Interesting story today from ABC News on a phenomenon that has interested SC for years, synesthesia.
As SC has always understood it, the claim of synesthetes is that perceptions in one sense trigger perceptions in another sense, even though a non-synesthete wouldn't notice any stimulus of the second sense. So a synesthete listening to a saxophone might perceive the sound as literally being blue in a way which is, at best, only metaphorically true for other people.
But that's not quite what seems to be going on in the experiments described in this article. In an effort to show that words had distinct colors, researchers showed a subject a list of 100 monosyllabic words and asked him to name the colors of each one. Repeating the task a month later yielded enough similarity that the effect was judged significant, and therefore psychologically real.
However, all of the text was printed in black. SC wonders what would happen if the words were printed in different colors. That is, if the word "fish" was printed in red, would the synesthete report that the color associated with it was whatever he had reported before? Or would he say "red" (assuming that's not the one that he had already associated with it)? And if he said "red", would this demonstrate that there was an association between the meaning of the word and the color, the shape of the letters and the color, or would this just trash our understanding of synesthesia altogether? The researchers involved think that the perception of color for words is a glitch in visual processing; if the words were in a specific color other than black, and that color was what people reported seeing, SC thinks this would require assigning the glitch to some other place in the brain.