Synaesthesia is a genetic condition in which one sense triggers another. In the most common version of the phenomenon, words or numbers trigger colors, Dr. Julia Simner studies a very uncommon form of synaesthesia, in which words trigger tastes.
Synaesthesia is believed to effect about one out ever 23 people, with sensations that are automatic and cannot be turned on or off. People are generally born with the condition, which is not considered at all harmful, and it runs in families. Most synaesthetes could not imagine life without these extra sensations. Studying synaesthesia may help us to understand how the brain segregates and integrates different sensations and thoughts.
For more information and to get the perspective of a synaesthete, link to this supportive and informative website.