Do Different Parts of the Tongue Taste Different Flavors?

Depending on how old you are, you may have encountered an image like this one in a school science lesson. This “tongue map” locates taste receptors for sweet, salty, bitter, and sour flavors on different parts of the tongue, implying that different areas detect different flavors. (Many maps add a fifth flavor, umami, though it wasn't part of the original design.) But that interpretation of the “tongue map” is actually a myth. You can even disprove it at home: if you put lemon juice on the so-called “sweet” section of your tongue, it still tastes sour. And placing a piece of cotton candy on the “salty” area doesn’t stop it from tasting sweet. So where did this myth come from? Well, the creator of the tongue map didn’t intend to suggest that taste receptor cells are limited to specific regions of the tongue. He was actually measuring flavor sensitivity. It’s true that the tip of the tongue has a lot of “sweet” taste receptors, and so is more responsive to sweet flavors than the sides or back are. But that doesn’t mean the tip of the tongue can only taste sweet flavors. It still has taste receptors for salt, bitterness, sourness, and umami, too! So how does your tongue actually taste different flavors? Taste receptor cells occur on the tongue in diverse groups of 50 to 150, and each of these groups form a taste bud. The average human tongue has anywhere from 2,000 to 8,000 taste buds—and, because of those different receptors, they can all taste more than one flavor.