systems - instinctive responses - originally developed for our simpler ancestors.
The way that the cortex has been overlaid on top of that is to provide a parallel (and almost completely independent) set of alternative pathways with their own (cortical) information processing. And, as we all know, these cortical pathways are the ones that make us intelligent, perceptive - and, dare I say it - conscious.
Now, there are secondary pathways swapping data between the subcortical and cortical systems, but these are very high level and, as you very conveniently pointed out:
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.
In other words, these bandwidth-limited ascending pathways represent a pretty trifling quantity of information passed on to the visual cortex from the LGN. It's a highly condensed "risk analysis" passed upwards for mixing in with the detailed sensory picture provided by the cortex to give it some emotional coloration. It adds an "Aaaaargh!!" factor to the beautiful scene of that huge muscular golden lioness bounding towards you.
The descending pathways are broader because they represent the cortex's afferent output, which is the whole point of having a cortex in the first place. These pathways feed into the old reflex pathways to modulate instinctive behaviour with intelligence and experience. Some of them are used when you "steel" yourself to do something which takes courage, or whenever you exert any kind of self-control against your base animal urges. The ones coming from deep inside the visual cortex carry learned information, (in this case, patterns representing recognised elements of a scene, such as a face you know) via the LGN to various midbrain structures where it acquires an emotional context (the face of a loved one or of a hated enemy). Whereupon appropriate signals are sent out to the hypothalamus, the brain stem etc. to prepare the body for the appropriate physical response.
(Incidentally, there are a number of us who are trying to combat cerebral chauvinism in neuroscience, and you aren't helping;-)
Well, what can I say? Cortex roolz! It's what makes us human.
Seriously, it's obvious that you're fairly well read but you have to careful not to identify too closely with certain researchers' narrow preoccupations.
Subcortical neurology explains most of the behaviour of lower animals. It also helps us to understand a lot of human behaviour; there's no doubt that it affects us deeply, we are still basically animals precisely because of it. However it cannot explain those parts of our experience and behaviour which make us different form other animals. Our conscious lives - our language, our appreciation for music, art, good food; our thirst for knowledge, our complex sexuality - these all belong in the information-rich cortex.
Please have a look at William H Calvin's web site, he has (I think all of) his books online there. His background is in spinal and cerebellar neurons but he has a brilliant theory of cortical processing which goes a long way to explaining how discrimination of complex stimuli, conscious and subconscious thought, memory, learning and language all work at a neuronal and cell-assembly level. I particularly recommend How Brains Think to start with.
Consciousness is not what it thinks it is Thought exists only as an abstraction
I dont think that a ccd camera with each pixel connected to a nerve in the optic cord would work because your retina actualy has done a bunch of computation before the image is passed on. Your eye actualy finds edges at different orientations and light areas surrounded by dark areas. It does more than that, but I dont have any examples to give. If you could do those computations and then feed the resulting signal to the brain you would have a much better chance of it learning to see again.
I'm not sure that's right. Feature detection (eg detection of edges, junctions etc) is done in the primary visual cortex. The cortex is composed of groups of about 100 "pyramidal" neurons wired together into narrow bundles, sometimes called minicolumns. Approximately 100 of these minicolumns are grouped together into a "macrocolumn" (in the visual cortex sometimes the term "ocular dominance column" is used).
Each macrocolumn is wired up to a specific spot on the retina, so that it might be regarded as processing a single pixel. In this way the entire visual field is mapped onto the surface of the back of the brain with relatively little distortion (feed radioactive glucose to a monkey, get him to look at a black-and-white geometric pattern while exposing the back of his head to photographic film, and you'll see the pattern he is looking at etched directly onto the surface of his brain!).
Now, within a given macrocolumn, each minicolumn is responsible for detection of a specific low-level feature at the co-ordinate "owned" by the macrocolumn to which it belongs. The features detected at this level are "edges" (sharp contrast gradients) in a complete range of different orientations, with a resolution of a couple of degrees.
Recognition of features such as vertical lines is accomplished by having the "vertical edge" minicolumns in adjacent macrocolumns connected to each other, and to specific multipolar neurons deeper in the cortex, which sum their inputs. So if the vertical edge detectors are stimulated in half a dozen macrocolumns all arranged (in terms of neural topology) in a straight line, these will all stimulate the higher-order neurons which code for a vertical line at those coordinates.
The processing that occurs in the retina owing to interconnection of rods and cones only involves smearing out the stimulus to near neighbours. I think this is part of the scanning mechanism involves in the eye's oscillation of approx. 10hz (I'm not referring to saccadic movement).
Consciousness is not what it thinks it is Thought exists only as an abstraction
Slashdot Mirror
Do you really imagine that the scientists working on this project don't know that? Of course they do. But the cell machinery in a small mycobacterium is extremely simple compared to that of a eukaryote like yeasts, amoebae or humans.
Even if they wanted to synthesize all the parts of the parent cell themselves, this would hardly be insurmountable - we have automated peptide synthesis machines now. And cell wall chemistry is well understood too.
But it's hardly likely to come to this. They will probably jsut take one specimen of the natural Mycoplasma they have been studying, remove its single plasmid and insert the one they've synthesized. In principle, this is a little like cloning of eukaryotes using a denucleated ovum.
Within just twenty hours of repeated division (assuming one cell division per hour) the original parent cell material will have been diluted by a factor of 2**20 (over a million) and well before that point the cells will be surviving solely on what enzymes and structural proteins they can synthesize for themselves with their artificial genome.
Consciousness is not what it thinks it is
Thought exists only as an abstraction
Your argument is spurious. If it were not, there would be no pathogenic bacteria.
Consciousness is not what it thinks it is
Thought exists only as an abstraction
I am myself a scientist by training. I didn't start out mistrustful. But I've lately come to realise that there's more motivation at work in many scientist's minds than the pure advancement of human knowledge, or the betterment of the human condition.
eg: Some of the scientists working on the Manhattan Project (esp. Edward Teller, but not Robert Oppenheimer)
eg: Nazi scientists working on "efficient" methods of human extermination and cruel medical experiments.
eg: The scientist who invented napalm.
eg: Randy Katz, inventor of Smart Dust microscopic bugging devices (mentioned in an article on Slashdot a few weeks ago). I don't mean to compare him with genocides, but he seems to care little about the potential for misuse of his devices.
Consciousness is not what it thinks it is
Thought exists only as an abstraction
I'm sorry about your friend (we have "road rage" beatings and even murder here in the UK too).
I agreed with everything you said about morals, nihilism etc but I feel there has to be a better, more rational way than institutionalised belief in being who may not exist at all. Are we doomed never to advance in our belief systems beyond medieval superstition?
Religion only works because most people are credulous fools (witness the resurgence of mysticism and all the "New Age" throwaway cults around these days). It just wouldn't survive if people were better educated. IMO increasing standards of education are precisely the reason why religion is dying out in the West.
Rather, teach philosophy and sociology in our schools as part of the basic curriculum. And vote in governments on a violent-crime-bashing, non-culturally-relativist platform.
Consciousness is not what it thinks it is
Thought exists only as an abstraction
...they rarely stop and say "Hey wait a minute. Yes it would be cool if I could do this...but SHOULD I? What impact would it have?".
No I'm sure almost all scientists would stop for a moment to ponder those very same things. But you omitted the second half of the monologue:
"Hey, wait, if I don't do it then someone else will only I won't get the credit. And it won't get misused because the government surely won't allow that, right? So what the hell - fame here I come."
Consciousness is not what it thinks it is
Thought exists only as an abstraction
You're not thinking straight. In a tiny colony of a million bacteria who undergo fission about once every hour, a mutation affects only one of them. If the worst comes to the worst, it dies. The other 999,999 go on to become 1,999,998 within the next hour. If the food supply is limited, many individual bacteria may mutate themselves to death without affecting the climax population size or even substantially impacting the time taken to get there. So mutations even in vital genes are not really a problem.
And of course mutations in "junk" DNA are of neutral value to the organism.
Organisms which have a short life cycle are designed to cope very well with a high proportion of deleterious mutations, because the losers are quickly replaced. And some mutations which are deleterious under normal circumstances are advantageous in others, so today's weakly mutant is tomorrow's lucky survivor with all the food to himself.
Thus the net value to a bacterium of mutation in vital genes is probably positive.
Consciousness is not what it thinks it is
Thought exists only as an abstraction
Continued.
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.
I never contested their empirical results. They are at least rigorous enough as experimentalists.
But do their opinions outweigh mine? Even if their opinions are not fully supported by their own results, and even if neither you nor I believe them, and even if *my* opinions are merely an expression of the establishment view? I think you overstate your case.
the cortex is not required for perception
It's been adequately established that cortex is required for conscious perception in humans (see below).
Animals lacking a cortex may be conscious. QED.
You're just being contentious, you can't possibly believe that because (i) QED means "that which is proven" while consciousness is not amenable to normal standards of proof even in humans; and (ii) to define consciousness broadly enough to encompass mental states in both humans and sea slugs would render the term practically useless.
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.
...
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.
Blindsight patients don't only fail to admit verbally to blindfield visual stimuli. They also fail to react physically in any manner which requires conscious assessment or determination. In the studies I've read about, the only direct reactions that occur appear to be fully subconscious, and indirect conscious reactions only occur when the subject receives substantial prompting.
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. 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. But can a visual processing system be conscious all by itself? The term 'conscious' can't be meaningfully applied to a small lump of brain tissue dedicated to a single passive function.
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.
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.
I don't remember who did the photoradiographs, I saw it many years ago in Colin Blakemore's The Mind Machine and I no longer have the book. I don't memorize lists of citations because I'm not a professional neurologist, I'm a dilettante who reads this stuff out of pure curiosity for my own amusement. However, I try to keep a broad view and I think I know what is what.
I certainly value my own objective (if undereducated) opinion this much: I remain sceptical about theories promoted by both narrow-minded specialists with a need to justify their next grant application, and I remain sceptical aout the work of eminent scientists practising their eminence outside of the field in which they won it.
The only current exception I make to this is Calvin, because his theory explains perfectly so much that is otherwise yet unexplained. Even if it turns out not to be completely correct, a cortex built according to his principles does look as if it would exhibit all the features of human memory, learning, cognition and yes even consciousness. The subcortical studies you are fond of are very important I agree. But I maintain that the cortex is capable of much neater stuff.
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?
Consciousness is not what it thinks it is
Thought exists only as an abstraction
It's all going to go belly up some time in January or February.
:o/
Any dealer with a brain cell knows that certain sectors such as internet services and certain software stocks are massively overvalued. They also know that nobody is likely to bottle out just yet because, well, why should they? Thus they continue piling into hi-tech IPO's and anything with the trendy new open source label because they know from recent past experience that they'll make a quick killing.
At the same time they also know the market is expected to undergo occasional spontaneous corrections because it's chaotic and therefore unstable.
Brokers might be prepared to sail pretty close to the wire, but the key is to get out before everyone else does, so they're constantly sniffing for clues that the party is about to end. All it takes is for some news item to make a few dozen big brokers nervous at the same time, and they'll all start dumping stocks. And when one market starts this process, the others follow as the world turns.
Market falls are usually triggered by bad news of some global importance, but when stocks are overvalued it often appears that market reaction is still well out of proportion to the initial trigger. I'm thinking particularly of the 20% fall of the FTSE-100 (I think the Dow and the Hang Seng suffered about the same) during just a couple of days in 1998 because of a sudden loss of confidence. The real reason IMO was that a correction was simply overdue and somebody decided to get a head start on the others which got the ball rolling.
It's almost as if brokers in any given market share some sort of herd instinct. This is an inevitable aspect of the mediocrity of most dealers. Assuming that you don't know the market better than 90% of your fellows, the best way to keep your job is to be sure that you're doing what everyone else is doing even if it's against common sense. In other words, look out for trends and try to be one of the first to follow but don't get caught out there all by yourself. So they'll continue milking the cow for all it's worth until they begin to start feeling uncomfortable as the realisation slowly dawns that the cow they bought is little more than a mirage.
Surely many brokers must realise that time is almost upon them now. If so, many of them will be looking for a plausible excuse to switch strategy early next year. Of course they can't afford to just sell everything without good reason. But just about any bad news at all should provide a good enough excuse for the more cautious to ease themselves out of the game.
Fortunately for them, the media will be expecting a few Y2K glitches to hype up into front-page scare headlines. Now some minor Y2K cockups are inevitable even in those countries and corporations who dealt with the problem, and there are plenty of countries with significant economies who never really got it together. And our economies are all pretty tightly linked these days. So I believe those twitchy brokers will get their excuse.
When they do react, it won't go unnoticed. Trends are particularly easy to spot in electronic order driven markets, you just watch the online order book. So once people notice that the smart money is moving out, the trickle will rapidly become a flood.
I could be dead wrong about all of this but I feel it in my bones that a major market correction is on its way. I just hope the banks don't go down too like they did in 1929. If it's not just technology stocks but everything that's overvalued then we're in even bigger trouble. And that shortages stemming from interrupted supply lines (when producers and distribution companies find themselves paralysed by Y2K breakdowns) don't result in hyperinflation.
I'm certainly going to liquidate what stocks I have before the new year. The problem is, there's nowhere I can think of to put the proceeds that's immune to all of these risks
Consciousness is not what it thinks it is
Thought exists only as an abstraction
This is the third time I've tried to reply to this: the first time Netscape on Win98SE locked up, the second time Netscape on Linux locked up. Of course, in both cases it only decided to refuse access after a substantial amount of work.
So this time I'm going to be brief.
Crick and Koch and hundreds of other researchers (who I have read, in refereed journals like Trends in Cognitive Science) doing subcortical stuff make reasonable claims about subcortical perception and affect. But they don't claim that the cortex is idle, they are just focusing their effort elsewhere.
There are decades of cortical studies which have laid out how visual processing occurs in Primary Visual Cortex (PVC), handling low-level feature detection, motion detection and shape recognition; and also how there are pathways which send this information to other areas of cortex for recognition of higher-order stimuli and for association with inputs from other sensory modalities.
I again refer you to the photoradiographs of monkey PVC. They prove beyond doubt that retinal inputs arrive at the PVC largely unaltered by the subcortex. Even though the pathways do come through the LGN. It must be inferred that the LGN adds information to the retinal signal rather than replacing it with something completely different.
Gotta run now, more later.
Consciousness is not what it thinks it is
Thought exists only as an abstraction
Why is everybody beating up on Sun about this? It's not as if they removed the credits to the Blackdown team, they're all still there in the documentation. So what should Sun have done? Called it "Sun Blackdown Java?" That would only dilute the Java brand and make it look like it wasn't the 100% pure Java thing.
I get the distinct feeling that Sun is coming under fire for this only because they are Sun and people don't like the SCSL. But what people need to realise is that Sun's support for open source efforts is a healthy thing for all of us. We now have an approved JDK and JVM. Yay! Much better that, than having Sun fight us tooth and nail, and publishing soppy MS-style "Linux Myths" pieces on their web site.
Sun should be applauded for going as far as they have. After all, they are a pretty damn big company who *still* depend upon their IP to stay in business, and it can't be an easy thing for a dinosaur to welcome the new sleek, fast, sharp-toothed mammals right into their midst.
If open source is as powerful as we all say it is, then Sun will realise in time that it is the way to go. We should give them our (guarded)support and go along with it. Yes, by all means, keep your powder dry.
With Intel, IBM, SGI, HP, Sun (and Dell and Compaq too) all contributing to the cause in one way or another, we have the greatest opportunity to win the marketing war against MS. We have *never* been in a stronger position.
Consciousness is not what it thinks it is
Thought exists only as an abstraction
Napster can (should) be used to swap copies of music which is not under RIAA protection.
In seeking a blanket ban, the RIAA are effectively acting as a cartel, wielding monopoly control over the distribution of all music.
There's room for a counter-suit there if you ask me. And the amount of money required to settle that case would easily feed a dozen lawyers who could be hired on a "no-win-no-fee" basis.
Consciousness is not what it thinks it is
Thought exists only as an abstraction
If my post was patronizing it was only appropriate as a response to the equally patronizing tone of your prior post. Look, sometimed it's hard to disagree without treading on people's toes. The only way to proceed is to try not to be too sensitive, and be prepared to admit defeat when beaten.
On with the show...
You are the champion of retinal processing, not me. As far as I'm concerned retinal processing is quite low-level. 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. Apart from the that retinal processing only consists of cleaning up the signal.
Parallel pathways exist all throughout the brain. I doubt that the optic nerve contains duplicate pathways for cortical and subcortical vision but this is hardly necessary anyway since the little higher level information from the retina (eg motion data) would only need to use a small number of specialised neurons hardly amounting to a complete duplication.
Hence, your question about how unprocessed information gets to the cortex when it's already been processed before it gets there is irrelevant. Raw monochrome information is transmitted alongside colour information and possibly motion information. They all pass by the thalamus, but the former two (at least) continue all the way to the cortex.
I've nothing more to say about retinal processing because photoradiographs of suitably dosed live visual cortex show irrefutably that the visual field is passed to it largely unchanged from the retina. Hence, as I said, there is no room for doubt. If there is any retinal processing, it's not important for cortical vision. It's just a camera which has some sophisticated error correction features to partially compensate for its design flaws.
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. Forgive me, but it seems as if you are trying to construct an argument about sensory perception involving a lot of different subsystems, from a partial understanding of a very limited and specific area of brain research.
Crick and the others make much of the LGN because that's what they're interested in. They're making a point about the way the thalamus modulates the conscious processing going on in the cortex. 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.
As far as evolution goes, I'll work up the theory for you: simple animals with no significant cortex evolved with relatively simple behaviour patterns (instincts) encoded entirely in subcortical pathways. Some animals were born with duplicated pathways which got organized differently and became cortex. This cortex enabled more detailed processing of sensory input and more creative generation of behaviour, supplementing and modulating the subcortical machinery, thus conferring survival advantage.
What's implausible about that?
You say that cortical pathways don't make us perceptive. Since roughly half of the cortex is concerned with processing sensory input (of which we are conscious) and which disappears when the relevant bit of cortex is taken away, I can't quite understand what you mean by that.
You also said cortical pathways don't make us conscious. Then you elaborated:
consciousness is not a cortical function
I'd like to see you prove that!
I didn't claim consciousness was merely a cortical function, anyway (see closing statement below).
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). I also said (with tongue firmly in cheek) that cortical pathways make us conscious.
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. I admit to the limitations of the behaviourist perspective but it's kind of hard to ignore the evidence all the same.
In the theoretical opposite case extrapolated from other brain damage case histories, if a human could be kept alive without most of his subcortex, he could probably still exhibit some apparently conscious behaviour but I expect he'd not have much to say about qualia which is what it's all supposed to be about. Actually this may become a real experiment sooner rather later. An Australian scientist recently announced an experiment where he was to temporarily deactivate parts of his brain using tuned oscillating electromagnetic fields.
So, in my opinion "consciousness" (the kind contemplated in the so-called "hard problem") is not a single unitary thing anyway. There's a whole spectrum of states of consciousness depending on how many parts of your brain are missing or otherwise in relative states of inactivity.
PS. I don't agree with some of Crick's work, and on the rest I don't have an opinion one way or the other because some of his conclusions go a little beyond what is warranted by the evidence. I try to keep an open mind. There's no doubt that almost all of the most exciting and revealing research right now is subcortical - there's so much structure there to be discovered. And so much of human nature is built on the same model as the rest of our animal cousins.
But the immense flexibility and power of the cortex in Calvin's model should not be discounted. It represents all of the capabilities we have that are uniquely human.
Consciousness is not what it thinks it is
Thought exists only as an abstraction
I know you're just having a little joke...but there' something a little disturbing about the assumption inherent in the joke itself: is it necessary to be *queer* to be politically correct?
Warning: this is an off-topic rant appended to an already off-topic thread.
I am sick to death of the way our media, our political systems, our culture, and our education systems are being hijacked by a single minority. For this I'm branded a homophobe. Actually, I'm just normal. And I'd like the chance for my children to grow up normal without being "educated" about "alternative life choices".
OK, flame away. If anyone's still here that is...
Consciousness is not what it thinks it is
Thought exists only as an abstraction
Yah, false alarm. The article states that international versions can already get 128 bit if issued with the right certificate when connecting to an appropriate server. Still, I'm not sure this is true. I've never heard of any institutions (banks etc) offering 128-bit secure connections outside of the US, and surely they'd be crowing it from the rooftops if it really was available.
For a minute there when I read the post I had visions of Bill Gates crapping his pants in fear anger and frustration. Would have been very nice if Netscape had *really* been given the right to export a strong crypto browser, and especially if MS had to wait for their turn until the DOJ thang was settled.
Consciousness is not what it thinks it is
Thought exists only as an abstraction
Nightwatchmen in the UK are not like that, they're generally people who couldn't get a job doing anything else, or people who particularly need an evening job. They don't need any particular skills or experience (or intelligence for that matter). Similar to people who do the night shift work as a cashier in 24-hour "gas stations".
Consciousness is not what it thinks it is
Thought exists only as an abstraction
This agrees with my own experience. The kids at college who got first class degrees weren't the brightest students, they were the ones who put in the most work.
Consciousness is not what it thinks it is
Thought exists only as an abstraction
*Disclaimer*, this is not an insult to any employees of the all night chicken shack.
Oh come on, of course it is; you're saying that they are uneducated and/or stupid. Which some are, no doubt. And it's probably a stereotype shared by almost everyone with a more rewarding career.
But I've known postgraduate students (especially those from overseas) to take on part-time jobs as nightwatchmen, store assistants and short order cooks just to make ends meet, so it's not quite a foregone conclusion.
Consciousness is not what it thinks it is
Thought exists only as an abstraction
I suggest that as a matter of convention, quarters should be expressed as YYQn or YYYYQn, eg. 99Q4, 1999Q4, 2000Q1, 00Q1. This has the advantages of being readable and also usable as a sort key. It should be mandated by ISO standard really. In fact, maybe it *is* in the ISO standard for Y2K compliant date formats. I seem to remember it does cover a lot of different formats.
Consciousness is not what it thinks it is
Thought exists only as an abstraction
Victims of regular casual racism don't complain every single time it happens. Besides, if the demographics of slashdot readers were anything like that of the IT industry, or of the web surfing public as a whole (a matter of public record in both cases) then black people would be under-represented here.
I'm in the right, here. I tried to do the right thing, you're behaving like an insensitive, arrogant wanker. End of conversation. +++ATH
Consciousness is not what it thinks it is
Thought exists only as an abstraction
Never thought I'd be grateful for the Chinese.
Could this spawn another space race?
Consciousness is not what it thinks it is
Thought exists only as an abstraction
PLEASE... racist, joke deleted.... Get over yourself. Since when does circumstantial humour == racism.
The joke is funny. I laughed when I first heard it many years ago. But it is offensive and demeaning to black people (as if you didn't know).
Consciousness is not what it thinks it is
Thought exists only as an abstraction
The ABC article:
I'll say. But they won't get too many more chances, if indeed any. There are too many senators and congressmen who see NASA as the ideal whipping boy through whose persecution they can advance their own careers. They won't care if the amount of money wasted is "only" $200m. "Failure after failure" they'll howl. "How much more are we going to stand for?" they'll demand. And no-one will wish to be seen supporting a program that delivers successive failures.
It's not fair, but it looks like NASA's days are numbered. Even by the time I was finishing high school (around 1979) it was trendy to be against spending money on space exploration and for spending it on politically correct causes instead. How much truer is this now?
Without widespread public support the space program is going nowhere. Remember the "smaller, faster, cheaper" philosophy wasn't an end in itself, it was the only possible response to a budget declining year-on-year.
I wish it weren't so. It's a crying shame that there was no proper followup to Apollo. We could've and should've been to Mars and back several times in the last 20 years. Maybe this is it. Maybe this is as far as we'll ever go. doesn't that prospect frighten you? It scares the hell out of me. No space travel=no point in going on, in my book. Might as well head back for the trees.
Consciousness is not what it thinks it is
Thought exists only as an abstraction
Not only Mars and the belt: the larger satellites of Jupiter and Saturn may be viable.
The main problem is radiation - no magnetic field like earth to protect anyone on the surface. You'd have to spend most time indoors with a thick roof above your head if you're going to live there permanently.
That's the real bummer IMO, much worse than having a crap atmosphere. It'd be no fun going there if you can't spend much time outside even with a suit. I wonder what it would cost to spin up Mars' core and give it a magnetic field like Earth's.
Consciousness is not what it thinks it is
Thought exists only as an abstraction
The retina has some significant processing power of it's own...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.
...and you left out everything below the cerebrum...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.
;-)
This preprocessed information only goes directly to the old subcortical vision systems. The primary visual cortex (which is where your "conscious" vision is) gets its data directly from the retina as a raw monochrome image plus low-resolution colour data, which is mixed in at a higher level, about where groups of edges and junctions get merged into identifiable surfaces.
I believe you are referring to the Lateral Geniculate Nucleus (this is off the top of my head so I can't guarantee the spelling). This has taken centre stage in subcortical processing studies lately as the old notion of the so-called "limbic system" as a complete and discrete subsystem has lost favour.
The subcortical visual processing pathways which evolved in our premammalian ancestors are an entirely separate issue from the conscious vision I was talking about in my previous post. The subcortical pathways are almost completely hardwired according to instructions in our genes, and they don't carry an awful lot of information: just very basic notification of possible threats (eg there's something moving towards you very quickly: predator!) and possible rewards (something moving away from you very quickly: prey!).
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.
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; the primary visual cortex is probably the most intensively studied region of the brain and the description I gave of cortical vision in my previous post is at least broadly correct. the data definitely comes direct from the retina.
The old subcortical sensory pathways evolved without having any substantial cortex to talk to. Their primary output is to subcortical switching centres like the thalamus, and from there on to affective systems such as motor areas in the cerebellum, autonomic systems in the brain stem regulating breathing, heart rate etc, and the adrenal response. These are relatively inflexible hardwired reflex systems - instinctive responses - originally developed for our simpler ancestors.
The way that the cortex has been overlaid on top of that is to provide a parallel (and almost completely independent) set of alternative pathways with their own (cortical) information processing. And, as we all know, these cortical pathways are the ones that make us intelligent, perceptive - and, dare I say it - conscious.
Now, there are secondary pathways swapping data between the subcortical and cortical systems, but these are very high level and, as you very conveniently pointed out:
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.
In other words, these bandwidth-limited ascending pathways represent a pretty trifling quantity of information passed on to the visual cortex from the LGN. It's a highly condensed "risk analysis" passed upwards for mixing in with the detailed sensory picture provided by the cortex to give it some emotional coloration. It adds an "Aaaaargh!!" factor to the beautiful scene of that huge muscular golden lioness bounding towards you.
The descending pathways are broader because they represent the cortex's afferent output, which is the whole point of having a cortex in the first place. These pathways feed into the old reflex pathways to modulate instinctive behaviour with intelligence and experience. Some of them are used when you "steel" yourself to do something which takes courage, or whenever you exert any kind of self-control against your base animal urges. The ones coming from deep inside the visual cortex carry learned information, (in this case, patterns representing recognised elements of a scene, such as a face you know) via the LGN to various midbrain structures where it acquires an emotional context (the face of a loved one or of a hated enemy). Whereupon appropriate signals are sent out to the hypothalamus, the brain stem etc. to prepare the body for the appropriate physical response.
(Incidentally, there are a number of us who are trying to combat cerebral chauvinism in neuroscience, and you aren't helping
Well, what can I say? Cortex roolz! It's what makes us human.
Seriously, it's obvious that you're fairly well read but you have to careful not to identify too closely with certain researchers' narrow preoccupations.
Subcortical neurology explains most of the behaviour of lower animals. It also helps us to understand a lot of human behaviour; there's no doubt that it affects us deeply, we are still basically animals precisely because of it. However it cannot explain those parts of our experience and behaviour which make us different form other animals. Our conscious lives - our language, our appreciation for music, art, good food; our thirst for knowledge, our complex sexuality - these all belong in the information-rich cortex.
Please have a look at William H Calvin's web site, he has (I think all of) his books online there. His background is in spinal and cerebellar neurons but he has a brilliant theory of cortical processing which goes a long way to explaining how discrimination of complex stimuli, conscious and subconscious thought, memory, learning and language all work at a neuronal and cell-assembly level. I particularly recommend How Brains Think to start with.
Consciousness is not what it thinks it is
Thought exists only as an abstraction
I dont think that a ccd camera with each pixel connected to a nerve in the optic cord would work because your retina actualy has done a bunch of computation before the image is passed on. Your eye actualy finds edges at different orientations and light areas surrounded by dark areas. It does more than that, but I dont have any examples to give. If you could do those computations and then feed the resulting signal to the brain you would have a much better chance of it learning to see again.
I'm not sure that's right. Feature detection (eg detection of edges, junctions etc) is done in the primary visual cortex. The cortex is composed of groups of about 100 "pyramidal" neurons wired together into narrow bundles, sometimes called minicolumns. Approximately 100 of these minicolumns are grouped together into a "macrocolumn" (in the visual cortex sometimes the term "ocular dominance column" is used).
Each macrocolumn is wired up to a specific spot on the retina, so that it might be regarded as processing a single pixel. In this way the entire visual field is mapped onto the surface of the back of the brain with relatively little distortion (feed radioactive glucose to a monkey, get him to look at a black-and-white geometric pattern while exposing the back of his head to photographic film, and you'll see the pattern he is looking at etched directly onto the surface of his brain!).
Now, within a given macrocolumn, each minicolumn is responsible for detection of a specific low-level feature at the co-ordinate "owned" by the macrocolumn to which it belongs. The features detected at this level are "edges" (sharp contrast gradients) in a complete range of different orientations, with a resolution of a couple of degrees.
Recognition of features such as vertical lines is accomplished by having the "vertical edge" minicolumns in adjacent macrocolumns connected to each other, and to specific multipolar neurons deeper in the cortex, which sum their inputs. So if the vertical edge detectors are stimulated in half a dozen macrocolumns all arranged (in terms of neural topology) in a straight line, these will all stimulate the higher-order neurons which code for a vertical line at those coordinates.
The processing that occurs in the retina owing to interconnection of rods and cones only involves smearing out the stimulus to near neighbours. I think this is part of the scanning mechanism involves in the eye's oscillation of approx. 10hz (I'm not referring to saccadic movement).
Consciousness is not what it thinks it is
Thought exists only as an abstraction