Synaesthesia, in which one or more of our senses is stimulated by another, has long been recognized; now, for the first time, it has been shown to assist in the performance of a cognitive task. Lutz Jäncke and his colleagues at the University of Zürich have been studying a musician who not only sees colours when she hears a particular note — a fairly common form of synaesthesia — but also tastes them.

For Elizabeth Sulston, different tone intervals have different tastes, including salty, creamy and that of mown grass. She says of her synaesthesia, “I ... really became conscious of it at sixteen. Then I started to use it for the tone-interval identification” (news@nature.com, 2 March 2005). And, according to Michaela Esslen, one of Jäncke's co-workers, “She doesn't imagine the taste, she really tastes it” (ABC.net, 3 March 2005).

Jäncke and his colleagues compared her ability to correctly identify a tone interval with concurrent delivery to her tongue of either the taste she normally associates with that interval or a conflicting taste. Although incongruent tastes did not result in incorrect answers, they did affect the speed at which she was able to answer. Furthermore, the correct taste allowed her to recognize an interval more quickly than five non-synaesthetic musicians.

How this discovery might relate to the wider field of neuroscience is not certain. Jäncke points out that associations can aid memory, and adds, “It may also demonstrate that synaesthesia may be modified for learning and used for other things” (news@nature.com).