Unpalatable

Remember being taught at school that different areas of the tongue is responsible for different tastes? That is, there's a region for sweet which can't taste bitter, and so on. There were "maps" made showing these regions.

Well, it turns out to be baloney. All taste buds can taste all tastes. An easy proof comes from people with damages tongues. Say one lost the area which was supposed to taste salt. When tests were done, they still could but with a different area.

Its not beyond the realms of possibility to test this yourself with a healthy tongue and a pippet.

So where did this idea come from - and how way the map created?

Sweet, salty, bitter, sour ... umami?

The tongue map was shown to be incorrect a long, long time ago, so why is it still around? The receptors which are able to differentiate the different tastes are equally distributed all over it, but the traditional map shows otherwise. It started in 1901 when the German scientist David P Hänig produced a study on this called Zur Psychophysik des Geschmackssinnes. He documented the results of his experiments, which showed (correctly) that the edge of the tongue was more receptive to taste than other areas, but it turns out that's only because there are higher concentrations of taste buds there. he also missed out completely a taste variation: umami. It's classed as the fifth taste after salty, sweet, bitter and sour.

Experiments have been conducted where the nerve connecting specific areas of the tongue had been temporarily anesthetised, yet the subject was still able to taste normally - in some cases even more intensely, which caused a little confusion.

In the 1940's the map was redrawn again, and it's this one everyone is the most familiar with. Edwin G Boring, in his book Sensation and Perception in the History of Experimental Psychology, depicted clear demarcation lines between the taste areas, and had no scale. What is often overlooked is that other areas of the mouth such as the roof and sides can also taste. With all this evidence available, why is the map still to be found in schools? Whilst this isn't a regular Mandela Effect, it is an MMDE because it is so widely believed.