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Neural Coloring In: How The Mind Sees Color
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."
A few years a ago it was mentioned that by wearing two differently coloured lenses some colourblind people were able to see colour again. I tried
a web search on it but it did not came up with anything... does anyone remember that story?
So am I. Could barely make out a vague "S" shape in that article. Had a hell of a time w/ the resistors in physics lab. Most people's concept of color is rather arbitrary as I like to point out to them. Here's a example:
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!"
In different cultures, the colours are defined differently, and this makes translation very dificult.
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.
C over Lambda, of course.
-- Could you use my software consulting serv
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.
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.
As recognized combined colors work for all (most) people (blue and yellow form green universally), the only possibility is that color wheels could be rotated. You call orange what I see as green, but my yellow and blue would then have to translate as your red and yellow, respectively.
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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
Even the samurai
have teddy bears,
and even the teddy bears
get drunk
And finally, for anyone that had their hopes up like me, it seems the friendly people at ColorMax were lying about what their glasses could do (iirc, they basically claimed to have a [very expensive] cure for colorblindness)
-- It is too late for the pebbles to vote, the avalanche has already started.
I'm so insightfull baby!
PCXL Forever!!!!
the amazon link is here
I had him confused with Thomas Szasz by the similiarity of sound in the names.
"It is a greater offense to steal men's labor, than their clothes"
I think that's one of your standard triping-out-on-drugs thoughts, along with "how can the universe be inifititely big, but then if it isn't, is there like a wall or something? whoa...." and "are there anymore brownies?".
- isaac =)
Yeah, i know what you are talking about, about training the mind to see colors better. Over the years i've become much more adept at differentiating colors. When i was a little kid i could only vaguely tell the difference between the primary colors, but over time i've learned to notice the subtle shading differences (how bright or dark they seem from red, blue, green) between colors, so now i can "see" color, almost. If an object is of a good enough size that i can see light reflecting from it from different angles i can judge its shade, and i can tell you its color--but those damn little dots on color test are too small so i can't tell there shade well enough. Interestingly enough, if someone points out to me the pattern i'm supposed to see i can stare at it a little while and finally see the color difference and the pattern appears.
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.
A highschool classmate of mine was totally colourblind. She only saw black and white because due to an extremely rare genetic defect she had only the light sensor thingies that see black and white, not the ones that distinguish colour. (Sorry about that, I don't know the English word for those things. I mean what's known in Dutch as "staafjes" and "kegeltjes" respectively). This had a few interesting side-effects, though. Even though she saw no colour whatsoever, she had an extremely sharp vision, somewhere in the range of 5-10/20, and she could discern most colours by grayshade. If you gave her a black and white picture, comments like "wow, that's a nice purple dress" weren't uncommon. She had her own pencil set with the colours written on them. After doing some research to find out which colours looked exactly the same to her, we had a brief period of great fun swapping stickers around - luckily she could laugh about it too, though our art teacher couldn't *ouch*.
)O(
Never underestimate the power of stupidity
Never underestimate the power of stupidity
To err is human, to moo bovine
I recently did a scultpure that utilized the tricks that Edward Land did... if you don't know about Land's experiment, you should. It's an eye-opening (sorry) experience.
:)
Check out a write I did he re. View a short animation that explains it all here (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.
Complexity Happens
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.
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 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.
-- Could you use my software consulting serv
I've always wondered about this: Could different people see a thing, and know it is, let's say, red, but in fact be seeing a different colour? It's a concept i find hard to explain to other people but basically I'm wondering if two different people could perceive a colour of the same name in two different ways? Has anyone else wondered about this, or is it just impossible and I should stop wondering?
Really, color is a subconcious phenomenon and is totally subjective. We have NO way of telling if I see "blue" the same way you do - since blue is just a name given to a common decision for the color of an object. Had this been called "blah" when you were growing up, it would have made no difference, IF the people who taught you your colors (your parents most likely) agreed upon objects whose colors where blah or were associated with blah. When we think red, we usually think apple and blood, but my eyes might SEE something totally different than yours. The only way to find out would be to put your eyes in my head. And that is very difficult if possible at all with today's medicine. So, we don't really know if colorblinds are really colorblind - their spectrum might just be tuned to a different range. Most humans see more shades of green than any other color. Other colors like orange might look the same even if the wavelengths of light are different from two different oranges, so we are more tuned to green. But maybe the "colorblinds" are more tuned to another spectrum, like grays? They might be able to see more shades of gray than anyone else. Or maybe IR - wouldn't that be nice? Other animals can "see" IR, maybe we could too.
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.
-Leo
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.
"It is a greater offense to steal men's labor, than their clothes"
trichromatic theory: this is what most people are familiar with, three types of cones sensitive to red green and blue. This is a little misinformed. There is only one "type" of cone, and different cones are receptive to different wavelengths (440, 530, and 560 nm are the peaks of sensitivity for the three types of *rhodopsin* in the cones).
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
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