World Science Festival: What is Color?

“What is Color?” was the dominant question submitted by more than 26,000 curious eleven-year olds around the world in this year’s Flame Challenge, issued by the Alan Alda Center for Communicating Science at Stony Brook University. The Challenge asks scientists to answer the chosen question in a manner understandable and engaging to eleven-year olds (past questions were: What is a Flame? What is Time?), and this year, almost 400 scientists responded. The 2014 winners were announced on Sunday.

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Brain Oddities: Mmm…tastes like blue.

This is the first in a series on unique and zany neuroscience topics. Enjoy Brain Oddities!

Wolfgang Amadeus Mozart began playing the piano at the age of three. By age five he was composing short songs that he would play for his father. At eight, he composed his first symphony, and at 14 he was commissioned to write his first serious opera. What a know-it-all, right?

By the age at which Mozart had composed his first symphony, I had begun struggling with classical guitar, awkwardly picking out “Hot Cross Buns” on nylon strings. Curiously, I took up guitar by choice, unlike a friend of mine who was forced into piano lessons and would cry under the piano bench until her teacher left in frustration. Despite my willing foray into the world of classical music (“Hot Cross Buns” notwithstanding), I composed no symphonies or operas. I advanced along in a slow and steady manner until I abandoned classical music altogether for the easy strum of acoustic guitar. Perhaps, if while hearing “Hot Cross Buns,” I saw the colors red, green, and blue, I would not have so easily relinquished my classical music education.

A couple of years ago I learned of an unusual, although not particularly rare, condition called synesthesia. Clinically defined, synesthesia is an involuntary experience wherein stimulation of one sensory modality causes activation in a second, unstimulated modality. In other words, the brain confuses the senses. Mozart, and a handful of other famous composers, was said to have chromethesia, a specific form of synesthesia in which one “sees” musical notes and chords as colors or shapes. To what extent chromethesia aided Mozart in his composition is unknown, but I would be lying if I said I didn’t feel a twinge of jealousy when I learned of his alleged condition. Forget owning a TV!

But chromethesia, as I mentioned, is a very specific form of synesthesia and does not represent the condition as a whole. I recently read a paper about two case studies by V.S. Ramachandran and his colleague David Brang of two young women who experience tactile-emotion synesthesia—that’s right, certain textures give them feelings.

Each time these women touch a particular texture, they involuntarily experience a particular emotion. Some textures evoke very primal emotions, such as disgust or joy. Others elicit more subtle feelings, such as guilt. For example, one subject (referred to as “AW” in the paper) experiences strong feelings of depression and worthlessness at the texture of denim. How awful is that! I practically live in jeans. She recalled that she would throw tantrums when her parents forced her to wear jeans to school. As a compromise, she wore black jeans, because something about the color of blue jeans heightened her emotional experience.

I know what you’re thinking—they’re faking. I thought so too, but repeated tests of more than 20 textures (including three different grades of sandpaper, which evoked in AW the emotions guilt, telling a white lie, and relief from most coarse to least coarse) showed the emotional responses to be constant. Furthermore, Ramchandran and Brang measured the women’s skin conductance response (SCR), which can’t be faked. Basically, the SCP is a measure of how sweaty your hands get, an indication of a negative reaction such as stress or fear. The SCR reflected perfectly the women’s reported emotional reactions. And the blue versus black jeans thing? Well, the emotional response was elicited even when the women couldn't see the material, but being able to see it affected the emotional reaction. Even more interesting, there were some textures that did not evoke any emotional response, such as human skin or plastic paper clips.

The exact cause of synesthesia is not yet known. However, imaging studies have shown that, in word-color synesthetes for example, hearing a word leads to abnormally high activation in the region of the brain associated with color processing. Ramchandran and Brang have suggested that this may be caused by a cross-activation of early sensory areas (the parts of the brain that initially process sensory input, like smell, before you even become conscious of it), thus the involuntary aspect of synesthesia. How and why this happens is yet to be discovered.

Despite reading about the horrific induction of feelings of worthlessness by denim (my suggestion for tactile-emotion synesthetes: a full-body suit…made entirely of plastic paper clips), I still kind of wish I had synesthesia. When I said this to a friend of mine, she responded, “Yeah, me too. But what if you, like, fell in love with someone whose name tasted like a food you hated? Or WORSE,” she exclaimed, getting excited now, “what if you fell in love with someone whose name tasted like your favorite food, and then they broke up with you??”

Just some food for thought. Or sight.

—Caitlin Schneider

 Sources:

Eagleman, D.M. and Goodale, M.A. (2009). Why color synesthesia involves more than color. Cell Press, 288-293.

Ramachandran, V.S. and Brang, D. (2008). Tactile-emotion synesthesia. Neurocase, 14(5): 390-399.

 

When senses combine

Synesthesia is a phenomenon in which people’s senses seem to be crossed. Some people with the condition can feel tastes or see sounds; others taste voices (think of the opposite of anesthesia, literally “no senses”). Neurologist Richard Cytowic has studied such people for more than three decades, starting with a man in the rare latter category.

“Some people are born with two or more senses hooked together,” Cytowic told an audience of around 120 people at the Library of Congress on Oct. 30. For example, for the first synesthete he studied, some flavors “were more than a mouthful.”

Synesthesia experts estimate that one in 23 people has some form of this involuntary sense-mixing. Some scientists working with infants theorize that all babies are born synesthetic but lose the trait at around three months, when their sense networks start to firm up.

In 1979, when he was a young researcher, Cytowic said, no one had heard of synesthesia, and if they had they thought it wasn’t real. But he was hooked—“it interested me to explain a subjective experience that seems impossible to prove.”

He and others eventually did prove it, through well-designed experiments and a mass of data from people who started calling and writing to describe their experiences. Now “a new generation in 15 countries” studies the trait, from its individualistic expression in behavior to its possible molecular and genetic components.

“Five groups around the world are working on analyzing for the synesthesia gene,” he said. Researchers currently think the trait is genetic (“hyperconnectivity between disparate brain systems”) but requires early exposure to over-learned groupings. For example, many synesthetes see colors or shapes related to such sequences as days of the week, calendars and other common number forms, including music. (Are you synesthetic? Take a computer-based test at http://www.synesthete.org/.)

Cytowic played two short films to help illustrate the ability. The first paired Chopin’s Valse Brillante with a moving pattern of dashes of color changing in time with the music. The second, a short film by Terri Timely seen below, cleverly captures the idea of living with many forms of synesthesia, Cytowic said. One difference, though, is that instead of the discrete objects such as cats seen in the video, synesthetes are more likely to see general shapes or colors.

Crossing sense pathways can run in families and seems to be more common in artistically creative people, Cytowic said. Examples include writers Douglas Coupland and Vladimir Nabokov (and his family); artists David Hockney and Wassily Kandinsky; musicians Olivier Messiaen, Itzak Perlman and Billy Joel; and performer Marilyn Monroe. Stevie Wonder also has a form of sound-color synesthesia. “Synesthesia is very common in blind people because you don’t need your eyes to see—you see with your brain,” Cytowic said.

Their experiences are not always positive, though. One audience member described herself as a mild sound-taste synesthete and her son a stronger one. One year at school, she said, her son found that his new teacher’s voice “brought a bad taste to his mouth” to such an extent that she had to arrange to move him to a new classroom, “and it was ridiculously difficult. Nobody believed it” when he kept saying “her voice makes me sick.”

Sometimes it’s a synesthete’s friends and family who need to close their eyes. Cytowic told of a taste-color synesthete who had to wait until his wife was out of town to eat a favorite, “very blue,” dish: baked chicken Alaska drenched in orange juice and topped with ice cream.

“Synesthetes have taught us that cross-talk is the rule, not the exception,” Cytowik said. “Minds that work differently are not that different at all, and we can learn from them.”

With David Eagleman, Cytowik co-authored Wednesday Is Indigo Blue: Discovering the Brain of Synesthesia, which was recently reviewed in Cerebrum. His lecture is part of the “Music and the Brain” series, presented by the Library of Congress and the Dana Foundation. The next event, on music and trance states, is tonight; a lecture on dangerous music takes place Friday, Nov. 6.

—Nicky Penttila

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