Different Parts of Your Tongue Detect Different Tastes.
Lots of people think different parts of the tongue are fine-tuned to detect different tastes. The tip of the tongue is where you get your cupcake on, the sides are where the salty taste really hits home, bitter's in the back, and in between is the sour zone. This "fact" was the prevailing notion for a very long time. It has persisted in spite of millions of kids in health class insisting that the wooden spoon just tastes like wooden spoon, no matter how they lick it.
More recently, however, we've found out that the whole zones theory was pretty much bologna. (That would be the umami talking. More about that in a sec.) It turns out people can sense different tastes all over their tongues. There are a few outliers, but for most people, them's the facts.
Then there's the fifth basic taste that doesn't get a lot of PR, and that's umami. Auguste Escoffier, the pimpest chef in 19th century France, concocted this fifth wheel in the palate party. Foodies swooned over it – it's been described as savory and meaty – but scientists stuck to the sweet/salty/bitter/sour taste tetrahedron.
Even though umami was a familiar taste in Japan, the "fifth taste" idea didn't get much traction there, either. That is until Kikunae Ikeda, a whiz-bang Japanese chemist, decided to get to the bottom of what umami was all about. He figured out the taste came from glutamic acid, and he called it the Japanese version of yummy.
No one at the time believed him, though, and it wasn't until the end of the 20th century that scientists decided to look into it. They realized Ikeda was right all along.