Let’s do an exercise. Imagine a salad full of bitter greens: radicchio, endive, dandelion greens, arugula. There’s no dressing on this salad. Now imagine taking a big bite of that salad and beginning to chew. Pay close attention to your tongue. As you chew on those bitter greens, is there a particular part of your tongue that feels more active than others? If you were to actually chew on one of these bitter greens, it might become more obvious that our bitter taste receptors reside on the back of the tongue. And when those become activated, a cascade of physiological responses takes place.