Psychologists have used hypnosis to give people the ability to see numbers as colors.
The researchers, led by Roi Kadosh of University College, London and Luis Fuentes of Spain's University of Murcia, put three women and one man under hypnosis, then instructed them to perceive digits in color: one as red, two as yellow, three as green, and so on.
Upon waking, the subjects found it difficult to find numbers printed in black ink against correspondingly colored backgrounds. The numbers seemed to blend in - a telltale sign of synesthesia. When the hypnosis was removed, the ability vanished.
That form of synesthesia is naturally possessed by roughly one in 1,000 people, among them such historical luminaries as physicist Richard Feynman and writer Vladimir Nabokov, who saw "q as browner than k, while s is not the light blue of c, but a curious mixture of azure and mother-of-pearl."
Observations like these, long dismissed as extravagant fantasy, are now considered a window into the mysteries of perception. But despite a surge of scientific interest, synesthesia's mechanisms remain unknown.
Read Details on: http://blog.wired.com/wiredscience/2008/10/hypnosis-lets-r.html
