BioEd Online

A recorder player has fascinated neuroscientists with her ability to taste differences in the intervals between notes.

The condition in which the brain links two or more of the senses is known as synaesthesia, and some sense combinations are relatively common. But this is the first time that the ability has been found to help in performing a mental task, such as identifying a major third.

Elizabeth Sulston was at school when she first noticed that she saw colours while hearing music. She realized that the same was not true of her peers, although linkage of tone and colour is a known synaesthetic combination.

As she began to learn music more formally, she found that when hearing particular tone intervals she experienced a characteristic taste on her tongue. For example, a minor third tasted salty to her, whereas a minor sixth tasted like cream. She started to use the tastes to help her recognize different chords.

Talking to news@nature.com, she says: "I always had the synaesthesia, but really became conscious of it at 16. Then I started to use it for the tone-interval identification. I could first check it by counting the space between the notes, and second by 'feeling' my tongue."

The taste of music

Lutz Jäncke, a neuroscientist at the University of Zurich, Switzerland, works with musicians who report unusual qualities or skills. Thanks to a student investigating synaesthesia he was introduced to the recorder-playing Sulston.

To test her unique ability, he and his colleagues played tone intervals while delivering different tastes to her tongue. They used either the same taste that Sulston associates with an interval, or a clashing one ( see box).

They found that she was able to identify the intervals much more quickly when the taste matched the one that she says she normally associates with it. That kind of pattern would be difficult to fake, Jäncke says. He reports the results in Nature¹.

"With incongruent taste she was sometimes slower than other musicians; she is extraordinarily quick usually," he says. "The synaesthesia is kind of boosting her performance. Her hit rate was perfect, but the difference was in the reaction times."

Learning analogue

When asked whether Sulston's ability has any wider implications for neuroscience, Jäncke laughs. "This is the million-dollar question!" he says.

"One might speculate that this could be a good analogue for learning: our skills are improved if we associate the item we learn with many other items. It may also demonstrate that synaesthesia may be modified for learning and used for other things."

For Sulston herself, the benefit comes simply from the way that she experiences music. "I can imagine that someone who has no synaesthetic perception does not have such an intense sensation as I do when listening to music," she says.

"Music is richer. It is difficult to say whether I would have become a musician if I was not synaesthetic."