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Abrie SchroederAbrie Schroeder

Green Giggles: Willamette Students Study Brain Phenomenon

Wednesday is yellow. The letter "a" is red. And some people taste like baked potatoes. For two Willamette University students conducting original research on the brain condition, synesthesia, these responses are not unusual. Their work is shedding light on the mysteries of human consciousness and may one day help us understand debilitating conditions like autism and dyslexia.

Abrie Schroeder, Bend, Ore., and Miranda Scolari, Eureka, Calif., are both seniors majoring in psychology. They are conducting research on synesthesia, a unique neurological condition that gives rise to a mixing of the senses, with Willamette psychology Professor Mark Stewart. In 2003, each received a $3,000 Carson Undergraduate Research Grant, money designed to fund original student research.

"Synesthesia is a blending of the senses," explained Schroeder. "If you perceive something in one sensory modality, you get another perception in a different modality. For instance, you may see a letter or a number and you experience a color. Or you may experience colors with music or taste color or shapes."

One woman the students interviewed experiences people as tastes. She told them when she sees Professor Stewart, she experiences the taste of plain baked potato.

Once believed to be a very rare condition, researchers now think synesthesia is relatively common. "Early research suggested that maybe one in 20,000 people have synesthesia," said Scolari. "More recently, it's one in 200. One researcher even suggested one in 20."

In fact, some people may have synesthesia and not even know it. For them, these "extra" perceptions are normal.

While scientists have known about synesthesia for 300 years, they've only begun seriously researching it in the last few years. That may be because it's difficult to study. For one thing, people who have synethesia (synethetes) fall into two different classes: projectors and associators. "Projectors see a color out in front of them like they're looking through colored glasses," explained Schroeder. "Associator types experience the perception only in their mind's eye."

Within the two major groups, there may be as many as 35 different types. Even with synethetes of the same type, each person's experience is uniquely his or her own. For instance, in people who experience colors with letters, one person may experience the letter "a" as red, while another experiences it as green or as a combination of colors. This means that each experiment has to be crafted for individual subjects - a difficult and laborious task.

The students both chose to study associators, the most common yet least researched type. Scolari wanted to see if the colors (photism) experienced by synethetes have an impact on memory. Schroeder wanted to know whether words could elicit the same colors as letters. Each student interviewed multiple synethetes, chose one, and then crafted the experiment to fit the individual synethete's perceptual experiences.

Scolari's experiment involved recalling lists that contained congruent words, those associated with particular colors, as well as words that were incongruent. "For the woman I was working with, the letter "a" is associated with blue. I'd show my subject a word like "able" colored blue. Then I'd show the word "able" colored yellow. I wanted to know if her photistic experience affected her memory."

She found that the color of the word did impact her subject's ability to remember it. "When I gave her lists of words colored congruently and incongruently and asked her to recall them, she was able to recall the congruent words significantly more easily than the incongruent ones," she said. "Previous research looked at just letters and memory. This research shows that words beginning with particular letters have the same effect."

Scolari also looked at the impact of congruently colored words on the ability to recall missing words in lists of related items like chair, table and recliner, but, to date, her results have been inconclusive.

Taking a slightly different tack, Schroeder wanted to see if words impacted how fast her subject could name particular colors. She found if the letter "g" was perceived as the color blue by the subject, seeing a word like "giggle" containing "g's" followed by a blue color patch (the congruent color) enabled her subject to identify the color rapidly. If "giggle" was followed by an incongruent color patch like yellow, the subject was significantly slower to identify it.

"I found that words elicit photisms," Schroeder explained. "The subject could name the color faster when it matched her letter and color association."

Schroeder also looked at what she called "strong" words, those containing the repetition of letters (e.g. giggle or bubble), and "weak" words, those containing no letter repetition (e.g. blunder). She found her subject was able to respond even faster when the strong words were paired with their congruent colors. Her subject was slowest when a strong word like giggle was coupled with an incongruent color. "Strong incongruent is the most glaringly incorrect in the brain," Schroeder explained. "If the word "giggle" stimulates the color blue and instead I flash yellow, it takes a moment longer for the brain's gears to shift and respond with the right answer."

So why is this work important? For one thing, it helps psychologists understand memory. "Our research has added to what we know about synesthesia and it also tells us more about how memory works," said Scolari. "The data shows that associations play a big part in whether or not we remember something."

Perhaps most importantly, synesthesia gives researchers a unique window into the brain's hard wiring. "Synesthesia is different from some of the other neurological conditions because it isn't disabling," Schroeder said. "It allows us to study neurological cross wiring in people who are functioning just fine with it. It lets us take a look at neurological connections and understand them better. It may ultimately help us understand more debilitating conditions like autism."

These experiments aren't the end of synesthesia research for Scolari and Schroeder. Both students have extended this research into their senior theses. They will attend the Western Psychological Association's conference in Phoenix, Ariz., in April to present their findings. They also hope to write up their work for publication.

For Scolari, who plans to attend graduate school to earn a Ph.D. in psychology, the experience has given her new insight into synethesia and into herself. "By interviewing all these people with synethesia, I've come to see it as an enhanced perception that the rest of us don't possess," she said. "I've also learned that I love doing research. It's exciting. This is what I want to do."

Schroeder says conducting original research has "definitely influenced my career choices. I'd like to take this study as far as I can. I plan to get my Ph.D. in experimental psychology. This is fun for me. It's what I want to spend my life doing."