Solid Geekery

What color is the text you are reading right now?

Black? Red? Blue? A mixture of many colors? Do you see a buffalo?

If you see plain boring black, then you do not have grapheme-color synaesthesia. Don’t feel bad, I don’t have it either, which is why I can say for sure that this text is actually black. To a person who experiences this phenomenon, the words would not be black but awash with color, sort of like this: SYNAESTHESIA (by the way, if you answered “buffalo”, seek help immediately because your brain could be diseased).

Sensory multitasking

The word synaesthesia alone refers to the cross-activation of the senses; when one sensory modality is activated, then another is involuntary activated as well. In short, the brain of a synaesthete perceives the world in a different way, like seeing words and letters in color when they are not in color at all. It is thought to occur in low percentages (some estimates put it around 4% of the population) but researchers think it is actually more prevalent but not reported because many individuals think their synaesthetic experience is normal.

The most commonly known form of synaesthesia is grapheme-color, where individuals perceive letters (and sometimes numbers) in color. For the non-synaesthete such as myself, it’s hard to understand such a concept. Cassidy Curtis has an interesting website explaining and illustrating what this experience is like and shows how the alphabet is represented in different colors.

But there are other types of as well. In sound-color synaesthesia, sounds or tones can cause the individual to experience color. In color-olfaction synaesthesia, a smell can evoke the perception of color. Tastes can evoke colors as well, as in color-gustation synaesthesia. More recently, Blakemore et al. reported on a person who experiences vision-touch synaesthesia, where upon “the visual perception of touch elicits conscious tactile experiences in the perceiver” (see abstract here). This study illustrates the first evidence of such an experience, proving that even though synaesthesia research is a hot area right now, there are still plenty of possible unknown types lurking out there.

Okay, but how do you know they aren’t faking

I asked the same question when first learning about synaesthesia. I naively thought that any person with an active imagination and some useless time on their hands could convince another that they have synaesthetic experiences. Using my fabulous networking skills, I contacted a researcher who studies synaesthesia to ask this very question. The answer, it seems, lies in the ability of synaesthetes to report their experience consistently across time, even years after originally being tested. And those who see colors often describe them in vivid and invariable detail, not just in the primary ROYGBIV spectrum. Brain studies later confirmed that synaesthetes had different brain activation patterns compared to that of nonsynaesthetes and this, like the description of their experiences, was also consistent across time. There is plenty of amazing research being done on the synasthetic brain, much more than I can summarize but you might find these websites helpful on a basic level (macalester.edu/psychology; Ramachandran and Hubbard).

Want to know more?

The University of Sussex has a great Q&A page on their website covering everything from the common types of synaesthesia to how the brain is involved in the synaesthetic experience (hint: it’s thought to be due to the brain cross or rewiring).

Trends in Cognitive Neuroscience ran an interesting review article last year chronicling how synaesthesia could help understand normal and abnormal brain cognition (Kadosh and Henik, 2007).

Synesthete.org has a battery of tests to find out if you are a synaesthetic individual. And by the way, if you are, I am dying to know what a synaesthete experiences in our sensory world. So send us your own stories or any websites you find interesting!

Now go taste some colors!

Blakemore SJ, Bristow D, Bird G, Frith C, Ward J. Somatosensory activations during the observation of touch and a case of vision-touch synaestheria. Brain. 128, 1571-83.

Kadosh RC, Henik A. Can synaesthesia research inform cognitive science? Trends in Cognitive Neuroscience. 11. 177-84.

Ramachandran VS, Hubbard EM. Synaesthesia - a window into perception, thought and language. J. Consciousness Studies. 8, 3-34.