- Education and Science
Tasting - How Do We Taste?
The sense of taste, or gustation, is part of the central nervous system. It allows us to detect the flavour of foods and other substances.
Being able to taste protects us from eating unsafe foods. It also helps us to balance our diets with different nutritional requirements.
The sense of taste is greatly enhanced by the sense of smell, and by feeling the texture and physical/chemical temperature of foods. In fact, the experience of flavour is really a combination of a number of senses besides taste.
Inside the mouth there are approximately ten thousand taste buds (also called gustatory calyculi). These are found mainly on the tongue, on or around small lumps called papillae, as well as on the soft palate, epiglottis and pharynx. Until recently, scientists believed that each of these taste buds were able detect five basic taste sensations. These are sweet, sour, salty, bitter and unami (savoury). New research demonstrates that it is, in fact, the brain (not the tongue) that interprets stimulation as these different tastes.
Each taste bud contains about fifty to one hundred receptor cells. Each of these cells has a long, hair-like protrusion that extends from a small opening where it comes into contact with food chemicals it finds dissolved in saliva. Once stimulated, these cells send nerve impulses to the brain, where the signals are interpreted in several areas of the cerebral cortex.
The Taste Myth
It is often thought, and was even taught in schools for many years, that certain areas of the tongue specifically detect certain tastes. This was found to be incorrect. Instead scientists believed that, while there were apparently some tiny differences in sensitivity in certain areas of the tongue, they were only very slight and are barely significant. They believed that, in general, taste buds in all areas of the tongue could uniformly distinguish the basic tastes.
The most recent research shows that taste is determined in the brain, not by the tongue. Scientists have demonstrated that they can fool mice into thinking that they are tasting something different by manipulating the brain cells.