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by Sharon Begley
Wall Street Journal,
Science Journal, June, 2002
Like many artists, Carol Steen paints what she sees. But judging by
the canvases that fill her loft in Manhattan's NoHo neighborhood,
her vision is, well, unusual.
This series of canvases, she explains one afternoon, depicts the
shapes and colors that appeared to her -- usually in her mind's eye
but sometimes suspended before her -- when she underwent acupuncture
treatments. In one, a luminous blue orb weeps emerald crescents.
Nearby hang paintings whose images she saw while listening to music:
flowing shapes in green, teal, gold and violent.
Ms. Steen is a synesthete, someone whose brain is "cross-activated"
so that one sensory experience (feeling or hearing, for instance)
triggers a wholly different one (seeing). The result is "a world in
multimedia," she says. "Synesthesia is a gift."
Brain researchers couldn't agree more. Because the condition
promises to shed light on puzzles ranging from the roots of
creativity to the origins of language, says V.S. Ramachandran of the
University of California, San Diego, "synesthesia is a gold mine for
neuroscience."
He estimates that as many as one person in 200 has synesthesia,
which can take as many forms as there are sensory pairings. Novelist
Vladimir Nabokov wrote that the sound of a long A in English "has
for me the tint of weathered wood, but a French A evokes polished
ebony." George Gershwin saw notes in color (ever wonder about
"Rhapsody in Blue"?), as did Franz Liszt, requesting of musicians,
"Gentleman, a little bluer if you please." For Ms. Steen, the radio
creates a kaleidoscope so riveting she prefers to turn off the music
when she parks her car. In a rare form, tastes have shapes. One
synesthete says a roast chicken in citrus sauce is done to a turn
when it is "pointed."
In its most common form, synesthesia makes you always see a
particular letter or digit in a particular color. To author Patricia
Lynne Duffy, P is invariably pale yellow, R is orange, 5 is purple.
"When I think of the alphabet, it's like a sloping scale of brightly
colored letters," says Ms. Duffy, whose book "Blue Cats and
Chartreuse Kittens" describes her world. One medical professor tells
psychologist Thomas Palmeri of Vanderbilt University that although
color letters slow down his reading, they help his memory: He
breezed through anatomy because the distinct colors of the terms
acted as mnemonics.
For decades neurologists figured people like the professor were
crazy or lying. Finally, though, brain imaging is establishing the
reality of synesthesia. In April, scientists at Goldsmiths College
in London reported on MRI scans of synesthetes who hear spoken words
in color. The brain area that processes color when you or I stare at
a cerulean sky or an emerald fairway is, in these synesthetes, also
activated by the spoken word.
Synesthesia probably strikes when the brain takes E.M. Forster's
maxim "only connect" to extremes. Everyone is born with extra
connections, or synapses. Most get pruned away in childhood. In
synesthetes, the extra synapses seem to remain, producing a rich web
of circuitry that connects the cortex's color processor to the
numeral area next door, or links touch regions to vision regions.
Since synesthesia runs in families, defective pruning might reflect
a genetic mutation.
While researchers have fun studying people who see Middle C, they're
after bigger game. "We hope that synesthesia can give us a window
into processes that occur in everyone's brain," says Edward Hubbard
of the University of California, San Diego.
Chief among them: creativity (which, after all, is seeing
connections that no one before you has) and metaphor (linking
seemingly unrelated concepts, as in "Juliet is the sun"). Scientists
suspect that crossed wires in the brain's angular gyrus, where
information from different senses converges, underlies synesthesia.
Not coincidentally, perhaps, when this structure is damaged, your
brain can't understand metaphor.
Synesthesia may even explain one of the great mysteries of science
-- how language originated. Try this: Draw one spiky shape and one
rounded, amoeba-like one. Pretend that, in a lost language, one is a
"kiki" and one a "shoosha." Which is which?
Almost everyone says the spiky shape is the kiki. "The spikes mimic
the sharp sound of "kiki," says Dr. Ramachandran. If appearances and
sounds are really linked in a non-arbitrary way in regular folks
just as they are in synesthetes, then early humans could have used
sound to represent objects and actions in a way the guy in the next
cave would understand. In that case synesthesia, far from being a
mere curiosity, offers a window onto the most human of human traits. |