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Color comes calling,  rabbits that live on and on, warm weather thickens hair

Q: Synesthesia — a person hears a sound and "sees" the "sound color" also. What happens? How does the color appear? Over his whole view range? As an illusion? Does it blot out the rest of his view? —John, Albuquerque, New Mexico

Look at the top figure. Can you see the 2s? Look at the bottom figure. This is how the top figure appears to a synesthete who sees “green” 5s and “red” 2s even when they’re black numbers. She spots the 2s easily. [Vilayanur S. Ramachandran, University of California, San Diego]

A: One synesthete sees music that looks like "shards of glass" — a scintillation of jagged, colored triangles moving in her vision field. Another (novelist Vladimir Nabokov) saw "a tint of weathered wood" when he heard an English long A but saw "polished ebony" when he heard a French long A. Yet another synesthete sees blue when she plays C sharp on the piano. George Gershwin ("Rhapsody in Blue") saw notes in color.

Some people have a rare perception. Brain researcher, Vilayanur S. Ramachandran and his graduate assistant, Edward M. Hubbard, of the University of California, San Diego, found that one in 200 college students has synesthesia. Folks blessed with this spontaneous extra-sensory perception see colors projected into their personal space. Never at a distance. Never an illusion. It’s real to them. One college teacher hears music and watches golden balls fall, lines shoot upward, metallic waves float on a ‘screen’ six inches from her nose. Seeing and hearing mix.

The "symbol color" doesn’t blot out the "real" color, says Ramachandran . When seeing (say) a black number 5 printed on white — this is what a subject (who always sees ‘5s’ as red) perceives: The red color is not confined to the number itself but spreads like a halo around the number. But the color doesn’t block out the black. "I KNOW its black but SEE it as red."

Synesthetes’ brains are cross-triggered so one sense (hearing or tasting) fires another (seeing or feeling). The most common form results in seeing letters and numbers in colors. "I know it’s 2 because it’s white." Each letter or number has its own shade. These associations do not change over time.

Brain function may explain how such cross-activation mix-ups can happen, says Ramachandran and Hubbard. The eyes pass only sketchy information to the back of the brain for processing into attributes like color, motion, form, and depth. (Related: WonderQuest on the "Speed of Sight" http://www.usatoday.com/news/science/wonderquest/2003-01-17-wonderquest_x.htm). Then the back brain sends the information forward to another area (the fusiform gyrus) for more refinement, in the first of several processing stages.

However, this part of the brain almost touches the part that works with numbers. So, colors and number-shape processing can get mixed up here among synesthetes—probably due to a mutated gene. The condition runs in families. The "bad" gene inhibits pruning of brain connections. In childhood, the brain usually gets rid of extra connections; we’re all born with an excess. Synesthetes keep theirs and live an enriched life.

Creativity may have evolved through such brain cross talk. Poets, writers, and artists see life as metaphors. "Juliet is the sun." They link the unrelated and create insight. Much like synesthetes link senses. "Two is white." This may also explain why the seemingly useless synesthesia gene has survived among humans.

Going a step farther, perhaps synesthesia was the start of language as we linked sounds (sharp, like "kiki"; go ahead, pronounce it) with symbol shapes (pointy and sharp, "kiki"). Of course, kiki is not a word but words may have got started by similar associations.

Synesthete researcher Vilayanur Ramachandran asks WonderQuest readers, synesthetes, who read this article, please contact us at vramacha@ucsd.edu to relate your experience. "That would be a tremendous help!"

Further Surfing:

V.S. Ramachandran and Edward M. Hubbard, Scientific American: Hearing colors, tasting shapes

Richard E. Cytowic, Psyche, Synesthesia: a review of current knowledge

Rabbits that live on and on

Q: How old is the oldest living rabbit? —Elisa, Teaneck, New Jersey

Forty-five percent of house rabbits run loose inside. [Corel]

A: About a dozen years, but some live much longer. 

"My rabbit, Twigs... and is currently nearing sixteen," Tess Owen of Edmonton, Alberta, Canada emails. Twigs is blind and occasionally loses his balance, but "has an insatiable appetite and is always alert."

Three years ago, 453 rabbit owners responded to an Internet survey question: "How old is your oldest rabbit?" Most rabbits (53%) were under 2 years. However, 1% reported that their oldest rabbit was 10 years or older. A well cared for house rabbit that’s been spayed or neutered early in life will probably live for 8 to 13 years. Cottontail rabbits can live 8 to 10 years; European rabbits up to13 years.

Wild rabbits don’t fare so well (but can live up to 9 years). Only 50% of baby rabbits leave the nest. A recent study of 36 does showed they weaned 280 young and 252 disappeared during their first year — presumably died from natural causes. That’s 90%. Men, weasels, stoats, ermines, coyotes, bobcats, badgers, foxes, rats, owls, buzzards, ravens, crows, eagles, rattlesnakes, black-backed gulls, skunks, hawks, cats, and dogs gobble rabbits.

"Thump, thump, thump!" An old buck European rabbit crashes both his hind feet together into the ground to sound the alarm. All rabbits within earshot bolt for the burrows. A desert cottontail flags his white tail to warn others. Cottontails can both swim and climb trees to escape would-be eaters.

Warm weather thickens hair

Q: Approximately, how thick is a hair strand? — Vicky, Taipei, Taiwan

A hair shaft (138 X) [Paula Sicurello/University of California at Berkeley]

A: Fine hair is close to the resolution of the human eye — about as fine as we can see. Hair thickness varies from person to person, day to day, year to year. It’s anywhere between 1/1500 to 1/450 inches (17 to 181 microns). Hair color is the biggest factor. Flaxen hair is the finest (1/1500 to 1/500 inches, 17 to 51 microns) and black hair the coarsest (1/450 to 1/140 inches, 56 to 181 microns).

Warming weather can thicken hair.

(Answered Aug. 22, 2003)