We all are familiar with the 'tongue map' concept which says we have got different areas of tongue that senses different tastes. It also says that there are four primary tastes namely sourness, sweetness, saltiness and bitterness. See the figure. It shows the areas on our tongue which are supposed to receive these primary tastes.
But how many of us know that it is utterly a false idea? Yes, of course it is. This century old misconception comes from the research paper of a German scientist D. P. Hanig published in 1901. Probably, it is the most popular false idea ever presented and Hanig owns the credit of misguiding generations for a century! It was only in 1974, Virginia Collins re-examined Hanig's findings. She does agree to Hanig in one concept; there are variations in sensitivity to the four basic tastes. But it is too small to have any practical significance. Collings found that all tastes can be detected anywhere there are taste receptors—around the tongue, on the soft palate at back roof of the mouth, and even in the epiglottis, the flap that blocks food from the windpipe.
Another fact is, other than sweet, sour, salty and bitter, there is another fifth distinct taste. It can be called 'meaty' which is the taste associated with meats. It is the taste of glutamate.
It is a mystery why scientists didn't bother about this seemingly simple idea until 1974 and why on earth the text books print this idea even today. [Read more]