The Coloured Door of Time

American Synesthesia Association

Colour terms from The Phrontistery

Blinded in an accident at 21, Zoltan Torey taught himself to visualise the world around him with such clarity that he was able to climb a ladder and replace his house's gutters.

"I use every miniscule clue I can to visualise you - your handshake, height, voice, movements, mood, character, remarks: I factor everything in." [...] What's more, he can control the colours. He likes moss green, sea blue and egg yellow. So if he meets a person he likes, does he dress them in these colours? Laughing, Torey responds: "Well, I don't see people naked! Yes I do clothe people I like in colours I like." And if he dislikes them, he'll probably put them in orange or purple."

- interviewed in the Sydney Morning Herald magazine Good Weekend, 28 June 2003

In Synaesthesia: The Strangest Thing, researcher Jon Harrison considers whether the synaesthesia caused by hallucinogens is the same as "idiopathic synaesthesia", the type you're born with. Probably not, he says: "recent PET studies of the effect of LSD suggest that the areas typically activated are not those that lit up in our PET experiment. This suggests that the neural substrates of auditory visual events as a result of drug use are not the same as the substrates of idiopathic synaesthesia. In fact, it is not clear why we should expect any similarity; the subjective accounts given by hallucinogen users and synaesthetes are, after all, quite markedly different". (pp 207-8)

It's an "unlikely concidence," says Ramachandran, that "the most common type of synaesthesia is number/color synaesthesia and the number area and color areas are right next to each other in the same part of the brain." Experiments showed that when numbers were shown to people with this form of synaesthesia, V4, the colour area, was activated, supporting the idea that there were connections between the two areas. The researchers also met a colour-blind synaesthete: "Because of a deficiency in his cone pigments (in the retina) he couldn't see he full range of colors in the world. Yet when looking at numbers he could see colors that he could never experience otherwise. He referred to them charmingly as 'Martian colours'." His eyes couldn't see those colours, but his brain could.

Another test showed that it wasn't the concept of the numbers which triggered the synaethesia, but the shape of the numbers: the subjects saw no colours when shown Roman numerals (V and VI) instead of Arabic numerals (5 and 6). (I see the colours associated with the letters!)

Colour processing is done in the brain in a series of steps, moving through different areas. Ramanchandran suggests that different kinds of synaesthesia might involve cross-wiring at different steps: for example, a synaesthete who associated colours with days of the week might have a cross-connection in the next step up from V4, the TPO junction, which handles the concept of sequences - a kind of "higher synaesthesia" which is "driven by numerical concept rather than visual appearance."

Ramanchandran suggests that the cross-wiring is the result of a faulty gene which hasn't done its job, in the forming brain, of pruning away excess connections. Faulty genes are normally weeded out by natural selection, so perhaps this one is actually doing something useful. Synaesthesia is much more common in "artists, poets, and novelists". Different kinds of synaesthesia result when the gene is expressed in different parts of the brain, but what it it's expressed throughout the brain? That would make "that person more prone to metaphor, the ability to link seemingly unrelated things." If "high level" concepts are processed in specific parts of the brain, like sequences are in the TPO junction, then "artistic people, with their excess connections, can make these associations much more fluidly and effortlessly". These are fascinating speculations. Ramachandran goes on to suggest that language may have arisen from these sorts of metaphorical connections.

I read this book last year and posted a bunch of stuff from it over in my main lj. I've been meaning to get back to some of the things it says about colour vision and synaesthesia.

Primates have "thirty areas in the back of our brains" involved in vision. The area called V4 is the one involved in colour vision. Ramachandran describes the effect of damage to V4: if it happens on both sides of the brain, the patient suffers from cortical achromatopsia, or cortical colour blindness; their eyes work fine, but their brains can't see colour.

In his chapter on art, Ramachandran talks about exaggerated figures in art, such as ultra-feminine Hindu statues, or Western political caricatures, in terms of "peak shift": the brain picks out the details that make a woman's body different from a man's, or Richard Nixon's face different from other men's; the more the artist exaggerates those details - big bust, big hips, or big nose - the more the brain notices them. "It looks comical, but it still looks even more like Nixon than the original Nixon." He goes on to apply this "peak shift" idea to colour in modern art by Van Gogh and Monet: "Hence the effectiveness of artificially heightened 'non-realistic' colors of their sunflowers or water lilies." So, because of the way the brain recognises things it sees, those flowers look more like flowers than actual flowers do. Blimey. I can't help being reminded of the Aztec idea that this world is just a "painted book", a poor imitation of the much more intense, but hidden, world of the spirit, in which flowers really would look more like flowers than actual flowers do.

More in a bit.

Via drhoz: the peacock spider.

The Munsell colour system makes me think of a map of the Planes from AD&D.

Incomplete and Complete Achromatopsia

HTML Color Names

Color Name & Hue is a colour identification tool for the colourblind.

Lesser Known Colour Vocabulary A-C, D-L, M-R, S-Z

"It was the floor which held Carson's gaze. The dull grey of the circular wall gave place here to a mosaic of varicoloured stone, in which blues and greens and purples predominated - indeed, there were none of the warmer colours. There must have been thousands of bits of coloured stone making up that pattern, for none was larger than a walnut. And the mosaic seemed to follow some definite pattern, unfamiliar to Carson; there were curves of purple and violet mingled with angled lines of green and blue, intertwining in fantastic arabesques. There were circles, triangles, a pentagram, and other, less familiar, figures. Most of the lines and figures radiated from a definite point: the centre of the chamber, where there was a circular disc of dead black stone perhaps two feet in diameter."
- Henry Kuttner, The Salem Horror

The world's heritage from space. Incredible colours - some of them must surely be artificial.

Pixelscapes

On the Laws of Japanese Painting

Fangblenny has coat of many colours: "The blue-striped fangblenny is the first fish found to be able to change its colour at will to mimic a variety of other fish. Its repertoire of colour changes includes olive, orange, and black and electric blue, and it appears to use colour vision to achieve its incognito exploits, new research shows."

Japanese colour terms (search for the word colour to find them)

Japanese traditional colour names

Japanese Color Guide

Hungarian has two words for red

Postage stamp colour names

sinople means both "red" and "green"

Australian Aboriginal artist Minnie Pwerle

Imaging of connectivity in the synaesthetic brain at the blog Neurophilosophy; more at the blog Madam Fathom.

'Can anyone hear that picture?', BBC News, 7 August 2008.

Colours for sale

More colours for sale

Fictional colours

The first vertebrates were tetrachromats and could see ultraviolet; many still can. Mammals, active at night, lost two of the four receptors - but later, primates evolved a new red receptor, giving us our three-colour vision.

The lens of the human eye blocks UV, but cataract patients who have had their lenses removed can see ultraviolet. Unlike animals which actively use UV (to identify mates, etc), humans don't have a dedicated UV receptor; but our blue receptors are also sensitive to violet and ultraviolet light.

Tetrachromacy: Some women may see 100 million colors, thanks to their genes

Language: Do Infants See Colors Differently?

Good heavens!: Researchers engineer mice to see the world as humans do

Beautiful: Sea Slug Gallery

Pop art: Ishihara Test for Color Blindness

Why I and O are dull for synaesthetes: the researcher found that "frequently used letters are most likely to evoke colours, while letters such as Q and X are less likely to do so. However, Eagleman spotted two frequently used letters that bucked this trend: I and O. He also noticed that the numbers 1 and 0 are often not coloured. Eagleman thinks this may be because these characters are made up from natural shapes that we learn to recognise before mastering the alphabet or learning to count."

I did wonder!

The 13 August 2005 issue of New Scientist reported that a remote Brazilian people, the Pirahã, have no words for colours - only for "light" and "dark". At first it was thought that they had a few colour words, such as "black", but these turned out to be descriptive phrases. A New Yorker article explains further:

"Everett also learned that the Pirahã have no fixed words for colors, and instead use descriptive phrases that change from one moment to the next. 'So if you show them a red cup, they're likely to say, "This looks like blood," ' Everett said. 'Or they could say, "This is like vrvcum" — a local berry that they use to extract a red dye.'"

A couple more ideas about colour from Aldous Huxley, this time from Heaven and Hell.

Huxley points out the association between colour and the spiritual world. Visions are characterised by "praeternatural light and colour". Heavenly realms are gorgeous landscapes filled with lush flowers and gems. Religious works of art, such as the stained glass window, evoke those colourful other worlds.

He goes on to suggest that the result of living in the drab, pre-industrial world was "a passionate, an almost desperate thirst for bright, pure colours" - people used to little more than "the duns and goose-turd greens of ragged clothing" would be transported by the displays of colour at the church or by the wealthy. The industrial world, by contrast, is saturated with colour: "We have seen too much pure, bright colour at Woolworth's to find it intrinsically transporting."

"Seigel put up a hotel-casino such as Las Vegas had never seen and called it the Flamingo... Everybody drove out on Route 91 just to gape... Such colors! All the new electrochemical pastels of the Florida littoral: tangerine, broiling magenta, livid pink, incarnadine, fuchsia demure, Congo ruby, methyl green, viridine, aquamarine, phenosafranine, incandescent orange, scarlet-fever purple, cyanic blue, tesselated bronze, hospital fruit-basket orange."

- Tom Wolfe, "Las Vegas (What?) Las Vegas (Can't Hear You! Too noisy) Las Vegas!!!" in The Kandy-Kolored Tangerine-Flake Streamline Baby.