It Sounds Blue! Kandinsky and the Brain

LETTERS, words, numbers, sounds, touch, pain and smell all trigger flashes of colour in Carol Steen's mind. The New York-based artist first discovered she could paint her synaesthetic visions after a visit to her acupuncturist. "Each time a needle went in a colour flashed in front of my eyes," she recalls. "When all the needles were in it was like watching a movie. I rushed home and realised I could recall enough to paint a part of what I had seen."

Other synaesthetic artists include David Hockney and Wassily Kandinsky, who painted the piece below, entitled Blue. There is still some speculation over whether Kandinsky actually had synaesthesia or was simply influenced by reports of the phenomenon in other people. But to Christopher Tyler of the Smith-Kettlewell Brain Imaging Center in San Francisco, who has analysed Kandinsky's work, it is obvious (Journal of the History of Neuroscience, vol 12, p 223). "It's very explicit in his work and his writings. He went to a performance of Wagner's music and then wrote about how vivid the visual impressions of the horns were and the colour that the music evoked in his mind. That's synaesthesia," he says.

Steen agrees: "I saw a sphere like the one in Kandinsky's Blue in one of my acupuncture sessions. Since it is really hard to explain your visions to someone, I assume Kandinsky was a synaesthete." The striking colour contrast with the red dot is also familiar to her.

These experiences are probably due to extra connections between the auditory and visual cortex, says Jack Cowan, a mathematical neuroscientist at the University of Chicago. He thinks the additional flow of information into the visual cortex overloads its normal inhibitory mechanisms, allowing spontaneous waves of activity that would normally be eliminated to propagate through the brain. These signals may represent shape or colour. Since the brain can't tell whether a signal was generated within the brain or externally, synaesthetes see the shapes as if they came from the eye.