Synesthesia (also spelled synæsthesia or synaesthesia, plural synesthesiae or synaesthesiae), from the ancient Greek σύν (syn), "together," and αἴσθησις (aisthēsis), "sensation," is a neurological condition in which stimulation of one sensory or cognitive pathway leads to automatic, involuntary experiences in a second sensory or cognitive pathway.
For decades, scientists who heard about synesthesia hearing colors, tasting words, seeing colored pain just shrugged their shoulders or rolled their eyes. Now, as irrefutable evidence mounts that some healthy brains really do this, we are forced to ask how this squares with some cherished conceptions of neuroscience. These include binding, modularity, functionalism, blindsight, and consciousness. The good news is that when old theoretical structures fall, new light may flood in.
Only about 3 percent of the population claim to experience some form of synesthesia, but nearly half of those report having a close family member whose senses become similarly entangled. “We know that synesthesia tends to travel in families,” says experimental psychologist David Brang of the University of California, San Diego who, along with V.S. Ramachandran, discusses synesthesia genetics in an article published online November 22 in PLoS Biology.
"The study of synesthesia [has] encouraged people to rethink historical ideas that synesthesia was abnormal and an aberration," says Amy Ione, director of the Diatrope Institute, a California-based group interested in the arts and sciences.
The cause remains a mystery, however.
According to one idea, irregular sprouting of new neural connections within the brain leads to a breakdown of the boundaries that normally exist between the senses.
"You know the word anesthesia, which means no sensation," explains Cytowic. "Synesthesia means joined sensation, and some people are born with two or more of their senses hooked together so that my voice, for example, is not just something that they hear, but it's also something that they might see or taste or feel."
Now in 2005, we believe that this ability called Synesthesia is perhaps not as rare as it was once believed to be. Though synesthesia has been known for the past 300 years, it is only in the last two decades or so that it has been seriously studied by scientists. Two developments have greatly contributed to this greater awareness and attention to synesthesia: the development and use of fMRI scans, and the Internet.
While synesthesia can occur in response to drugs, sensory deprivation, or brain damage, research has largely focused on heritable variants comprising roughly 4% of the general population. Genetic research on synesthesia suggests the phenomenon is heterogeneous and polygenetic, yet it remains unclear whether synesthesia ever provided a selective advantage or is merely a byproduct of some other useful selected trait.
"There are certainly similarities between the descriptions of the meditators' perceptions and those of synesthetes," Dr. Bushell says. "This subject is greatly intriguing and drives my research, though I'm not ready in either case to say what these phenomena ultimately ‘are'-in the language of the philosophy of science, what the ontological or ‘ontic commitments' of them are-nor what their relationship to the particulate nature of reality is in contemporary physics. I and my colleagues are continuing our explorations in this area."
The words "can you paint with all the colors of the wind?" in the chorus felt too organic, too literal, too truly synesthetic to me to be contrived. Someone who could imbue the wind with color and imagine someone painting with it was not just a poet, but a synesthete, I was sure. So I reached out to the song's lyricist Stephen Schwartz, who has also given us Pippin, Godspell, Wicked and many other iconic compositions to see if my hunch was right.
Synesthesia, you probably know, is an effect wherein the stimulation of one sense causes automatic sensations in another sense. For example, grapheme-color synesthesia is where numbers or letters appear to those observing to be shaded or tinged with different colors.
In 2001 Japanese game designer Tetsuya Mizuguchi set out to create a video game that would allow anyone to experience the sensation of synesthesia. The game he and his team produced is called “Rez.” At first glance it appears to simply be an action game set in a virtual computer world. But in fact, it’s much more.