WASHINGTON -- For one middle-aged man, "two" looks blue, but "2" is orange. And while "3" appears pink, "5" is green.
The man has synesthesia -- a phenomenon in which printed words and numbers burst with color, flavors take on shapes and the spoken language turns into a mental rainbow.
For some people with synesthesia, say researchers, a newspaper is never black and white -- it's red, orange, blue, beige, pink and green all over.
"This is an alternate perception," said Thomas J. Palmeri, a Vanderbilt University psychologist and the first author of a study reporting on the tests given to one man. "He is normal -- a highly successful, intelligent man and he suffers no problems from this unique wiring of the brain."
The study, appearing today in the Proceedings of the National Academy of Sciences, explores multi-chromatic world of a man identified only as W.O. The man, a university professor of medicine, did not respond to requests for a direct interview.
A rich symphony of senses
Palmeri said researchers are starting to realize that W.O. is just one of a large number of people with synesthesia, many of whom take joy in this rich symphony of sensations.
"They often experience a great deal of pleasure from this altered perception," said Edward M. Hubbard, a synesthesia researcher at the University of California, San Diego.
For W.O., his synesthesia helped make learning the complex words of science easy -- when the colors weren't distracting him from study, Palmeri said.
"He sees a palette of different colors when he reads and sometimes he is more interested in how pretty the page looks than what the words say," he said.
In the Proceedings study, Palmeri, Randolph Blake and Vanderbilt researchers put W.O. through a series of tests.
Palmeri said that W.O. sees all printed words in colors, sometimes letter-by-letter and sometimes syllable-by-syllable. Short words have a single color while long words may have many.
When W.O. was given a list of 100 words printed in black and white, he said each one had a specific color. When the list was presented a second time, weeks later, W.O. gave most words the same color, missing only some that were either beige or off-white.
"These associations are highly reliable," said Blake. "W.O. says that the colors have stayed the same all his life and our observations lend credence to the claim."
In W.O.'s view, each numeral, except for zero and one, has a color even if printed in black and white.
When the researchers presented an image of the number 5 made up of much smaller number 2s, W.O. saw the whole image as a five and it appeared green. However, when he looked at the small 2s that made up the image, each of those numerals were orange.
When the numbers were written out -- such as two -- they assumed another color.
And the hues prompted when W.O. hears words are generally the same as those he sees when the words are printed, Palmeri said.
Hubbard said the experiments with W.O. match some performed in his lab that show synesthesians see colors when others see only black and white.
Hard to understand
Just how W.O. perceives this color is difficult to understand, the researchers said.
"He tries to describe it to me and I still can't appreciate it. It's like trying to describe colors to a person who can't see them," said Palmeri. "How could you describe color to a blind person? You really can't."
Some researchers believe that about one in every 25,000 people has synesthesia, Palmeri said. Some studies suggest it may be much more common -- closer to about one in every 200 people, Hubbard said.
One theory holds that the perception is inherited. W.O.'s mother, maternal grandfather and great uncle also experience synesthesia, but none of his siblings or children do.
Hubbard said that so little is known about synesthesia because many people won't admit it. Others, however, are surprised to learn that they are unusual.
Connect with the Southeast Missourian Newsroom:
For corrections to this story or other insights for the editor, click here. To submit a letter to the editor, click here. To learn about the Southeast Missourian’s AI Policy, click here.