What does a change in temperature taste like? According to a study by Yale investigators, the same salty, sweet or sour tastes that are normally caused by food, drink and other chemical substances on the tongue.

“We’ve discovered that specific tastes can be produced by temperature stimulation, just as certain chemicals can evoke only certain taste qualities,” said Barry G. Green, Ph.D., professor of surgery in the section of otolaryngology and a fellow of the John B. Pierce Laboratory, who directed the study. The paper, which was published in the February 24 issue of Nature, is the first to show how the brain interprets thermal stimulation of the tongue. The investigators cooled and warmed various areas of the tongue under precisely controlled conditions to study what taste sensations subjects experienced.

Individuals perceived “thermal taste,” as it is called, differently on different parts of the tongue. Warming the front of the tongue induced sweetness and cooling it produced a salty or sour taste, while chilling the back of the tongue created a sour or bitter sensation. However, not everyone experiences thermal taste and the exact temperature conditions needed to produce it are rarely encountered in daily life.

The close relationship between temperature and taste qualities suggests that receptors in the tongue that respond to chemicals have certain properties that make them vulnerable to specific kinds of temperature change. This information may provide clues to understanding the nature of these receptor processes, as well as potential therapies for when they go awry.