Our research focused on color-graphemic synesthesia: the perception of color when viewing achromatic alphanumeric characters. This appears to be the most common form of synesthesia and provides for some of the more memorable accounts of this unique condition. For example, one individual who sees digits vividly colored volunteered to us that she performed arithmetic using her colors and was surprised when she first learned that others did not: “I thought everyone did math with colors – that yellow plus yellow was red for everyone.” Another individual complained that she often confused appointments scheduled for Tuesday or for Thursday, because both days are “red.” Still another confessed to an unfounded dislike of the city of Houston “just because the word was an ugly shade of brown” and another acknowledge that “my husband knows that I couldn’t have married him if his name had been the ‘wrong’ color for me … we are, color-wise, perfectly compatible.”
In a series of experiments, we demonstrated the perceptual reality of synesthetic colors. For lexical-chromatic synesthetes who report seeing their colors “on the page” rather than “in their mind’s eye” (also referred to as a distinction between projector versus associator synesthetes), synesthetic colors produce qualitatively similar psychological effects as real colors.
Kim, C.-Y., Blake, R., & Palmeri, T.J. (2005). Perceptual interaction between real and synesthetic colors. Cortex.
Blake, R.B., Palmeri, T.J., Marois, R., & Kim, C.-Y. (2003). On the perceptual reality of synesthetic color. In L. Robertson & N. Sagiv (Eds.), Attention on Synesthesia: Cognition, Development, and Neurobiology.
Palmeri, T.J., Blake, R.B., & Marois, R. (2002). What is synesthesia? Scientific American On-Line. [web page]
Palmeri, T.J., Blake, R.B., Marois, R., Flanery, M.A., & Whetsell, W.O. (2002). The perceptual reality of synesthetic color. Proceedings of the National Academy of Sciences, 99, 4127-4131.