WonderQuest:  On the web since 1997...      

Color comes calling, night must fall, rabbits that live on and on

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? —Carmela, 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

Q: Why does Earth have day and night? Do all planets have the same? —Charlene, Auckland, New Zealand

Sunset over Earth with Venus in shining above [NASA]

A: Earth’s spin about its axis causes night and day. Earth makes a complete revolution in 24 hours (a solar day). Imagine spinning a top in a darkened room. Shine a flashlight at the whirling top. A tiny bug crawling on the gyrating top experiences day and night as he passes into and out of the light—much like we do on rotating Earth.

All the planets in our solar system spin and therefore have night and day but the length of day varies greatly. Venus rotates through a "day", with respect to the Sun (not the stars), in 117 Earth solar days. A day on Mars is about the same as ours (24 hours and 40 minutes). Giant Jupiter whips through its day in only 9 hours and 57 minutes. The giant planets (Jupiter, Saturn, Uranus, and Neptune) contain most of the angular momentum of our solar system (even more than the Sun) and therefore spin faster than the inner planets. The Sun rotates slowly, only once monthly.

The Sun, Moon, and the planets formed from a huge spinning disk that formed from the collapse of a large gaseous dusty cloud. The original whirling disk gave its spin to the planets, which started them orbiting about the Sun and spinning on their axes. Using the Hubble Space Telescope, we have observed similar proto-planetary disks, for example, in the Orion nebula, says Robert Massey, astronomer at the Royal Observatory Greenwich. All objects that we know spin—the Sun, the Moon, stars, black holes, galaxies, planets inside and outside our solar system.

"There are circumstances in which planets wouldn’t have night and day although we don’t know of any yet," says Massey. A planet close to a star could have captured rotation (like our Moon relative to Earth). Then, it would always keep one face turned to its star sun. One hemisphere would be bathed in everlasting light and the other, permanent darkness.

Further Surfing:

WonderQuest: How Earth started orbiting the Sun

Royal Observatory Greenwich: Timekeeping by the Earth, Moon, and Sun

Griffith Observatory: Sunrise/sunset and the Sun’s path across the sky

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.

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.

(Answered Aug. 22, 2003)