The Phantom Compass Syndrome

April 5, 2007 2:27 AM

Hacking the Senses: The brain is far more plastic than we commonly realize. Presenting new 'senses' via the old inputs works extremely well, to the point that long-term volunteers are a little lost without their new abilities to feel magnetic north or absolute orientation. Tasting direction; feeling pictures. Fascinating stuff. In a loosely related article, genetically modified mice are able to see the full color range visible to humans, even though the last natural mouse able to see this way died out a hundred million years ago. Add the new sensors, and the brain reconfigures. [via]
posted by Malor (68 comments total)

I think this has always been known for quite a long time by the neurologists.

I also think that quite alot of people are in some sense also aware of this. After becoming accustomed to using a device, e.g. a keyboard, a bike, a car or even an airplane, the way a person uses it is to follow through on an action or desire without thinking about the specific usage-details the device itself requires, e.g. type a word, turn left, turn right, fly up or down. In a way our senses somehow extent to that device, think of when you're parallel parking your car or driving through a very narrow alley. Unfortunately we don't have direct feedback concerning unattached devices.

But a much more basic example of this extension of yourself to a device you constantly use, is your complete body and your senses themselves. We've of course forgotten the learning period, but I think there is little principle difference. The two main differences are the huge scale of versatility our bodies give us and the huge amount of feed-back data that we get from our bodies and senses.

Another nice example of "rewiring" is the nice experiment with the glasses made of prisms, that turn the wearers visual world upside-down. This is an experiment that was done 1896 by George Stratton. His motivation was that since the image is actually feed to the brain upside-down, why not rightside-up it before it's processed. Of course, this begs the question: why should processing visual data have orientation at all? The answer is that orientation is irrelevant. After a few days of "rewiring" the images are processed in the usual manner...

A more interesting idea would be to totally (but only seemingly) scramble the visual image without destroying information and see how long a wearer needs to become accostomed to that...
(e.g. in the link above wearer only inverted the visual image)
posted by umop-apisdn at 3:02 AM on April 5, 2007 [1 favorite]

The commentary's conclusions about the mice trichromaticity bothers me a little. Are they sure that the neurology for trichromaticity isn't vestigial and that's why adding the gene for the third pigment worked and not because (presumably) the mammalian brain will just adapt and utilize the new information?

I'd been thinking about this for a long time in the context of the very few human tetrachromats that are thought to exist. My lay understanding of human vision with regard to the brain led me to expect that even were someone to have the tetrachromat mutation and thus have the fourth pigmented cone, they'd still not see new colors because there wouldn't be the neurology to support it. And yet, some researchers expect they will and supposedly the one possible tetrachromat identified, "Mrs. M", sees more colors.

And so we have this experiment, which points in that same direction.

Looking through the above Google search results for tetrachromat, I see one web page that asserts that humans and many other animals are "blocked tetrachromats". I don't know whether that page is crankish or not, but the idea is plausible, it seems to me. It depends upon the evolution of color vision in this lineage. Maybe the earlier adaptation was for tetrachromaticity but later on it was selected against in favor of less color discrimination. Keep in mind that color vision is synthetic, it doesn't reflect reality, the qualitative differences between colors we experience with color vision are entirely the product of our brains. This can be good and bad.

It's a really good "hack" because it makes the relevant information so damn obvious: red and blue are different. A true tetrachromat will experience the same qualitative distinction within what we experience as shades of the same color. So you can see how this qualitative distinction can be both selected for and against. It's selected for when making that synthetic qualitative distinction reflects a real-world distinction that is important. It's selected against when that synthetic qualitative distinction doesn't reflect something important in the real-world and distinguishes two things that are better experienced as being similar. In this context, I can imagine tetrachromats evolving such that they become trichromats or bichromats. And if that's the case, then there may remain sufficient vestigial brain function for it to be restored with a mutation.

Alternatively, and agreeing with the conclusion in the linked article, the way the mammalian brain processes color may be organized in such a way and plastic enough to just work with the new information provided by the mutation. I know and understand that the brain is very, very plastic. But we're talking pretty low-level stuff here where we already know things about the neurology and we've identified specific structures that function in specific ways. Plasticity at this level seems surprising to me. At higher levels, I don't doubt, vis a vis the Wired article, that people integrate new senses into the paradigms of their existing sensorium. We already know this.

Incidentally, I'm certain that wiring in new I/O to a baby's brain, even in very ignorant and arbitrary ways, would result in a high level of integration and utility. It's too bad we won't do this.
posted by Ethereal Bligh at 3:04 AM on April 5, 2007

I think this has always been known for quite a long time by the neurologists.
posted by umop-apisdn at 3:04 AM on April 5, 2007

I'd pay a bundle for a watch band that was warmer in response to North.
posted by ewkpates at 3:15 AM on April 5, 2007

EB: Keep in mind that color vision is synthetic, it doesn't reflect reality

I agree with you, but it's controversial within the framework of physicalism.
posted by Gyan at 3:16 AM on April 5, 2007

Your Moralising Quotient of 0.38 compares to an average Moralising Quotient of 0.22. This means that as far as the events depicted in the scenarios featured in this activity are concerned you are less permissive than average.

Now wait a minute. Knocking the kid off the swing, the chicken fucking, the pet eating was all OK in my book, but I answer negative to incest and I am "less permissive" than average.

You average people are sick.
posted by three blind mice at 3:18 AM on April 5, 2007

Sorry, I've obviously put these comments in the wrong place.
posted by three blind mice at 3:20 AM on April 5, 2007

Wrong thread! Blind mice still blind.
posted by Gyan at 3:20 AM on April 5, 2007

"His motivation was that since the image is actually feed to the brain upside-down, why not rightside-up it before it's processed."

Okay, this bugs me. I can imagine someone that long ago thinking this, but it's nonsense. There is no "orientation" in that sense. The idea is the product of a strangely naive idea of vision. It means almost nothing to say that the image on the back of the eye is "upside down". The only orientation that exists is the mapping between the input and proprioception, our sense of our body in our environment. Think about it this way: if your video card and monitor worked in such a way (they don't, but for the sake of argument) that there were a bunch of tiny optical cables representing each of the pixels on the screen bundled together, would you say that the orientation where the cable plugs into the video card was "upside down" or otherwise? Yes, you could say that, but it isn't important. The cable could be oriented any way, even scrambled with no orientation, but as long as the connections are the right connections (meaning that the orientation is known), then it will work. The image on the back of the eye could be oriented relative to the outside of the body in any way and it would work just so long as the brain knows how that corresponds to the outside environment.

What Stratton's experiment showed, however, is that the information representing orientation is independent of the information of vision. That is to say, it's not "hardwired". It's not necessarily the case that orientation is actually represented as a discrete piece of information in the brain that it just needs to alter if the visual field changes (though that's possible). The other possibility is that processing connections between vision and proprioception and motor control is mediated by other things and orientation is implicit in that mediation. If the visual field orientation changes, it's not too difficult for the mediating layer to adjust.
posted by Ethereal Bligh at 3:21 AM on April 5, 2007 [1 favorite]

"I agree with you, but it's controversial within the framework of physicalism."

Gyan, I'd sure like to read that article. On first thought, it sounds like nonsense to me. On second thought, I can imagine that their argument might be that in our evolutionary environment the colors we experience map very well onto distinctions within our environment. Which is what you'd expect from an informed synthetic view (a synthetic view that results from the biology of color vision and evolutionary biology and not merely from physics). In this way, I guess, you could argue that these colors are "real".

But ultimately they are not. I don't see how you can avoid the simple fact that color vision tells us there are qualitative distinctions that cannot be claimed to be qualitative in physical reality. You also have the problem that color vision is faulty and lies to us, as is demonstrated by color display devices.
posted by Ethereal Bligh at 3:30 AM on April 5, 2007

"The brain is far more plastic than we commonly realize."

Speak for yourself!
posted by Eideteker at 3:45 AM on April 5, 2007

(and I say that as a psychologist, not a snarkeologist)
posted by Eideteker at 3:45 AM on April 5, 2007

So can we up vision for humans an order of magnitude (or ten) as well? I'll sign up to have the vision of an eagle.
posted by zardoz at 3:53 AM on April 5, 2007

My deaf aunt was thinking for a while about getting a cochlear implant (but she's 63 and decided that she'd probably have a hard time with it). While looking over all the informational booklets, web sites, and such, I was struck by the fact that they're not allowing people to hear outside of normal human ranges. That could be inconvenient in many situations, but it could be useful in others. I want to hear ultrasound. I want an ultrasound emitter with the cochlear implant and have the processor using interferometry when it passes the echoed ultrasound back to my brain ("seeing" like bats).

So many things are possible.

Zardoz, you already can get laser surgery to get your vision notably better than normal.
posted by Ethereal Bligh at 4:05 AM on April 5, 2007

umop-apisdn writes:

"...nice experiment with the glasses made of prisms, that turn the wearers visual world upside-down..."

Eponysterical!
posted by notsnot at 4:06 AM on April 5, 2007 [1 favorite]

I want to hear ultrasound.

Do you? I wonder what ultrasonic noise pollution is like.
posted by DU at 4:38 AM on April 5, 2007

Ethereal Bligh writes "their argument might be that in our evolutionary environment the colors we experience map very well onto distinctions within our environment."

Given the large number of animals that use bright colors as warning signals, I'd say that's a strong argument. Poison arrow frogs wouldn't be flashy unless it helped them avoid predation, for example.

As for the mice - well, we mammals went through a nocturnal phase a while back, when we were still dodging dinosaurs. Some of us went diurnal again later on. Those that did mostly benefited from color vision again, while those that didn't (the mice) didn't need the extra gene (extra in the sense that blue-green vision from rods is sufficient at night, even though trichromaticity is ancestral - we reverted, mice did not).

However, the brain development patterns did not also change. Just like the right signals can make a hen grow a tooth, or the fact that we have vestigial photoreceptors in our pineal gland (an organ that never sees light in mammals, barring major head trauma) - Having these things doesn't hurt us, so there is not necessarily any evolutionary pressure to remove them. The mice have a gene added - note that knock-in means added as an embryo, so they developed with this gene present, not that it was added to adult mice - the development patterns in the visual cortex have thus been shown to retain the ability to use this input in a logical way. What would be really, really interesting is to see if adding a fourth gene would result in tetrachromatic vision - now that would be really neat, because it would suggest that there is no hard-wired pattern to the organization of visual input per se, but rather a flexible generic program that determines how to organize incoming signals.

The brain is pretty damn cool.
posted by caution live frogs at 4:45 AM on April 5, 2007

This makes tremendous sense to me, because I can play the violin really well. And you may say ha! That's just a normal application of the sensory apparatus you already have!

And I'd reply that I have learned a special, really special relationship between vibrations that come up through my chin and the sense of friction in my right elbow and the fact that the open e string tastes like tin. And you haven't, which is why I'm a better fiddler than you are.

I have no doubt that new information grafted onto old sensory equipment can be integrated - these new "senses" are using the old circuitry. It's a hack. Of course it works.

It's neat, but it's not surprising.

As for the mice and their colour vision - all I can say is that the science of colour perception is an unholy alliance of psychology, physicics and biology, where questions like "it depends what 'red' is " are meaningful. When it's sorted in humans, then we can worry about mice.
posted by i_am_joe's_spleen at 4:48 AM on April 5, 2007 [1 favorite]

PS: there is some interesting research going on into control of electronic devices through mental effort. I would love to see that hooked up to the sensory research. Can you feel it when you mentally make a mouse click? My intution is that you can. And if you can, then please keep my brain in a jar. Fuck your weak organic superstructure - once I've got my singing dancing exoskeleton with boosters I'm flying to Mars. If I have my iPod loaded, to Alpha Centauri,
posted by i_am_joe's_spleen at 4:52 AM on April 5, 2007

PPS: given what the linked article says - where's my weird arse telepathy? Because if even the remotest tinglings were being picked up by the odd human brain, provided it were adaptive, we ought to see lots of it. And we don't.
posted by i_am_joe's_spleen at 4:55 AM on April 5, 2007

Are they sure that the neurology for trichromaticity isn't vestigial and that's why adding the gene for the third pigment worked and not because (presumably) the mammalian brain will just adapt and utilize the new information?

I can't find the reference right now, but there was a news article about the mouse paper the FPP refers to (it was either Nature or Science) and they referred to a study where near-UV-sensing apparatus was incorporated into a turtle retina (as a xenograft I think, not genetically) and the turtle appeared to acquire the ability to identify this color. So there's a suggestion this isn't just hooking into an unused portion of the developed brain.
posted by rxrfrx at 4:56 AM on April 5, 2007

I'd heard of this kind of thing before, but I didn't realize the brain could take input of totally new kinds of information (like compass headings) and integrate it in. Making one of those directional belts shouldn't be too hard with some pager motors and whatnot. Actually, the hardest part would probably be telling which way is north (magnetic compasses wouldn't be much use in an office building).
posted by DU at 4:57 AM on April 5, 2007

Reminds me of this, which I think is freaking cool. I think the killer augmentation has to be infrared vision though. I heard they've been making advances in retinal stimulation, so maybe it's not so far off - I reckon I could put up with looking like Batou in return for that.
posted by Drexen at 5:02 AM on April 5, 2007

This story (How Dilbert creator Scott Adams learned to re-map his brain to speak again) was the first thing I thought of. Brain re-mapping is clearly the way to go!
posted by TwoWordReview at 5:31 AM on April 5, 2007

There are some people with four optical pigment types, and they see four color channels just fine.
posted by delmoi at 5:40 AM on April 5, 2007

What's this about fucking chickens?

I kid. Fascinating topic, even if half of the conversation is over my head.
posted by LordSludge at 6:44 AM on April 5, 2007

"There are some people with four optical pigment types, and they see four color channels just fine."

Yes, that's been discussed. Except, no, I'm pretty sure that there's only one known tetrachromat. It's thought there must be a few others out there, but it's a very rare mutation. And the details of her color vision are not clear from what I've seen. It seems like the stuff with her was old and there's not been much since.

The part that's unclear to me is whether she's a true tetrachromat or whether she integrates the response from the fourth pigment into her trichromat sensorium (like the people in the Wired article). In the latter case, she'd still have some sort of heightened color vision, seeing distinctions that trichromats wouldn't see. But she wouldn't see those distinctions as qualitative additions to her rainbow. Experimentally distinguishing the two cases from each other might be quite difficult. I'm not sure.

Anyway, as discussed previously, true trichromaticity in the rat's case and true tetrachromaticity in Mrs. M's case are both very provocative. We know the brain is plastic at both the very lowest and very highest levels. But a lot of brain functions occur at the level of something like organs, areas that specialize in function. I'd expect the part of vision devoted to color to be highly specialized. It's astonishing that an additional color channel at input would be processed as an additional color channel through portions of the brain that have nothing to do with that mutation. Either the brain is plastic at this moderately-low level of specialized function, or the neurology for that functionality was already there. Frankly, I'm highly inclined to take the latter view. But what do I know? I'm no neurologist.
posted by Ethereal Bligh at 7:03 AM on April 5, 2007

"His motivation was that since the image is actually feed to the brain upside-down, why not rightside-up it before it's processed."

See, if I'd run that experiment, I'd have used an inverting lens on one eye only. Take that, brain!

They don't let me near live subjects anymore.
posted by Ritchie at 7:21 AM on April 5, 2007 [1 favorite]

I was having lunch at my house with friends, including a(unknown to me at the time) world famous typographer, and he was discussing how he had to understand how people viewed things to understand how to make things "better" to view.

He was rambling along at about 12 revelations per minute to me, and I was sitting there with a stupid grin on my face, and he mentioned how the brain isn't that worried about orientation when accepting input.

I requested further input on that statement, and he said "If you are watching a movie, sitting on your couch, and you lay down while continuing to watch, does that reduce your ability to watch the movie at all?".

I laughed at all the things I had never thought about, and a bunch of the people we were having lunch with immediately went to conduct experiments with my couch and television.

Experiment's conclusion? Brains are pretty neat, and most of us don't even think about it most of the time.
posted by dglynn at 7:22 AM on April 5, 2007

So we know the brain is plastic. How long before we start stuffing new chips in our head.
- A clock. I would like to have a perfect time sense. Some people have this naturally I have heard. Why wear a watch.
- A calculator. Again should be simple for the brain to figure out.
- Memory with a simple controller of some sort. I need this. You know, so I stop forgetting all my metafilter references.

But I think people would have issues with having their head opened up every time they want the next model. A clean way to do something like this might be to run lines from the electrodes in your brain under the skin to your wrist. Your wrist computer/phys link couples electromagnetically with the lines so you don't have any of those unsightly Matrix sockets.

Instead of wearing a watch you can wear you phy link sense computer of choice for the day.

Can we sense something like the internet through a none visual medium? How long before we intuitively sense how our friends are feeling over the net even though they are physically distant? What forms will communications take when we can project images or other senses to friends? Will it feel like putting on ear muffs when we take off our phys links or like blindness? Will we feel slow, stupid, numb without.

How long will it take for your brain to handle a new device. That internet module? That foreign language reference? That car control module? That factory status module? That stock market watcher? That XBOX 7 controller? What will it take to get high bandwidth input into the brain, like vision?

The man machine merger is nothing new to sci-fi but it still has so many open questions.
posted by restlessturtle at 7:23 AM on April 5, 2007

Say what you will, I still can't get this rubber arm I stapled onto my back to pick up things, and it's been there for nearly a year.
posted by Astro Zombie at 7:24 AM on April 5, 2007

notsnot writes
umop-apisdn writes:
"...nice experiment with the glasses made of prisms, that turn the wearers visual world upside-down..."
Eponysterical!

(; ¡leℑi⌋a|sλuod∃
(as seen from another POV *g*)

/hope all characters render correctly
\μob6 9ll cμ9⌊9c|6⌊s ⌊6uq6⌊ co⌊⌊6c|lλ
posted by umop-apisdn at 7:36 AM on April 5, 2007

The fact that the brain is digitally reproducible will be the culturally shifting discovery of the early 21st Century. Reproducible like an analog cello can be recorded on cd.
posted by Sparx at 7:52 AM on April 5, 2007

im in ur brain, h4ckin ur noorons

Things are going to get really interesting once brain hacking hits the mainstream; I hope we get there during my lifetime. It's been neat observing the development of PCs and the internet, but this... this could get crazy!

On the other hand, how long til the first person is r00ted?
posted by LordSludge at 8:02 AM on April 5, 2007

Sudo

Give me your password
posted by Sparx at 8:06 AM on April 5, 2007

the brain is digitally reproducible ... like an analog cello can be recorded on cd

That'll make for some interesting mash-ups, Mengele-style.
posted by CynicalKnight at 8:06 AM on April 5, 2007

One of my long standing fears is that some sort of direct brain-computer interface will be invented, and my brain will be too old to learn how to use it, and I will be made obsolete by legions of 20-somethings with wires hanging out of their necks.
posted by signal at 8:07 AM on April 5, 2007

interesting mash-ups, Mengele-style.

I would pay cash dollars for for Michael Jackson vs George Clooney
posted by Sparx at 8:15 AM on April 5, 2007

I'm surprised these two O'Reilly books haven't been mentioned yet:
• Mind Hacks Tips & Tricks for Using Your Brain
• Mind Performance Hacks Tips & Tools for Overclocking Your Brain
posted by umop-apisdn at 8:17 AM on April 5, 2007

I would like to have a perfect time sense. Some people have this naturally I have heard.

I can sorta do this, although most proficiently upon waking. I've impressed a sleeping companion or two over the years by being able to almost unerringly predict the time (within 5 min or so) upon waking, regardless of time of day or season. I'm good with time overall, but I only seem to pull that trick off after sleeping. Go figure.

I read a book some years back (cant recall the title or author - a sort of general science book about the future of technology and the human brain) wherein the author had a pretty neat concept that neurology and neuroscience was moving towards a kind of Grand Unification Theory of the brain. Wherein as we learn more about how the brain processes sensory information, we come to a point where we can explain "extrasensory" phenomena because all the senses are working together cognitively rather than being separated out.

I'm no neurologist so I have no idea if this is complete nonsense, but I liked the idea of it all.
posted by elendil71 at 8:34 AM on April 5, 2007

Mice with new genetically added abilities, huh. They should be checking those cages every night for rodents spontaneously shouting "NARF."

Like a canary dying in a coal mine, find one and you can be sure there's trouble nearby.
posted by JHarris at 8:37 AM on April 5, 2007

elendil : I've impressed a sleeping companion or two over the years by being able to almost unerringly predict the time (within 5 min or so) upon waking, regardless of time of day or season. I'm good with time overall, but I only seem to pull that trick off after sleeping. Go figure.

Not quite the same thing, but I've been saved from missing quite a few important meetings, exams, classes etc by my brain's near-unfailing ability to wake me up just in time to get to them, when I've forgotten to set my alarms - even if the necessary waking time is different from my normal waking time. It only works if I've thought about when I'll have to get up, the evening before. It's quite uncanny.

Hmmm. Maybe the next stage in human evolution is the in-ear alarm-clock implant. Won't wake your spouse! But if it malfunctions, you'll go insane!
posted by Drexen at 9:06 AM on April 5, 2007 [1 favorite]

"I'm good with time overall, but I only seem to pull that trick off after sleeping. Go figure."

I have really good time sense. I don't need to set an alarm because I will always wake up within a few minutes of when I set the alarm anyway. I used to have a very, very good sense of elapsed time and could guess the time within a matter of a few minutes for a period of a few hours after I was aware of the exact time. For a few years in the mid-90s I could blow people's minds doing this. I can't do this as well any more; I'm not sure why.

However, I still have extremely good sense of time, to the second, for periods of up to ten minutes or so. I'm not sure if that's inherent; I've always assumed I acquired this during the time I was an overnight disc-jockey. Just doing the job made me very aware of the timing of singles (and length of intros available for talkover). But I also tended to prowl the station and get into places where I couldn't hear what I was broadcasting and had to rely upon my time sense to tell me I needed to get back to the studio. I know extremely well exactly how long three and a half minutes is. Anyway, I'm usually walking up to the microwave when it beeps at me when I've heated something.

None of these are things I recall being skills I had as a child or when I was a teen. So I may have aquired them. Time sense is a pretty strange brain ability, if you think about it. I wonder how it works. It's probably an amalgam of an awareness of several different things.
posted by Ethereal Bligh at 9:11 AM on April 5, 2007

It only works if I've thought about when I'll have to get up, the evening before. It's quite uncanny.

I use to be able to do this: glance at a clock while going to sleep and concentrate on the time I wanted to wake up. It would work with a error margin of +/- 15 seconds or so.
Can't do it now, alas.
posted by signal at 9:13 AM on April 5, 2007

Oh, something I didn't mention that is probably very relevant is that a result of my time working as a DJ I also acquired a sort of time fetish. This was an AM station with hourly satellite AP news I talked into and out of. This was 1982-1983, so knowing the exact time to the second was a new and rare experience. But I also got ahold of a shortwave and discovered the time frequency on it during that time. Since then, I've always cared a great deal about having all my watches and clocks set to the correct time to the second. I've used SNTP tools since 1994 and dialing up and using SLIP. My last two watches set themselves via the NIST time frequency, and I have several other clocks that do, as well. I think all clocks of every kind should do this.

Anyway, I suspect that this fascination with the exact time probably has something to do with my increased time sense relative to what I remember from when I was younger. I don't sleep that well and it's possible that I'm waking up and looking at the clock more often than I realize. If so, it's no wonder I wake up without an alarm.

I have a self-setting clock that displays the time and temperatures (indoor and outdoor) as a projection onto my ceiling in my bedroom. It makes me happy.
posted by Ethereal Bligh at 9:19 AM on April 5, 2007

EB: Keep in mind that color vision is synthetic, it doesn't reflect reality


I don't know why people think color is any different from sound, taste or smell. sounds and tastes really exist, so do colors.

The way the machine (a person) measures colors is a little eccentric but so is the way we measure sound and taste. Of course these are all real things we are measuring with our senses.
posted by bhnyc at 9:20 AM on April 5, 2007

All of us can see ultraviolet light. It's just that the lens blocks it. This is a good thing because UV light causes cancer. It's also harder to focus due to chromatic aberation. Apparently people that have had their lenses removed and not replaced see it as lilac.

We can all also see polarized light slightly.
posted by euphorb at 9:47 AM on April 5, 2007 [2 favorites]

color vision is synthetic, it doesn't reflect reality

these are all real things we are measuring with our senses

A loud, more energetic, sound does sound loud.

"Cool" blue is more energetic than "hot" red.
posted by StickyCarpet at 9:48 AM on April 5, 2007

my point expressed another way is-

reality is what we can measure. a properly calibrated machine will measure color the same as we do (and we are an example of that machine).

whether color inspires us to poetic descriptions of hot and cool doesn't diminish it's reality. maybe because of black and white photography we think somehow that colors overlay reality when it's as real as any other physical thing.

anyway sounds can be hot and cool without regard to energy, ask any musician.
posted by bhnyc at 10:28 AM on April 5, 2007

correction: as real as any other property of a physical thing
posted by bhnyc at 10:31 AM on April 5, 2007

I would just settle for people not using the word "hack" so much. Give that tired word a rest, please.
posted by Muddler at 10:32 AM on April 5, 2007

"I don't know why people think color is any different from sound, taste or smell. sounds and tastes really exist, so do colors."

No they don't.

"The way the machine (a person) measures colors is a little eccentric but so is the way we measure sound and taste. Of course these are all real things we are measuring with our senses."

Color vision isn't just measuring wavelength, which is something real, but we experience that measurement with a set of ranges and their combinations as qualitatively distinct from one another, which isn't anything real.

Contrast this to hearing: if you hear a frequency of X, and you hear another frequency of X/2, and then another of X/4, you perceive those as being the same sort of thing but quantitatively similar distances apart. If you do the same thing with light frequencies, then depending upon where in the visible spectrum you start with X, you will often find that X/2 and X/4 are not quantitatively different (different shades), but entirely different colors! Yet, those light waves are exactly like sound waves in that they only differ from each other by frequency. There are no colors in light just as there is nothing equivalent to colors in sound.

But there could be! We could perceive sound similar to how we perceive light. Or vice-versa. Our ability to discriminate different frequencies of sound comes from a huge number of distinct structures designed to each be sensitive to a particular frequency. When there are numerous signals, they aren't combined to produce a synthetic perception—we perceive each frequency seperately. We hear a tri-tone chord as three seperate tones. In contrast, with color vision, there are only three distinct structures which are sensitive to three ranges of daylight frequencies. Rather than perceiving those three as three different values of the same thing (as we do sound), which would provide us with three different shades of a single "color", and instead of merely interpolating the combination of those signals to get many more shades of a single color (which is a possible alternative), what our brain does is to do the interpolation but tag those three ranges as things that are qualitatively different from each other. The light in those ranges are not qualitatively different from each other, they're only quantitatively different.

So why in the world does our brain add this invented information? Because it's very useful. That qualitative distinction is just another way of saying that an X kind of difference is much more important than a Y kind of difference. That is, the X difference is the difference between two colors while the Y difference is the difference between two shades of the same color. We perceive both, and in reality there is only shades that are different, but the added information highlights a difference above and beyond the difference we perceive between shading. Why is this useful? Because those distinctions happen to correspond to ranges of colors that it's very useful in our environment for us to quickly and easily recognize as important.

Our perceptions of taste and smell are also real and not synthetic because the distinctions between different tastes and and different smells correspond to various different molecules. A better example of what you're claiming is our experience of hot and cold. We experience those as qualitatively different, and indeed we have different sensory apparatus for each. On the other hand, we're not actually sensing temperature, but rather we sense rate of heat transfer. Because in one case the transfer is in one direction and in the other case the transfer is in the other, then you can make a good argument that the two are qualitatively different and our perception that this is the case accurately reflects physical reality.

On Preview: "a properly calibrated machine will measure color the same as we do"

No it won't. This is why a color digital camera isn't a spectrometer.

Think about people who are color blind. They can (to a degree) distinguish between two frequencies of light that normal people perceive as different colors (they'll perceive them as different shades of the same color). So they are perceiving the distinct wavelengths, which reflects a real, physical difference. What they aren't seeing is two different colors. We perceive, for example, red and blue as fundamentally different kinds of things. But they're not different, they're just different ranges of frequency of the same thing.
posted by Ethereal Bligh at 10:44 AM on April 5, 2007 [1 favorite]

Cool article. I wonder if/when these sorts of novel input devices will start hitting the market or when people will start creating their own versions at home. That compass belt doesn't sound too complicated, though the tongue electrode array is probably out of the question... for now.

"One of my long standing fears is that some sort of direct brain-computer interface will be invented, and my brain will be too old to learn how to use it..."

Me too, but it looks like it won't be such a problem, at least for output. Apparently it only took Matthew Nagel a few minutes of training before he was able to use his brain/machine interface to send email and do other tasks.

One thing I've been wondering about is: if you had a chip in your brain that could stimulate your brain as well as read signals from it, and it was connected to a computer running an artificial neural network. Could you think using the machine?
posted by benign at 10:57 AM on April 5, 2007

color vision is synthetic, it doesn't reflect reality

Color is our way of perceiving the wavelength of light. In that sense, color is manufactured by our brain. The wavelength is real, but there is no reason that light with wavelength 475 nm is blue what we perceive as blue, that is entirely abitrary.

The same can be said for other senses. There is no reason that little molecules floating around in the air need to be smells, that is again just the way we percieve them. Consider sound, it's just air vibrating. Other critters use this as vision. For (seeeing) people, it's sound.

I think saying none of this reflects reality is kind of misleading. All of it reflects reality, it just reflects it an arbitrary way that seems to work well for us.
posted by !Jim at 11:20 AM on April 5, 2007

The wavelength is real, but there is no reason that light with wavelength 475 nm is blue what we perceive as blue, that is entirely abitrary.

This is misleading, but I understand what you are trying to say. In fact, there is a reason that we perceive particular wavelengths as particular colors, but that reason is found in the brain (or mind, perhaps) as opposed to the wavelength of the light.

To say that the relationship is "entirely arbitrary" is, of course, too strong.
posted by voltairemodern at 11:51 AM on April 5, 2007

ever since i was little i could find north in any city or location, even in a hotel room at night..
posted by xjudson at 12:00 PM on April 5, 2007

This is so exciting to me. What if having a text message caused a tickle instead of a loud buzzing or ringing? This is what I just applied to go back to school to do under the guise of Interface Design. That belt that lets you know which way you're facing while flying...why don't we have these things yet? I want to have new senses. I want to instinctively know things.

Why don't we build portable radar units and put them under soldiers tongues? or suits for proximity sensors in cars? So many chances for innovation.
posted by Brainy at 12:03 PM on April 5, 2007

This looks like a fun thread, but I have too much work to do to get really involved in the discussion. (Sucks.) So, I'm going to cheat and repost something that I wrote in another thread that I think backs up EB's position:

===

Humans, however, have the luxury of being able to learn to intellectually compensate for their vision, so someone who is colorblind may be able to guess from the context if something non-colorblind people see as red, is actually red.

I think this hypothesis is underplayed. Instead of saying that the colorblind "intellectually" compensate for their vision, and "guess" that the object is red, I suspect it is more correct to say that the colorblind subconsciously compensate for their vision and perceive the object as red.

The standard story about the conscious experience of the colorblind goes like this: we have three different types of photopigment in the cones in our retinas, and their outputs allows us to compute the three axes of our phenomenal color space (the axes are blue-yellow, green-red, and black-white). Dichromats, lacking one type of cone, can't process the difference between red and green. So they have only a two-dimensional color space.

However, dichromats can make perceptual distinctions between red things and green things by subconsciously using luminance information. Red things tend to be darker than green things. This is why black and white photographs "work". We evolved trichromacy extremely recently, and it probably evolved directly out of our abilities to tell differences in luminance. Our primate ancestors needed to see fruit amidst leaves, and could do so using luminance cues. It behooved evolution to find a more efficient way to make those same discriminations. (Alternately, some think that trichromacy evolved to let us distinguish young nutricious red leaves from older green ones.) Thus, mutations in the genome led to a new type of photoreceptor in the eye.

What's the reason for thinking that the trichromatic apparatus in the retina (the third cone) isn't simply a more efficient way of making certain perceptual judgments and having certain conscious experiences? It would be weird if such a low-level entry-point into the brain were responsible for a totally different plenum of color experience.

It's interesting to hear colorblind people talk about their conscious experience. Contradicting the standard story, many say that they do see red and green as qualitatively different colors -- they just often confuse them for one another. This is what would be expected if all they lack is an efficient and reliable mechanism for doing the exact same job. Roger Shepard has some neat experiments on this score. Also, many colorblind people don't realize that they're colorblind until a very late age. Wouldn't it be weird if they saw red and green as the same but never realized that they did?

If anyone's interested, Kathleen Akins and Kimberly Jameson are two fascinating researchers in this field. I found this paper of Jameson's, in particular, to be extremely thought-provoking.

===

(Also, I don't think it's true that there's just one tetrachromat out there who's been found. I was under the impression that tetrachromacy was relatively common. Also note that depending on how finely or coarsely you want to distinguish different "types" of cone (this will be somewhat arbitrary, like drawing distinctions between species), many of us are pentachromats, hexachromats, etc. (cite: Neitz, M., & Neitz, J. (1995) Numbers and ratios of Visual Pigment Genes for Normal Red-Green Color Vision. Science, 267, 1013-1016.))
posted by painquale at 12:13 PM on April 5, 2007

> "Cool" blue is more energetic than "hot" red.

I've always thought the blue=cold, red=hot association was a little weird. In drawings it can make sense only in that something symbolic like ice (something cold) can appear more bluish than a typical reddish flame (something warm).

However, when I look at say, a brand new LCD computer display that is blasting out way too much blue, I can't help but think it's too "hot" or too strong. A display that is too reddish seems "weak" to me.
posted by Potsy at 2:15 PM on April 5, 2007

Red has all kinds of special perceptual emphasis, to my mind probably related to the need to react with emphasis in cases when you or those around you are being bloodied.
posted by StickyCarpet at 2:34 PM on April 5, 2007 [1 favorite]

Plasticity with regards to vision is demonstrated by many people who wear "bifocal" contacts. One eye uses a reading lens, while the other uses a distance lens. The brain learns to compensate rather quickly - usually a matter of days.
posted by Benny Andajetz at 2:48 PM on April 5, 2007

It didn't feel bad, actually — like licking the leads on a really weak 9-volt battery.

So alternate vision tastes like...

Yikes.
posted by vytae at 2:56 PM on April 5, 2007

Seeing in the near ultraviolet as well as visible range might be distracting and unpleasant, rather than the trippy image of seeing colors that humans have never seen before or imagined.

Cloth and detergent manufacturers routinely use ultraviolet dyes to "brighten" whites and light colors. This is why people's white shirts glow an eerie brilliant purple under black (ultraviolet) light. Other objects also fluoresce unexpectedly.

We usually observe black light effects in darkness (in the visible band). With near-ultraviolet vision added to the visible spectrum, the effects might be even weirder.
posted by bad grammar at 5:31 PM on April 5, 2007

Eideteker said:

"The brain is far more plastic than we commonly realize."

Speak for yourself!

You bolded the wrong word there, bud. Read it this way:

"The brain is far more plastic than we commonly realize."

You're just uncommon. :)
posted by Malor at 12:16 AM on April 6, 2007

joe's_spleen: To develop weird arse-telepathy, you need to move to Japan.
posted by eritain at 1:35 AM on April 6, 2007

Thanks for the thoughts. Wish one got special neurological/visual prowess staring at the monitor reading.

eritain, Enjoyed the weird arse-telepathy site! :)

Visual acoustics. Color of my sound.
posted by nickyskye at 8:20 AM on April 6, 2007

Red has all kinds of special perceptual emphasis, to my mind probably related to the need to react with emphasis in cases when you or those around you are being bloodied.

I think you're right, StickyCarpet, and I think the reaction is mainly a tendency to faint at the sight of it (think how many accounts you've read of people playing dead to survive a massacre to understand the selective advantage of this, or of the value of shock in keeping you from losing too much blood through a superficial wound).

I also guess this is the reason so many athletic teams have blood-red uniforms: by evoking the fainting response (partially) in your opponents you reduce their ability to compete, but you are not affected because long exposure has taught you to overcome your reaction.

I know two unrelated women I believe to be tetrachromats, based on their color abilities and certain kinds of color-blindness in the appropriate branches of their family trees, and the major advantage they seem to possess is perfect color pitch-- in other words, they can tell you if a color you are looking at in your house is exactly the same as the one you saw at the store as well as you could (I could, that is) by placing the two objects side by side.
posted by jamjam at 1:34 PM on April 6, 2007

Speaking of tetrachromatics, I've read that to create a color space in which one can reliably find other colors that are perceptually equidistant requires four primary axis. The Munsell color space only does that for colors of equal luminosity. Sorry can't find find the citation, call me out on it and maybe I'll get angry and search till I find it.
posted by StickyCarpet at 6:12 PM on April 6, 2007