Neural Coloring In: How The Mind Sees Color 78
fluppy88 writes "Beyond 2000 has a very interesting article about how the mind interprets color. Scientists in Australia have developed a mathematical model for how the brain sees color, and believe their discoveries could eventually be used in bionic vision-type devices to cure color-blindness, among other things."
Coloured contact lenses. (Score:2)
a web search on it but it did not came up with anything... does anyone remember that story?
25 years of research... (Score:1)
nf
nf
Re: I'm slightly color blind (Score:2)
I see "green" stoplights as PURE WHITE, whiter than car headlights. Most people call these "green" lights, and they also say that grass is "green".
What's intriguging is that the light that comes from grass & that which comes from "green" stoplights MUST be different, because I can distinguish them. (Spectroscopic analysis would confirm this.) So from my perspective non-colorblind people have a difficency because they use the same word to describe two "colors" which are clearly distinct to me. (even though, if pressed they admit that they are different shades of green)
I'd prefer to skip these arbitrary definitions, & just say, for example, "Hey, I really like your lamda = 750 nm dress!"
Re:It's all relative (Score:2)
Eskimo, for example, have three colours.
1) red -> orange
2) yellow-orange -> yellow
3) green-yellow -> violet-blue
Eskimo have no regular words for violet-red's and strong violets
Athapaskan have four colours
1) violet-red -> yellow-orange
2) orange-yellow
3) yellow -> violet-blue
4) blue-violet -> violet
The only absolute thing about colours is that we all have RGB cones in our eyes, which are centered around the greens in vegitation, which are centered around the max intensity of sun light that gets through our atmosphere.
Superman, being from a red sun system, if he is anything like a human, would have IRG (soft? infrared, red, green) cones; and everything that we see as red and green, he would see as green and blue.
I suppose that attempting to imagine more than three colours is just as difficult as is more than three geometric dimensions.
But enough rambling, red is red is red, a specific wavelength on the spectrum. And red is not the experience of red; experiences are finite and distinct, red is not, it is red, as is defined.
What's New? (Score:2)
C over Lambda, of course.
Article misarticulates the point of the research (Score:2)
Now the wavelength is very, very important to seeing color. As an example from a typical elementary school science class if you take a clear green sheet of plastic and you looked at green apple, the apple looks green as you expect. But with that same sheet of green plastic if you looked at a red apple, the apple will look black. The green sheet of plastic absorbs all wavelengths of light except green. Does your brain compensate? It can't help but see that red apple as black.
What is the interesting part of this article is the fact that the brain while does not compensate for the gross abnormalities such as black apples, it does actually adapt to colors if the colors are in the visual field long enough. It is not an adaptation that is unique to vision though. Have you ever entered a room that smelled peculiar? After a short while you probably couldn't notice it anymore. The brain is adapating to filter out the constant information if there is no change in inputs. The brain apparently requires contrasts for optimal perceptions.
Take the eyes for example and the Gestalt principles. Our best perception occurs when there is a contrast between stimulations. Microsaccades (small involuntary eye movements) seem to be involved in the contrast perception so that we can resolve contrast easier. If we are stationary and the environment is stationary, without our eyes involuntarily moving we would have a very difficult time resolving anything.
BTW all this should have been covered in Freshman Psych 101.
Red + Green = Yellow (Score:1)
Re: I'm slightly color blind (Score:2)
I'd prefer to skip these arbitrary definitions, & just say, for example, "Hey, I really like your lamda = 750 nm dress!"
Hmm... colour is NOT the same as wavelength.
For instance, that dress probably won't reflect just one wavelength, but is more accurately described by a reflectance function of the incoming light spectrum, still we say that it has ONE colour. The reflected wavelengths would also change, for instance when you go indoors/outdoors. So your lambda would change although the dress stays the same. A green dress is always green, and most of the time (due to colour constancy) it also looks green. Colour tells more about an object than the reflected wavelengths do.
I saw an experiment on this (Score:1)
My friend did a few experiments with color paper just to fuck around with a few of us (and he needed something for school). What he did was cut out a small piece of colored paper, and while we had our eyes closed, he would stick it almost directly under our eye. When we opened our eye, we had to identify what color it was. The funny thing was, you'd almost ALWAYS identify the opposite color on the spectrum. For instance, when I had a piece of black stuck under my eye, I identified it as white, and when my friends would have green stuck under their eye, they'd see red. It was quite odd and I really didnt understand how it worked, but maybe someone on
-Bongo
Yes, But Not Randomly (Score:2)
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Re:Something i've always thought about.... (Score:1)
A distinct type of blue is a distinct wavelength of light.
Nope. A distinct type of blue can correspond to many different reflectance spectra. Reflectance functions that appear the same to us but are different are called metamers.If you have a solid color object, only one wavelength of light will be reflected from that.
Not necessarily. Brown, Purple, Yellow etc are also colours, but they correspond to several wavelengths.
well... (Score:1)
Great Essay by Oliver Sacks (Score:2)
In the first essay Sacks writes of a 65 year old painter who has an accident and finds out he is completely colourblind. To add to the frustration of not seeing in colour, he cannot even think in colour. The patient found that colourful objects were unpleasant and sometimes glaring. Also, since the man was a painter, this problem was of great importance. Sacks creates a great portrait of the trials this man must endure due to his curious affliction. He delves deep into the psychological impacts on the painter and medical knowledge on other, similar cases of colourblindness. He also presents copious amounts of medical information, but in an easy to understand manner. Pick up the book, it is a fantastic read and there are picture comparisons of the colourblind man's paintings before and after the accident. The book also contains six other essays with regard to other medical phenomenon, and Sacks is a fantastic writer!
Even the samurai
have teddy bears,
and even the teddy bears
Re:It's all relative (Score:1)
ANYway, colorblindness is just a subjective idea!
To a philosopher maybe. But you could always have your eyes examined and find out that it is for real :-)
The colour sensitive cells in your eyes (red, green and blue cones) can be distinguished nowadays. If you lack one kind of cone you have to be colourblind. There are also objective tests that check if you can distinguish colours, there even was one in the article. If you cannot distinguish between, say red and green, you are per definition colour blind as well.
Re:Something i've always thought about.... (Score:1)
Colorblindness (Score:2)
And finally, for anyone that had their hopes up like me, it seems the friendly people at ColorMax [color-vision.com] were lying about what their glasses could do [fda.gov] (iirc, they basically claimed to have a [very expensive] cure for colorblindness)
modelling scientific phenomenae (Score:1)
the biological process of decerning colour is one thing. yet, the brain's process for interpreting these signals is another matter entirely. one could take the dual-colour approach, or the tri-colour approach, or any other and quite easily model them into a perceptual system which could be hardcoded into a series of chips or just tested in a simulation.
these tests do not add any credability to said assumption other than giving some more evidence either for or against a certain perceptual model.
the mentioned article tells about a model of a rather specific perceptual model and should be seen as such, an experiment in human cognition, nothing more.
Re:Great Essay by Oliver Sacks (Score:1)
Sacks has actually written a book on colourblindness called "The Island of the Colorblind". I haven't read it, but I saw an excellent documentary [achromat.org] about it.
It's about an island full of totally colourblind people (achromatopiacs?). It was fascinating.
Re:I'm slightly color blind (Score:1)
Resistor color codes - you know Victory Garden Walls - are just unfathomable to me.
Victory Garden Walls??! Sounds like you had a sissy shop teacher. :-)
The correct colour code memory aid goes thusly:
Bad Boys Rape Our Young Girls But Violet Goes Willingly
My first year electronics teacher (I took grade 11 electronics in grade 9) taught us that way, and I've heard it from almost every old fart electronics guy (teacher or no). The new ones teach you something like "Better Be Right Or Your Whole Big Venture Goes Wrong" or some such namby-pamby thing. :-)
Impressionism (Score:1)
It made me realize how much we take for granted the amount of post-processing our brain does to extract information from our eyeballs' visual color signals.
Re:Something i've always thought about.... (Score:2)
Oliver W. Sacks? (Score:1)
anyway, the book is called "The Island of the Colorblind and Cycad Island", by Oliver Sacks (the guy who wrote The Man Who Mistook his Wife for a Hat)
adrien cater
boring.ch [boring.ch]
Re:Oliver W. Sacks? (Score:2)
the amazon link is here [amazon.com]
I had him confused with Thomas Szasz [amazon.com] by the similiarity of sound in the names.
Re:Something i've always thought about.... (Score:2)
- isaac =)
Re:Something i've always thought about.... (Score:1)
I guess what I'm trying to say is that what I see as something isn't exactly the same way you see it.
Another good example, and this one is a little clearer for an example, is hearing. The way you hear yourself when you talk isn't the same as others hear you. A good way to illustrate this is to record your talking or singing or whatnot, and then play it back. Everyone will say you sound exactly the same to them. However, you hear yourself in a totally different manner than you do in livetime.
Anyone wanna clear up on that?
I can't really describe in the most accurate words what my theory is actually.
Re:Something i've always thought about.... (Score:1)
You are not the first person to wonder about this; in fact, it's usually the first tangent followed in the traditional "If a tree fell in the woods" discussion in freshman philosophy classes the world over.
Re:It's all relative (Score:1)
Umm, isn't that same thing?
I'm (somewhat) colorblind, and playing Super Puzzle Fighter is a bitch! Maybe i can see more types of orange or something, but that's not much of a consolation when I'm getting the mega block smack down.
- Isaac =)
Re:It's all relative (Score:1)
But enough rambling, red is red is red, a specific wavelength on the spectrum. And red is not the experience of red; experiences are finite and distinct, red is not, it is red, as is defined.
There is one slight problem with this definition of red. You cannot tell if something has a certain wavelength unless you use a spectrometer :-)
Since I don't want to buy one I will keep refering to my subjective experience of red as red.
Color is even more important than you think.... (Score:1)
If you want to try the test yourself you can do so at ColorQuiz.com [colorquiz.com] and I can assure you it is incredibly accurate (or at least it was for me and everybody else I know who has tried it). There is more to how color is interpreted in the human brain than I think a lot of people appear to be making out. Anyway, just my 2 cents....
What you're supposed to see in the circle (Score:1)
Upon hearing that he couldn't see anything in the field of dots, I promptly grabbed the "tint" knob on the teevee and twisted it back and forth. "WAIT! I SEE IT!" Sez he.
Try it sometime, if you're one of the affected individuals. You could probably do it with that image on the webpage and the GIMP or photoshop... just mess with the hue of the picture until the "8" appears.
Re:I'm slightly color blind (Score:2)
I was always told that color blindness was caused by some sort of difficiency in the rods and cones of the eyes, but i never really believed it--i always thought it was a defect of the brain and still do (at least for partial color blindness). If it were simply an ailment of the eye, how come i can see more colors now than i could 20+ years ago? I've also seen the odd effect that when looking at a convex bicycle mirror i can see not only a slightly distorted image, but damn near perfect color (as far as i could tell)--the mirror seemed to stretch out the differences in shades somehow and i could interpret the colors properly. I doubt that a defect in the hardware of the eye that differentiates colors could be cured by such a thing, but a tweak like that could work if it was the software of the brain that was misinterpreting a signal from the eye.
Colors can be randomly swapped (Score:1)
if you mix the color named 'blue' with the color named 'yellow' you get the color named 'green'.
although this statement may be true for (nearly all) people it has nothing to do with the colors those people see.
More general than vision (Score:1)
Re:It's all relative (Score:1)
Daniel Dennett says no, (I think) (Score:1)
I wondered about the same thing when I was about ten, and remember discussing it with friends and they had wondered about it too. Many of the posters here had the same thought. Dennett says this same thought occurs to a surprisingly large number of people.
Re: I'm slightly color blind (Score:1)
Or is color constancy an entirely psychological effect? So if this green dress is lighted by orange sodium street lights, are they saying that the brain identifies the dress as being green because it adapts it's color table to the ambient lighting or is it that the brain knows and understands that the dress is green but it only looks different because of the ambient lighting. If I look at a white paper under an orange light, the paper looks orange to me and from what I can tell, it is a much high mental process that must consciously realize that the paper is white even though it actually is reflecting orange light.
Colour Constancy (Score:1)
From what I've read, the colour constancy phenomenon depends both on low-level adaption, and higher cognitive skills, such as remembering colours of objects, inferring that a certain patch of colour is shadowed etc.
Sorry, but I'm afraid I'm far from being an expert on color constancy. It's an interesting phenomenon though :-)
The Ishihara tests aren't the only ones (Score:1)
I have a so called "severe colour discrimination deficiency". About 5 years ago I took a colour test in high school where I was presented with many black cards, each had three small dots, I had to say whether the left dot or the right dot was most similar in colour to the centre one. Because they aren't exact matches, this was extremely difficult for me.
Usually I rely on viewing colours from many angles in different lights to work out what they are. But, this text used small dots which prevented me from doing it. I'm not entirely sure, but I think that I can do some of the Ishihara tests by holding them in coloured light.
PS, I posted this /. submission on colour-blindness first :-P
Re:Something i've always thought about.... (Score:1)
Brown, purple and yellow all (can) have complete saturation (e.g. there is no grey in there). Therefore, they can be "pure" colours, consisiting of only one wavelength. The whole world is not an RGB monitor.
Sorry, you're partly right. Yellow is a spectral colour. But, show me a spectrum that contains brown or purple :-) Purple is the text-book example of a colour that does not correspond to one single wavelength.
Re:I'm slightly color blind (Score:2)
)O(
Never underestimate the power of stupidity
Check out Land's Experiment - trippy stuff (Score:2)
Check out a write I did he re [finearts.uvic.ca]. View a short animation that explains it all here [finearts.uvic.ca] (Shockwave required).
Another really trippy experiment to try is this:
Grab a friend and go to a mirror. Then have your friend face you, and look at your eyes (one and then the other). Then look into the mirror at your reflection, and look from one eye to the other. Notice a difference? This will freak you out.
Email me if you want to know whats going on.... I dont want to spoil it, its too freaky.
Re:25 or so years of research (Score:1)
Two people can indeed see the same color different (Score:1)
Re:More general than vision (Score:1)
25 or so years of research (Score:3)
Has anyone seen the clips of that guy who went blind some 30 years or so, and has been taking part in neural experiments for the past 25 years? Last I heard, he can now see outlines of images, kinda like a really bad emboss filter. I wonder if they can hack some code up for his implant to make this guy see. It'd only be fair to get it to work for him as he has devoted years to the cause.
I'm slightly color blind (Score:3)
There are circles filled with lots of colored dots and you're supposed to be able to see figures in the dots.
I didn't know I had a problem before then, but since it was pointed out to me I notice it sometimes. Broad fields of color are easily distinguishable, but if you make small dots of red and green next to each other with felt tip pens on a sheet of paper, I will have trouble telling them apart.
I can easily tell that they are of different colors and one is red and one is green - but which is which is hard for me, and as I stare at them they switch color.
Resistor color codes - you know Victory Garden Walls - are just unfathomable to me.
On the other hand, I am an artist [geometricvisions.com] when I'm not programming (not much there at the site yet) and I particularly like oil painting; if I paint a lot for some period of time my color perception gets much sharper. If I spend all my time just programming it gets dulled.
Re:25 or so years of research (Score:1)
Something i've always thought about.... (Score:2)
It's all relative (Score:2)
ANYway, colorblindness is just a subjective idea! The might be able to see the most brilliant UV, but our "red" and "blue" might seem the same.
Re:Something i've always thought about.... (Score:1)
A distinct type of blue is a distinct wavelength of light. If you have a solid color object, only one wavelength of light will be reflected from that. Whether or not our minds interpret that color the same is irrelevent, though it's probable. We both are seeing the same blue.
Re:Something i've always thought about.... (Score:1)
That everybody perceives differently is very obvious when you start noticing it. My father has trouble telling colours apart when it's rather dark, and my girlfriend will have trouble seeing the difference between orange, pink, purple and red under similar rather low-light conditions, which becomes very obvious as we shoot some pool every monday and tuesday evening. I sometimes have trouble telling certain shades of blue and green apart. Another friend of mine has extreme difficulty telling two tones apart if they're exactly one octave from eachother. Another example is that somebody who's cross-eyed doesn't see a double image. Their brain has adapted to the defect just as it would have adapted to correctly positioned eyes and will generate a correct stereoscopic image, though ofcourse not with the same field of vision.
My conclusion is that everybody does see differently, but we've invented a protocol (language) to be able to communicate with eachother.
)O(
Never underestimate the power of stupidity
Human Photoreceptors (Score:1)
The two types of photoreceptor cells in the human eye are called rods and cones due to their shape. Rods are sensitive enough to respond to a single photon, but together they create only one coarse, gray image, which is just adequate for seeing in poor light. Fine detail and color come from the cones, but they need a lot more light.
Regret for the past is a waste of spirit
We can't get all of the visible wavelengths (Score:1)
Re:Something i've always thought about.... (Score:1)
I had a dream similar to this once. Some guy had found a way to see a *new* colour. In the ultraviolet range I think.
I was about to put on the goggles and see this wondrous new colour and I woke up.
Damn
Answers the Science bit, not Philosophical (Score:1)
Re:Something i've always thought about.... (Score:1)
I'm sure you could really mess up children though, teaching them the wrong color names for different objects. They'd be real confused when they came into contact with children taught the traditional color names. I can almost hear the arguments now:
"Nun uuuuh! It's not red, it's green!"
Re:25 or so years of research (Score:2)
"25 more to go" is right. We may now know that the brain does things via contrast (although I think that's been strongly suspected for a while), but it's a long way from there to developing accurate vision algorithms, implementing those in hardware, designing an appropriate electrode array and a protocol for implanting it, doing animal trials, and then finding humans willing to be the first adopters. (Would you really be willing to let me implant an untested-in-humans device into your brain just to move from grayscale to color? Keep in mind that if the device does something bad, it could permanently damage your vision.)
Traffic lights and color blindness (Score:1)
Origins of color blindness (Score:5)
Originally all animals who had color sight had four colors sensors, corresponding to red, green, blue, and ultraviolet. (I do not recall the exact bands) You see this to this day in animals like birds, etc.
Mammals went a long period with color sight while also being creatures of the night. This caused some to the sensors to change or be lost. We arrived at having night vision sensors, as well as red and blue, losing the ultraviolet.
Fast Forward to a point where our ancestors went back to being creatures of the daylight. Green was desirable, and this was done by the split of the red sensor into two bands, which gives us the red green confusion. This has the end result of color blindness when the conditions are right. Obviously there is a gradient scale of color blindness.
As a side note, I recall a special series on PBS in the past few years about different aspects of the mind, written by Dr Thomas Szasz (sp?). One of the episodes was about this island in the pacific where a large portion of the population was color blind. This was due to a peculiar history of natural disasters that resulted in alot of inbreeding. The people had very sharp vision, were very sensitive to sunlight, and were totally color blind. They flipped out over sunglasses, adoring them totally.
The effect in sight was described as similar in the time of twilight when you can still see well, but the color has been leeched for your view. Although they make up for color by the attention to textures, shades, and shadows.
Interesting over-all ...
One of the problems of this discussion comes up in the various color model theories. It is educational to compare the common Red-Green-Blue model vs Hue-Saturation-Luminance model. There are other models used as well, well known by graphics art specialists.
Re:Something i've always thought about.... (Score:2)
IIRC, there's an urban legend that ingestion of LSD cures color-blindness, so you may not be too far off the mark. Since color perception is something the brain dynamically creates and modifies according to the article, messing around with the brain using hallucinogens can (and does) make you see colors that aren't there. Whether this has any use in treating/studying color-blindness is questionable, but the experiments would be fun... :-}
FWIW, I'm slightly red/green colorblind, and the only effect I've ever noticed from it in the real world is that I can't tell the tan M&Ms from the green ones without examining them really closely. Color vision is not *quite* as important as we think, since most mammals get by with far less color perception than humans. Heck, I might be willing to live with B/W vision if I could see in extremely low light like a cat....
Re:Something i've always thought about.... (Score:1)
Re:Coloured contact lenses - due to the 3D effect? (Score:1)
theories of color vision (Score:2)
opponent process theory: here we have the idea that receptors are formed in pairs (red/green, yellow/blue, black/white). This theory is supported by the anatomy in the retina (ganglion and bipolar cells) and in the lateral geniculate nucleus. Actually, this theory can be sufficiently modelled by neural networks and the anatomy. There are many experiments that support this theory.
dual process theory: this sort of combines the two above, and is the leading theory in vision science these days.
The point of all this is color vision is very hard to understand, and at the same time it's the one subject we know the most about regarding the brain and perception.
The previous post is incorrect in that the "red" cone is split into two bands. It is the "opponent" part of the ganglion and bipolar cell processing that gives us the duality between red and green.
there are two types of color blindness. there are people who are dichromats and there are monochromats. There are three types of dichromats, two that are red/green colorblind, and one that is blue/yellow. Monochromats perceive the world as degrees of lightness.
Kawaldeep
Re:Something i've always thought about.... (Score:1)
Hmm... I'll have to make sure there's a color blindess test thingie (with the little red and green circles) around next time and see if that's true.
- Isaac =)
Re:Something i've always thought about.... (Score:1)
is color blindness interesting? (Score:1)
Re:It's all relative (Score:1)
Other animals can "see" IR, maybe we could too
If you want to see IR, point a remote control at a camcorder. It detects it as light and you can actually see the the signal coming from it through your camera's screen like you would if it was a pulsing lightglobe or something.
Re:is color blindness interesting? (Score:1)
It's not a HUGE deal, but it can definitely be annoying. All too often in maps and charts graphic designers will use colors that have equal values (light/dark levels) and only different hues. If you are colorblind, it makes it very hard to tell the difference. The designers can fix this easily by using colors with differing values (as well as differing hues). And as another poster pointed out, those color codes on transistors are a pain! I have to carefully compare them to ones I know the value of.
It's not urgent, but if there was a relatively easy way to fix colorblindless, I'd be up for it.
- Isaac =)
Re:Something i've always thought about.... (Score:1)
uhhh... (Score:1)
they just cant distinguish between certain
hues.
there is absolutely no sense in making a gradual
transition (if one were available).
Re:Something i've always thought about.... (Score:1)
That is probably not the best of things to say to one who is going to study Philosopy of Science, Technology and Society (after trying Computer Science and finding it way too dry). Philosophy is definitely not a waste of everybody's time.
For example, take the sociological impact of computers and most notably the Internet. People who know sociology generally don't know much about technology, and people who know a lot about computers an the Internet don't know the first thing about sociology. Would you want either to answer questions about the Internet's impact on society to, for example, politicians? The former wouldn't understand the technology, the latter wouldn't understand the scope of the impact, and wouldn't be understood by the politicians, with crackpot bills like CDA, COPPA and COPA as a result. A "technical philosophy" person would be able to answer such questions, though...
)O(
Never underestimate the power of stupidity
Re:Something i've always thought about.... (Score:1)
--
Re:Red + Green = Yellow (Score:1)
--
Colorquiz test fails the logic test (Score:1)
Well, reading the results I found them to be pretty true...but it occured to me that they seemed rather generic comments that could apply to anyone.
So I took it again, but this time I chose the colors in a random order. First by starting with my least favorite color then clicking them at random. Then clicking them in a pattern determined before the colors came up, so I would not have any "unconcious influence" on the pattern.
The data from those sessions seemed just as accurate...
So I'll have to give that quiz an "F"
Re:uhhh... (Score:1)
Re:Origins of color blindness (Score:2)
Matrix (Score:1)
Laine Walker-Avina
LaineW@technologist.com
Re:Something i've always thought about.... (Score:1)
As far as I am concerned, the colour you see probably isn't the same colour I see. The same would probably apply to other senses such as the tactile sense. When I hurt myself, would you feel the same pain? Probably not. I think the interpretation of our senses is pretty much a reflection of our upbringing. Look at languages for instances. Most of us comprehend spoken english without much thought, but once you start listening to someone that speaks an unfamiliar language, all you hear is jibberish, and the interpretation of your sense is lost.
What if someone magically gave you the power to see Xray? Your mind wouldn't be able to comprehend the data it's being given, and your brain would have to learn and figure out a way to interpret it. After such an experience, could you say to My and Your Xray visions are interpreted the same?