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Sky-blue-pink. A colour never before seen? - Comments

jon_the_d's Avatar Comment 1 by jon_the_d

I've been considering these points recently too, particularly echo-locating and smelling in "colour", where the animal has enough information coming in to that particular sense for the brain to construct an 'image' of their surroundings using that sense, and would most likely use 'colours' to 'display' that image to the brain. I analogized it with false colour photos we see of x-ray emissions or heat etc. Particularly in animals whose sight is of secondary importance, so for example perhaps bats, moles, and some deep sea fish.

Although if you consider hearing, where certain animals are able to pinpoint the origin of the sound, and have a full 360 representation of the aural surroundings, I think we can assume through our own experience that the sounds are identified by their own qualities (amplitude, frequency, wavelength etc.) and it would be hard to reason that blind animals would have evolved an actual 'image' of their surroundings based on the incoming sounds? Perhaps the timbre of a sound is the aural equivalent of colour, and comparing how we ourselves see to how we hear, is the closest we can get to realizing how senses unknown to us may be represented in the brain.

It seems brains have evolved to treat the different senses quite differently, with sight being prioritized as a way of representing our surroundings. Echo-location would be a near approximation and I could see it evolving to actually provide an 'image' to the brain, one which could easily be evolved from greyscale (distance) to colour (distance + texture).

One group of people that it would be interesting to talk to/research, are the blind people who can echo-locate by clicking. Especially one who was born sighted. They may be able to provide some insight into how the brain 'sees' by their clicks.

As for the colour blind people, short of brain surgery, perhaps they will develop a cure of some kind, or even an electronic eye with full colour capability, triggering precisely those unused 'labels' you speak of. Imagine then, if they can then use these techniques to give those born blind full colour vision!! That would be an incredible experience! Not just new colours (amazing enough) but a whole new sense!

Perhaps stem cell research will recreate a functioning eye (didn't they just do a retina? [EDIT: yes they did...kinda.. http://www.upi.com/Science_News/2010/06/01/Early-stage-retina-created-from-stem-cells/UPI-89191275416481/)

If they ever do this, they have to get the first reactions on camera!!!

Updated: Sat, 12 Jun 2010 11:15:22 UTC | #479567

at3p's Avatar Comment 2 by at3p

I don't think it could be the awe would be more powerful than a child walking into a room which is painted in colors s/he didn't know before. But quantity of color is also vital. If you just pick up some small spots of new color, it would just be a peculiar feeling. It's difficult to think of a new color anyway, since the entire spectrum has been mapped, but I would love to see infrared and maybe UV light with my own brain...

Maybe normal people can get the awesome feeling of experiencing new colors after spending a few weeks in a dark bunker, (this wouldn't work in a during a gray autumn season in urban areas).

Sat, 12 Jun 2010 11:20:42 UTC | #479569

Numberwang's Avatar Comment 3 by Numberwang

You might find this interesting.

http://www.youtube.com/watch?v=ZDD7Ohs5tAk

The baby in the film must be going trough the analogous experience.

Sat, 12 Jun 2010 12:12:29 UTC | #479578

deziner's Avatar Comment 4 by deziner

Maybe you should ask a person who was born deaf but gained the sense of hearing on receiving a cochlear implant. Many of these deaf people (who receive the implants as children) have never heard anything before, so would apparently have no concept of what things sound like. But stick an implant in their ear and all of sudden a whole new sensation is opened up to them.

No doubt hearing the human voice for the first time would be like seeing a brand new colour.

[edit] Beaten to it

You might find this interesting.

Updated: Sat, 12 Jun 2010 12:15:48 UTC | #479579

zirconPhil's Avatar Comment 5 by zirconPhil

Never had a dream where you remember colours, just have memories of dreamed events the next day. I would doubt, however, the possibility of seeing new colours in dreams since dreams are based on things you already know and go from there with imagination.

BTW running a red light is NOT an excuse if the red-yellow-green lights are in specific positions (e.g. here, red is on top, yellow middle, green lower).

I can usually see the red, but occasionally, with certain lighting conditions, the red looks like a yellow to me. That's when I look at position of the lights to make sure I know what to do.

In my experience, I know all the colours, it is just when they are similar in hues that I have trouble - e.g. yellow and pale lime green. The only way for me to recognize if a sample colour was one or the other would be to compare it to a sample of yellow. That way I can notice the minute hue differences and tell which is which, usually (but not always) without much trouble. Many people have it worse though.

Sat, 12 Jun 2010 12:21:01 UTC | #479580

Dan0314's Avatar Comment 6 by Dan0314

While reading your article it struck me as very familiar. My father was deaf, losing most of his hearing due to some illness when he was about three. We talked with sign language. I would spend hours growing up and my adult life talking with him about the world and news because he was totally cut off, but I knew his brain worked just as everyone else did because he reasoned like everyone else but wasn't tuned in to general knowledge by hearing as we all are. I knew it was just his ear that didn't work, as your article describes the colour blind eye. His vision awareness I believe took over the hearing portion of his capabilities as he was vigilant as an eagle. I asked him if he would ever get a hearing implant to hear what we hear but he wanted nothing of that, thinking he would be shocked and too surprised. He was by far more visually aware than I was with my hearing to rely on. And his ability to express detailed language and ideas visually amazed me. The sign language was faster to convey ideas than talking and produced equivalent meanings as our sound talking language. I always felt his brain compensated, it was so sharp.

Updated: Sat, 12 Jun 2010 12:31:39 UTC | #479581

mariusthart's Avatar Comment 7 by mariusthart

I've always found the concept of qualia rather far fetched. It seems like it means people are born with knowledge instead of acquiring it. I think it's unlikely the brain works that way. The development of vision in children suggests to me there is no such things as qualia, instead, the labels for colour are learned and therefore not exactly equal for everybody. But, since it is constrained in both the input side, the architecture in which it has to be implemented and the form of the output that can be used by other brain areas it will still be highly similar. (I'de even say that the meaning we assign to colours will also be highly similar since we live in the same universe, on the same planet in human cultures.) A lot of recent colour experience research actually points in that direction.

So my guess is that colourblind people do not have a label for something they've never encountered. Just like all of us aren't born with platonic ideas for objects that haven't been invented yet.

Updated: Sat, 12 Jun 2010 12:34:24 UTC | #479584

nancynancy's Avatar Comment 8 by nancynancy

Thinking out loud, some colors like basic brown, tan, blue and green are often found in nature. Other colors like hot pink, purple and dayglo orange are rarely found in nature (unless you're scuba diving or looking at a flower or a rainbow). Before modern paints, dyes and color photography were invented people were not exposed to the incredible range of highly saturated colors we experience today, and some people experienced very few colors (mostly muddy earth tones) throughout their lives. The world of vibrant color that we take for granted today didn't always exist.

Updated: Sat, 12 Jun 2010 12:45:11 UTC | #479587

Art Vandelay's Avatar Comment 9 by Art Vandelay

I have even gone so far as to speculate that bats might hear in colour.

Some people associate sounds with colour: many musicians and composers for example, associate different keys with different colours. It's an aspect of synaesthesia, that condition where sensory experiences overlap. But interestingly, if you compare composers' lists of colours/keys, they don't usually match (so your red isn't the same as my red!)

I'm wondering if the condition occurs because of the doubling up of neurological pathways.

Sat, 12 Jun 2010 12:51:54 UTC | #479588

Nastika's Avatar Comment 10 by Nastika

There is a recent paper in Nature: Mancuso et al. 2009: Gene therapy for red–green colour blindness in adult primates (doi:10.1038/nature08401 and http://www.nature.com/nature/journal/v461/n7265/full/nature08401.html) that sheds light (ahem) on the question:

It describes how an L-opsin carrying recombinant adeno-associated virus was injected into the retinas of adult squirrel monkeys with red-green colour blindness. These dichromatic monkeys could only make out blue and yellow hues whereas their trichromatic counterparts could make out blue, yellow, red and green.

The dichromatic (colour blind) monkeys carried out a test before treatment that measured who well they could see colour hues. As expected they were unable to distinguish between blue-green and red-violet hues.

Five months after treatment, the dichromatic monkeys were found to have trichromatic vision after carrying out the same test.

The authors conclude that there was no rewiring of neural circuitry in restoring trichromatic vision based upon the fact that the new colour vision appeared at the same time as high levels of transgene expression. They were clearly unable to determine whether the monkeys experience new internal sensations of red and green but they go on to mention that evolution acts on behaviour not on internalised experiences so that their therapy repeated what happened during the evolution of trichromacy in primates.

Sat, 12 Jun 2010 12:55:22 UTC | #479589

mtmoriah's Avatar Comment 11 by mtmoriah

Richard, I don't know if you have ever read a short interesting story written by Luis Lowry. It is titled, The Giver. In it, a young boy, Jonas begins to see the color red for the first time, but only once in a while. The rest of his community is actually color blind through genetic manipulation and controlled breeding over many years. The author tries and succeeds (in my opinion) to describe wht it would be like to see a color for the first time, you might want to spend an afternoon reading the book, it is quite original and thoughtful.

Sat, 12 Jun 2010 13:10:06 UTC | #479592

bendigeidfran's Avatar Comment 12 by bendigeidfran

Yes when the top one's shining you have to stop.

Sat, 12 Jun 2010 14:16:15 UTC | #479607

TrumpetPower!'s Avatar Comment 13 by TrumpetPower!

Richard, I don’t know if you’re aware of it or not, but some women are tetrachromats, with additional sensitivity between the red and green portions of the spectrum.

And, as I have no doubt you’re aware, we only see an incredibly narrow band of the spectrum — all of about an octave, centered around the peak output of the sun (fancy that). Other animals can see farther into the infrared and ultraviolet than we can. The research that Nastika referred to points to the possibility of engineering such photoreceptors into a human. Or, even more intriguing, the possibility of engineering photoreceptors that don’t yet exist. Would the brain know what to do with the information? I rather suspect it would.

As an amateur photographer who’s spent some time trying to make accurate reproductions of artwork, I’ve become fascinated with color science. I’ve measured many, many color swatches with a spectrophotometer and plotted their spectral characteristics. It’s changed the way I look at color. Similar to how somebody with perfect pitch can hear a complex chord and spell out all the notes that comprise it, I’m pretty sure that somebody with sufficient training could look at a color and draw a reasonably-accurate spectrograph of it. It would take a lot of practice, much more than the time I’ve put into it, myself. But I’ll bet you a beer that it could be done.

Going back to my earlier point…if I were to design the eye, I’d have much more than just three (four if you include rods) kinds of photoreceptors. The three we have overlap each other somewhat in sensitivity, which is a good thing. I’d have a dozen (or more) overlapping photoreceptors, covering the spectrum from the far infrared to the far ultraviolet. (Much beyond that, and there both isn’t much that’s bright enough to observe and the optics get tricky with the size of the eye.) You’d see flowers the way a bee does. You’d see where all the heat is leaking into and out of your house where the insulation isn’t up to par. You also wouldn’t be satisfied with color TV or magazine prints any more, as they’d look cartoonish due to lack of color. At the same time, subtle variations in color would be easy to see. And so much more….

Cheers,

b&

Sat, 12 Jun 2010 15:16:56 UTC | #479618

johnb24's Avatar Comment 14 by johnb24

We will never be in a position to determine if our sensation of (say) red is the same as that of another individual (Richard D, above).

All of our knowledge/experience of the empirical world/world of experience resides in our own brains (does it not? I'm really asking). As well as colour (discussed above) does not a similar question arise for much, if not all, else?

Do we in fact live in a shared world? And before screaming an obvious "yes", think about it a bit.

Wittgenstein said that consciousness exists only in the singular.

John

PS The philosopher Bryan Magee has carried out several interviews with unsighted (blind) people and has published some ideas.

Updated: Sat, 12 Jun 2010 15:41:30 UTC | #479627

Jeremy Collins's Avatar Comment 15 by Jeremy Collins

It would probably not be very much different from discovering a new taste or smell. It is an intriguing sensation when it happens. My most recent example was smelling a bottle of alcohol in China which had a dead snake inside. I was surprised that I immediately recognised the smell, feeling an innate concept SNAKE suddenly activated, despite never having it smelt it before.

It is also quite clear in the case of taste that there must be subjective variation with humans - my 'milk' is different from someone who dislikes 'milk'. (Or are the qualia the same and just our reactions different? Is there a difference?)

Sat, 12 Jun 2010 15:54:25 UTC | #479633

ARL's Avatar Comment 16 by ARL

I sort of doubt that unexperienced subjective colour labels reside in some nativist fashion in the brains of the colour-blind. After all, red-green colour blindness doesn’t literally mean not seeing red or green, or that you confuse the two, but that you have a two-dimensional colour-space rather than a three dimensional one. “Red” isn’t coded for by the firing of the long-wave cone, but by the distribution of activations across all cones (after the brain has taken account of relative brightness of surfaces at V4 to filter out constant illuminance). The long-wave cone is just maximally active when red is seen. So the colour-blind just have a flatter colour experience overall, and find it more difficult to discriminate colours because there are only two axes of comparison.

Remember that, from rather cruel experiments with cats, covering up a perfectly good eye from birth will cause neuroplastic changes such that the axons which would have referred to receptive fields at the covered-up retina are diverted for use at the uncovered retina. Once this has occurred, it is irreversible. Uncover the eye, and it will never see. Use it or lose it.

Also remember that newborns have a relatively underdeveloped colour experience, seemingly only able to discriminate colours close to the peak sensitivites of the three cones. More acute discrimination develops as the nervous systems develops. Natural selection can rely on certain inevitable experiences to drive certain aspects of neuro-development, only building in what it needs to.

Now, I would suggest that colour qualia are generated by the brain by relative comparison. It needs to discriminate and use information from opponent cells where retinal axons synapse, and there is the requirement that it make available to ‘consciousness’ the subjective sense that these opponent labels are maximally contrastive, and sufficiently different from one another (R-G, B-Y, Dark-Light). The particular sensitivity ranges of human photoreceptors would have been selected for by ancestral discriminatory demands, but I see no reason why selection would need to “build” in the labels for them. I would further suggest that colour develops in a (guided) neuroplastic process that expects certain inputs to be there. When there is partial poverty of input from the photoreceptors, the discrimination demands placed on it are lessened, and so the brain never needs to ‘make’ the colour.

Reflect on the fact that colour-blind people have a flatter colour experience, not because they can’t see a particular colour, but because they have reduced discrimination because they can’t ‘triangulate’ and thereby precisify. If all the colour labels were already in the brain, we might suppose that they didn’t have a flatter colour experience, for why should they? They still have M and L cones, but their sensitivity curves are too close for relative comparison. Why wouldn’t colours that were hard to discriminate switch between two distinct colour labels like Necker Cubes? If the labels were already there, then the only problem for the colour-blind brain would be ambiguity – that there are two equally possible reflectance profiles for this one surface. When this happens for 3D cubes, where there are no helpful contextual cues, the visual system happily flips between both models.

I suggest that this is what would happen in the colour blind if all the trichromatic spectrum labels were available to thei brain. Instead, certain colours are as indistinguishable to them as metamers are to trichromats (e.g. a sensation of “yellow” can be caused by equal amounts of ‘red’ and ‘green’, or by ‘yellow’ light, and we can’t tell the difference). If we had an fourth cone which peaked at ‘yellow’, we COULD differentiate these two ‘yellows,’ and our brains would have needed to develop a fourth axis to our subjective colour-space. But the R-G colour blind only have two points of comparison, and only need two axes. You would have to rewire complex systems of connections throughout the visual pathways to give them a third. Or perhaps, if you could fix the problem at the retina, the brain’s plasticity would happily do the job for you, as it compensates under so many other pressures. But I don’t think the colour label would be ready and waiting for the job.

Just a (long) thought.

-Adam.

Sat, 12 Jun 2010 16:32:17 UTC | #479646

phil rimmer's Avatar Comment 17 by phil rimmer

I have a sneaking suspicion that all the available colour experiences are utilised in the brain. If one of the three stimulating sensors is deficient then the available sensations are "distorted" down to fully occupy the limited (flattened) colour space. Acquiring a new sensor input through gene therapy or some such, would probably result in some things of the newly sensed colour initially appearing brighter versions of an existing colour, before eventually the colour space became "(re)-inflated" with increased gradations becoming more common and more objects shifting into different colours.

So, the sensations already exist but your brain needs a bit of time to learn how to best use the extra information.

Sat, 12 Jun 2010 16:52:01 UTC | #479652

TobySaunders's Avatar Comment 18 by TobySaunders

Like alcohol, LSD can do brain damage (I'm ok with the legality of both regarding adult use in conjunction with drug-education, but that's a side issue).

On that issue of seeing other colours & the like, salvia divinorum is legal in the UK & most of the US: it sort of takes apart one's consciousness and puts the pieces before you in a sort of abstract & visceral way with profoundly vivid hallucinations/delusions.

It doesn't have that brain-damage-potential/toxicity-level LSD does, -anyone interested in temporarily taking apart their respective consciousness and possibly seeing a new colour could try that (I'm just sharing the knowledge)... it can have a therapeutic effect at best, although money really should be used to save lives. Salvia divinorum could perhaps have research potential for understanding consciousness, including colour processing... somehow I suppose!

I used it and believed reality was coming to a finish because I had 'figured out the answer'... all I 'had to do' to sort of 'finish up reality and see what is behind the scenes' as it were, was go outside and save a little boy in my drive-way. I went out, the boy wasn't there and I realised how vulnerable the brain is to delusion: I found it insightful, at least!

Sat, 12 Jun 2010 16:53:44 UTC | #479653

Thanny's Avatar Comment 19 by Thanny

I rather think that all of us with the proper opsins perceive red or green or blue in the same way.

For all our variety, which is substantial, study after study reveals just how identical we are when it comes to the basics of perception and behavior.

I expect the subjective experience of color (and sound, for that matter) to fall squarely in that category.

With the possible exception of those rare women who possess an extra opsin. I don't expect they experience any new colors. What I suspect is that the extra opsin (which may be a slight variation on red, or a slight variation on green) would be wired up as its normal counterpart. This may very well skew the colors of objects compared with the rest of us. But I'm more inclined to think they still experience the same subjective colors, and instead would describe objects as being of a different color, when pressed for extreme detail. Unfortunately, I have seen no empirical data on these points, so I'm speculating.

Sat, 12 Jun 2010 16:55:48 UTC | #479654

jim.spice's Avatar Comment 20 by jim.spice

My ten-year-old daughter within the past month has approached me with both "does everyone see red as red, or is my red their blue?" and "what's on the other side of the last star?" We must be doing something right.

On a somewhat related note, I have always been jealous of those who can visualize beyond the standard 3+time dimensions. In graphing multi-variate equations, I've fallen back to imbuing 5th-and-beyond variables with non-traditional properties. That is, not only is a data point plotted on x,y,z and T axes, but is assigned gray-scale hue, rated from smooth to fuzzy, is loud or quiet, etc. I'd never make the attempt to explain these to others, but they have served as a useful little mind tool to me.

Updated: Sat, 12 Jun 2010 18:12:04 UTC | #479673

smithichie's Avatar Comment 21 by smithichie

I wonder if the right spot exists within the brain that under stimulation would allow a human to see ultraviolet? All humans, along with the majority of the rest of mammals can't see ultraviolet, but we know it's a more colorful world to a whole host of other critters who can see ultraviolet. Seeing many flowers under UV light can be like seeing that flower for the first time. Where we may see a single tone can exist complex patterns completely invisible to us.

Sat, 12 Jun 2010 18:10:21 UTC | #479675

CanuckRob's Avatar Comment 22 by CanuckRob

Perhaps the work mentioned by V.S. Ramachandran regarding the "martian" colurs reported by a colour blind man with synaesthesia. He "sees" colours when he looks at a number and some of thse colours are ones he does not see otherwise. I don't know if anyone has tried to determine if one on his "martian" colours is consistent with the description of any "real" colour. This seems to imply that there exists a brain label for colour that is usually activated by signals from the appropriate opsin but that can be activated by a "misfiring" in a synaesthetes brain.

http://psy.ucsd.edu/chip/pdf/SciAm_2003.pdf

The above link is to a Scientific American article.

Sat, 12 Jun 2010 18:16:56 UTC | #479679

justaperson's Avatar Comment 23 by justaperson

I'm skeptical of synchronicity, but it happens that I was just thinking about this the other day. Someone was telling me of a friend who had had cataract surgery and as a result of some glitch was now able to see ultra-violet. I remain skeptical of the claim, but it made me wonder, 'suppose we could see ultra-violet, what would it look like? It's absolutely impossible to say, simply because it's impossible to describe 'red' without calling it red.

As a musician, I might make an analogy between the color-blind person and a person who can hear all the tones in the diatonic scale except one. If that person were a composer, it would seem natural to her to write music without, say, the tonic of the scale. To the rest of us such music would sound vague, inconclusive (literally!) and incomplete. To turn the analogy back on itself, suppose the case of a color-blind painter. He wouldn't be able to tell the difference between a set of colors with reds and one without. To the non-color-blind seeing his work, the paintings would appear drab and limited, taken as a body of work. It makes me wonder if color-blind people are less interested in art than others.

Another thing worth contemplating is the idea that as many of us age and our senses of sight and hearing become compromised, the brain steps in and in effect tells us that we are doing about as well as we always have (up to a point, and then we get so bad the brain can't keep up). For example, until I had cataract surgery on one eye, I thought I was still seeing colors OK until I compared my 'new' eye with the 'old.' The color vision of the latter looks positively dingy compared to the former! But I hadn't noticed the change because it happened over time. Similarly, we don't notice our increasing hearing loss (if we have it) so much when we hear familiar speech and music, because our brain fills in that which we actually don't hear and makes us think we're hearing things we're not.

Sat, 12 Jun 2010 18:22:45 UTC | #479683

bendigeidfran's Avatar Comment 24 by bendigeidfran

We don't see the dividing line between one colour and the next, we impose it. Most people here would divide the colour space into eight categories, the Berinmo of Papua New Guinea has only five colour names for the same range. But the difference between the two cultures is not that the Berinmo just have a relatively crude way of describing colour differences, rather they perceive fewer distinctions.

See Jules Davidoff 'Language and Perceptual Categorisation', Trends in Cognitive Sciences 5:9 (September 2001), 383-387.

Sat, 12 Jun 2010 18:32:29 UTC | #479688

bendigeidfran's Avatar Comment 25 by bendigeidfran

See also 'What's it like to be a Dawkins?' by Nagel.

Sat, 12 Jun 2010 18:34:50 UTC | #479689

huzonfurst's Avatar Comment 26 by huzonfurst

This is something that has always interested me. Humans perceive just under one octave of light but several octaves of sound. When we hear tones an octave apart we can easily recognize their similarities as well as their differences: a high C is different than a low C but they are both still a C!

It seems reasonable to suppose that the same thing would happen with colors if we could ever find (or design) a human sensitive to more than one octave of light. Even now there are qualities of both redness and blueness in the highest-frequency color we can see, namely violet, on the verge of the next higher octave.

I have also experienced synaesthesia myself, thanks to being in college in the 1960s and enjoying some incredible LSD trips. Hearing colors and seeing sounds is a common effect under the influence of psychedelic substances, and I value the experience. There is nothing like a live demonstration of how flexible our brains really are to keep one humble about what we think "reality" is!

Sat, 12 Jun 2010 18:35:43 UTC | #479692

God fearing Atheist's Avatar Comment 27 by God fearing Atheist

Comment 16 by ARL

Remember that, from rather cruel experiments with cats, covering up a perfectly good eye from birth will cause neuroplastic changes such that the axons which would have referred to receptive fields at the covered-up retina are diverted for use at the uncovered retina. Once this has occurred, it is irreversible. Uncover the eye, and it will never see. Use it or lose it.

Dear Richard,

ARL is correct. I suggest you read David Hubel's book. It's downloadable.

Having read the book, my guess is that a person born colour blind would not have the neural machinery for colour vision, but it would be a fascinating experiment.

Currently electrode arrays are being developed that can be implanted into the brain and connected to a camera system. I think the current limitations are the number of electrodes (64*64?) and the lack of a permanent connection. The electrodes are neurophobic rather neurophylic.

I would be fascinated to see what would happen if one of these was planted into V1 of a colour blind person, and the array connected to a trichromatic camera. Would adult neuro-plasticity learn to see colour, or would it be too late?

On the more general question of qualia, and inter-species qualia, I don't think philosophical musings help. I take the pragmatic approach of considering computer and robotic systems.

From the computational viewpoint all animals need algorithms (that work on neural hardware) to make sense of noisy sensory data. So a bat has to extract the echo-features that are common to moths, and an ape has to extract the colour-features that are common to ripe fruit. Given the common mammalian heritage, I am sure the neural circuitry is the same.

If you have a few months to devote to it, I recommend the books of Prof. Edmund T. Rolls for an undergrad introduction to computational neuroscience. I also found Prof. Shimon Edelman's "Representaion and Recognition in Vision" useful. I am sure Dan Dennett is familiar with both of these authors, and can steer you.

Sat, 12 Jun 2010 18:49:14 UTC | #479696

bendigeidfran's Avatar Comment 28 by bendigeidfran

Comment 26 by huzonfurst

Apart from the ones that only perceive five.

Sat, 12 Jun 2010 18:50:33 UTC | #479697

seals's Avatar Comment 29 by seals

While at school, I heard someone being disbelieved by a teacher for saying they dream in colour - "don't be silly, no one dreams in technicolour" - so it appears that, rather than seeing the normal range of colour, that teacher must have dreamed in black and white! Was it the effect of black and white films and TV, which were more prevalent then (the early 1970s), or do some people still dream in black and white?

Re comment 16 - I used to think that was what colourblindness was - ambiguity of colours, which would still be as vivid as in a non colourblind person, but the colours in question eg. red and green could be changed into one another by willing the alternative, like a necker cube, and there was no way to know which was the correct version. I'm not colourblind to my knowledge and have passed any colourblindness tests I come across. However I once owned a pair of horizontally striped blue and green socks, and by concentrating I could see the green as blue and the blue as green. Whether the stripe pattern had something to do with it, I don't know.

Some colours in dreams are particularly memorable, not always the brightest ones, but they leave a vivid impression that jumps out when you encounter that colour in a waking experience. I have seen very brilliant white light which under normal circumstances I couldn't look at because it would dazzle.

Sat, 12 Jun 2010 19:05:31 UTC | #479704

Puck Rickenbacker's Avatar Comment 30 by Puck Rickenbacker

In the early 1970's several of us knew a young man who had been blind from birth, and one evening we saw him sitting at the base of a shopping center sign. When we stopped to say Hi to him, he told one of the guys with us that he was doing LSD for the first time, and he thought maybe he understood what colors were, now.

We left in tears it was so profound.

Sat, 12 Jun 2010 19:34:50 UTC | #479708