http://dsc.discovery.com/news/afp/20041018/seecolor.html
Oct. 21, 2004 — People who believe they have the psychic power to see colored auras around others may have an unusual form of synaesthesia, suggests a U.K. researcher.
Dr. Jamie Ward from University College London reports a case of "emotion-color" synaesthesia in the October issue of the journal Cognitive Neuropsychology.
"A popular notion is that some people have a magical ability to detect the hidden emotions of others by seeing a colorful 'aura' or energy field that they give off," said Ward. "Our study suggests a different interpretation.
"These colors do not reflect hidden energies being given off by other people, rather they are created entirely in the brain of the beholder."
In people with synaesthesia, or synaesthetes, stimulating one sense produces a response in one or more others. For example, sounds may trigger colors or smells, and tastes may trigger shapes.
Synaesthesia affects one in 2,000 people and runs in families. Researchers know little about its neural basis but a number have suggested cross-wiring or cross-activation of areas in the brain causes it.
In his paper, Ward described the case of a 19-year-old woman, named GW, who experienced colored "auras" projecting out from people she knew.
She also experienced vivid color across her whole field of vision in response to highly emotive words, such as fear or hate. This also applied to the names of people she knew. For example, the name James triggered pink, Thomas black and Hannah blue.
Ward also found that negative words or names triggered brown, grey and black whereas positive words emotions triggered pink, orange, yellow and green.
Ward cited five published case descriptions from the 20th century showing emotion triggering color. He suggested that color-emotion synaesthesia may be due to cross-wiring between two parts of the brain. One part, the retrosplenial cortex, has been implicated in emotion and memory.
"This region is known to respond both to personally familiar people relative to unfamiliar people ... and to emotional words relative to neutral words ... and has previous been implicated in synaesthesia," Ward said.
Ward said this region was in the middle, back part of the brain, which made it an attractive candidate for cross-wiring with nearby visual regions.
Australian researcher, Anina Rich of the University of Melbourne, is completing her PhD on synaesthesia.
She welcomed the study, which she said was thorough, and was interested in the suggestion that learning, or getting to know someone, could influence synaesthesia.
Rich has previously found that in a group of 150 synaesthetes, people had experienced colors when seeing, hearing or thinking about a particular letter, number or word, including names, or days of the week or month.
She said that Ward's findings seemed to be a specific form of this, where the words that stimulate color were restricted to people with an emotional connection.
But Rich was equivocal as to whether the research helped provide a scientific explanation for auras.
"It's interesting. I guess it's possible," she said. "I generally think of synaesthesia as different because there is scientific evidence that it exists."
She said people who saw colors associated with particular names tended to emphasize this was more about their own experience, rather than about the other person.
"One of the nice things about synaesthesia is that it reminds you that your perception is entirely subjective," she said. "It's GWs perception of other people that is coloring her experience with them."
Rich said that her most recent unpublished research had found that women were six times more likely to have synaesthesia than men.
