Naked Science Forum
General Science => General Science => Topic started by: neilep on 24/02/2004 21:53:19
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[:D]Has science devised a way for us to see through someone elses eyes yet ?...and if not...why not ?
People with normal vision seem to see the same colours, but can we ever be sure of subtle differences between shades and hues from one individual to another ?
For our American chums please feel free to change the spelling of colour to color.
Ta very much.[:X][:X]
'Men are the same as women...just inside out !'
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I think that most people with "normal" vision probably see the same colours- have you tried one of the colour tests with a number written in bubbles of slightly different colours? If our perceptions of colour differed too much, then many people would not be able to read those numbers.
Just my opinion. Hell- my, white could be your black!
"I have great faith in fools; self-confidence my friends call it."
-Edgar Allan Poe
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Color is perceived when photons of light of a particular wavelength are absorbed by the color-sensing parts of the eye called the cones. (and the transmission of the energy from that photon absorption is a signal sent to the optic nerve and then to the brain, of course) It's commonly accepted among the people who "decide" color that there is some very slight variation in perception of hues, (based on # of cones, I imagine) as the human eye can resolve something like 10 million distinct colors. But, barring a genetic defect like color blindness, rest assured that we're seeing basically the same colors.
This message brought to you by The Council of People Who Are Sick of Seeing More People
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I would basically agree with Jay that the machinery is very much the same person to person (barring defects) and thus we probably see the same color. Red is red. Blue is Blue. The argument may come in on subtle differences in shades of the same color. Just ask my wife - she'll tell you I'm wrong every time!
The same question could arise for hearing or any of the senses. This problem could be investigated further with the communication system I was proposing the other day where we could use an implanted device to send signals directly from one person's brain to another. That would eliminate the barrier of language.
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John
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Our appreciation of colour is entirely a construct of our brains.
There is no way to know whether the experience that I call "red" (produced by my brain when light in the red part of the spectrum enters my eye) is the same psychological experience that you or any other person (or animal) 'sees'.
We agree on the colour of things because that is what we have been taught - that when we see that colour it's called "red". But try explaining a colour to a blind person who has never had sight. You cannot do it except in metaphor. It is a unique and individual experience. My 'red' might in fact by your green.
Scary thought !
Chris
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx
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Identifying different colours is through learning. If you teach a child that the red colour we are seeing is called 'green' then every time he sees the red colour he'll say it's green. Although I don't think anyone would actually try this experiment, it will be so cruel to the child.
Angel
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Actually this "experiment" is done all the time. Our neighbors to the south call my Red "rojo" and Green "Verde". It's all just verbal symbols for some external stimulus. As long as we can agree what symbol ties to what stimulus we're ok. If not, we're speaking a different language and have something to learn. Right?
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John - The Eternal Pessimist.
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Thank you for all your valuable incites....I figured that it's a matter of accepting that each colour we see is most certainly the same as each other and that the possibility of differenes in shades and hues is almost a certainty....With regard to aural senses I can certainly vouch for vastly individual differences as I demonstrate quite specialist Hi Fi equipment and the subjectivity that each individual has is most obvious. I would presume as mentioned, this must also apply to all the other senses too. Thanks again
'Men are the same as women...just inside out !'
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But there are subtle differences in our perception of color (American spelling). For instance, when we get to the blue greens, I see the color as green, whereas most of my friends see is as bleu (French spelling, for Quantum), yet I am not color or colour blind. On the same subject, did anyone read "Island of the Color Blind" by Oliver Sacks? Fascinating book.
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Yes, but I'm making more of a philosophical point which is that the "experience" that my brain calls "green" - i.e. the way it responds to the presence of light in the green part of the spectrum - may be totally different to what another person calls 'green'. So what I call green might in fact be yellow in another person's head. But because we are brought up knowing this colour is green, that is what we call it. The experience that your brain generates for you when you look at something called 'green' may however, be totally different to that which my brain produces for me. But there is no way we can ever know !
Individuals with synaesthesia can appreciate what I am talking about (although I (sadly) don't have it myself). In this 'condition' there is presumably some mis-wiring in the brain that enables people with synaesthesia to, for example, taste shapes, hear colours or feel words, as well as experiencing them the 'normal' way that you or I do.
Chris
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx
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Chris, do you think that ESP could be a form of synaesthesia? You could "see" another person's thoughts, or "feel" their emotions.
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Now that is funky I can just imagine it...
"Would you like mustard with your hotdog sir?"
"Doesn't matter, as long as I say Circles it'll taste great!"
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just out of interest, how do these people hear colours? (would it be like photons stimulate the generation of electric impulse? very bad guess[:D])
Qing
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How can you 'hear' colour? I don't think there's any photoreceptor in the ears.
Angel
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Synaesthetics 'hear' colours because the nerve fibres that connect to the part of the brain that decodes sound also project (aberrantly) to the parts of the brain involved in colour vision. In this way when the synaesthetic hears a certain word, for instance, they also 'see' a colour because both brain regions are activated.
Chris
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx
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Do you think that could be part of the problem with autism? They are hypersensitive to touch. And there's a great book written by a high functioning autistic Temple Grandon called "I Think In Pictures." Maybe it's an exaggerated form of synaesthsia.
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what about they are seeing blue and meanwhile someone said the word "red",do they start to see it as blue or may be purple?
Qing
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i don't know it is hard to tell but bezoars idea sounds like it is ighly possible and it makes sence that autism could be an exaggerated form of synaesthia(i think i spelled that right). I guess tha it could be proven but how?
baby2michaelt[}:)]
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I wonder if young children have more ability to "hear" colors and "see" sounds etc. because the brain has more neurons and interconnections during childhood than it does after the person matures. My thought is that the extra connections Chris explains as synaesthesia exist normally in the young and then usually go away as a person matures but sometimes don't go away.
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John - The Eternal Pessimist.
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The additional neurons and interconnections in the brain must explain why teenagers know so much more than us dumb adults. Maybe I'll ask my 17 year old son.[;)]
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It's a nice theory John, but probably not correct.
Studies of the developing nervous system show that growing nerves are guided to the correct parts of the brain during embryogenesis and thereafter a process of 'tuning up' occurs whereby repeated use of those nerve pathways leads to a selective strengthening of appropriate connections, and the pruning of abberant connections. There is a critical period during early life when brains are at their most plastic. After this time the brain becomes much more 'rigid' and is less able to adapt. A kitten who's eyes are glued / stitched closed for 6 weeks after it is born will never see even though the brain and eyes themselves are completely normal - the problem is that the brain needs early visual input from the eyes to tune itself up so that it can process vision correctly.
The reason I don't buy your synaesthesia theory is that the regions of the brain that control vision and hearing are a large distance apart. There would not normally be abberant projections spanning such large distances. I suspect that in synaesthetics there has been an error in nerve navigation during development, or the failure of a certain population of nerve fibres to die leaving vestigial weak connections between disparate parts of the brain.
Chris
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Just a thought. I've forgotten most of what I learned in that class and though I've done some reading over the years, I'm not very knowledgable of brain physiology and development.
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John - The Eternal Pessimist.
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Hi, wow I see colors when I hear certain words or see certain things. When I was younger it was clearer. I got it when I saw people as well. It's hard to explain, you don't really see the color i.e. everything doesnt become tinted blue, it's just a really heavy impression that you just know is blue, red, green etc...
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That's exactly it ! That's synaesthesia.
Do certain words elicit the response, or any words ? Ditto faces ?
Chris
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx
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Hi, people and place names tend to do it. It's kind of funny, when I was smaller I thought it was a kind on insight into the person before I knew them. Always got along fine with blues and greens. I still kind of do it but nowadays it's more of an after-thought impression...it's kind of hard to explain and I feel a bit silly, havent told anyone since the first time I brought it up. I just assumed everyone was the same...much to my friends ammusement! :¬)
Some words do elicit a response although I'm not too sure anymore if those are just learnt recognition i.e too many tv ads with WAR written in red. Such as red/black/white for war etc..sex is orange..my first girlfriend was blue, faces definately do it.
I think if I do have synaesthesia it's great, as it means other people do to. Do we all see the same colors then? I told my girl about this thread, she's an OT so I always ask her loads of medical questions..she said she gets it too but I dont think it's like mine. I suspect everyone has synaestesia but to different levels of conciousness. Kind of like some people get the color impression like me but other people just have the impression that I sense with the color..good/bad/friendly/hostile/nice..etc
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Hi again, well I've been doing some reading and it seems there are loads of people like me, they even do tests on us! Can't thank you enough for giving it a name, I've searched before but not really had a target to look for. Theres lots of sites with more information, this is the first I read and it summarises quite well:
http://www.thecure.com/robertpages/synaesthesiapiece.html
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I have 20/40 vision in my right eye, 20/200 in my left eye. I can cover one eye(with or without glasses) and perceive a slight difference in hue looking at the same object.
Explanation... Lenses refract light. Light of different wavelengths(colors) propagate through a medium at different speeds based upon the medium's index of refraction. Since one of the corneas of my eye is thicker than the other colors are ever so slightly delayed by their wavelength and arrive at the retina at different times. Corrective lenses cannot fully correct this effect.
This same effect is what causes prismatic effect looking through a telescope or causes stars to twinkle. Colors appear to split into their component colors. Although I see no prism effect the perceived overall hue of the image is slightly affected.
My right eye does 90% of the work processing detail because from birth that eye had a sharper image and became my dominant eye. The left eye was fuzzy and therefore in most cases it's image is ignored.
One of the coolest days of my life was getting glasses and finding out that stars were pinpoints, not dandilion-like puffballs, and that you could actually "SEE" individual leaves on trees and see powerlines from over a mile.
But I notived the color difference very early on. BTW, at close(6" to 2') range, my left eye is capable of seeing much finer details and at lower light levels than my right. Comes in handy when trying to discern a tiny number on a dimly lit IC chip inside a PC from an extreme angle. Shame it only works up to 2'.
Stephen Firestone
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Welcome s_firestone - it's nice to hear from you.
Interesting differences. I wonder if your left eye is dominant at close range because it is nearsighted and thus gives better images up close while your right is better at distance.
The difference in hue is strange. I've never heard of that before, not that I'm in any position to hear much of those sort of things.
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John - The Eternal Pessimist.
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Hi, I didnt know I had a sight problem till I was around 10. When I got glasses the world seemed alot more vibrant and I had the same sort of thing. Clouds was my first wonder! Later I got contact lenses and yet again the difference was intense. The colors I see for things dont change though no matter which form of sight I use (none, glasses, contacts).
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Tann - I'm delighted that you turned up and gave such a clear description of synaesthesia, proving that I was not talking clap-trap above ! In answer to your comment about what people actually experience the answer is that it seems to be quite individual. Some people experience colours triggered by specific words or situations, others 'taste' shapes - in other words they experience a taste sensation when the see certain shapes. I think it must be a wonderful experience to have because it adds another dimension to the world as we experience it with our limited senses.
Stephen - I was about 6 when I first noticed that with one eye the fluorescent light in my classroom looked a creamier colour than with the other eye, which made it look stark white. I have since found quite a few people with this sort of mild disparity in colour perception between the 2 eyes. Initially I thought it might have something to do with retinal photoreceptors. I must admit I am intrigued by your suggested answer - which I have not heard before.
Chris
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx
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Maybe all these people who see auras are really just experiencing synaesthesia, but then, the color they see tells them something about the person. I guess there has to be some ESP involved in the brains choice of color for the individual.
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I don' think that it is a form of ESP. I thin that it is probably yhe fact thet certain colors like red automatically suggest evil where as blue may suggest calm or nice. Now i do not know that much about ESP so hat could be what i just described but i am not sre. I have a very small amout of synaesthesia. I had neverr realy though about it untill i looked at this site.
baby2michaelt[}:)]
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Whenever I see something with a faded-olive color, I tend to perceive it as grey where everyone perceive it as green. With some proper lighting I can see some green there, but not as dominant as the grey. However, everyone thinks otherwise.