Taste Adaptation

Although the saliva that constantly bathes our tongue contains a number of taste stimuli, we ordinarily find it quite tasteless. However, if you were to rinse your tongue with water for a minute or so, you would find your own saliva to have a distinctly salty taste. And if you rinsed the tongue with a salt solution only somewhat saltier than your saliva, pure water would then taste distinctly sour-bitter. Thus, the tongue is constantly adapts to the stimuli that surround it and responds to changes from the adapting level. The range over which adaptation is complete is at least two orders of magnitude, or more than 100 to 1.

As in all the senses, adaptation in taste has many important functions. Most obvious is the ...