In brief: How does our sense of taste work? InformedHealth org NCBI Bookshelf

The other primary chemical sense, taste (technically, the gustatory system), responds to molecules dissolved in liquid. Foliate papillae can also be seen with the naked eye on the edges of the tongue at the back of the mouth. Our tongue has about 20 foliate papillae on it, each of which has several hundred taste buds. The substance responsible for this taste is the salt crystal made of sodium and chloride. Mineral salts such as those containing potassium or magnesium can also cause a salty taste. Less than 1 per cent of British people, in one study, chose smell as the most important sense.

For a single molecule, the pattern of activation across the glomeruli paints a picture of the chemical structure of the molecule. Thus, the olfactory system can identify a vast array of chemicals present in the environment. Most of the odors we encounter are actually mixtures of chemicals (e.g., bacon odor). The olfactory system creates an image for the mixture and stores it in memory just as it does for the odor of a single molecule (Shepherd, 2005). Our journey through the neural pathways of taste and smell has been quite the adventure, hasn’t it? So the next time you catch a whiff of something delightful or taste something exquisite, give a little nod to your hardworking brain.

4 Tasting, Smelling, and Touching

Taking this work further, Zuker co-led a study published in 2015 that manipulated the bitter and sweet areas of the understanding of taste and smell gustatory cortex in mice. When the mice were given plain water whilst their bitter areas were being stimulated, they behaved as though the water tasted unpleasant. The opposite was observed when it was the sweet area of the cortex being stimulated.

Perceptual independence from salty and sweet taste

It’s not just about losing taste; it’s about losing an entire sensory experience. This particular sensation, called chemesthesis, is not a taste in the technical sense, because the sensation does not arise from taste buds, and a different set of nerve fibers carry it to the brain. Foods like chili peppers activate nerve fibers directly; the sensation interpreted as “hot” results from the stimulation of somatosensory (pain/temperature) fibers on the tongue.

So I’m sure that in the next few years there will be more medical therapies to help people recover the sense of smell. But for those of us who do have a functioning sense of smell, becoming more aware of nuances in cooking and wine and food and drinks, cultivation and appreciation. Those are things that I think anyone can get better in that sense. The first thing that someone does when they pull something out of the fridge that they’re not sure of, is they ask their partner, can you smell this? But on the flip side of that, do human beings have a good sense of smell. Because, I don’t know, I look around the animal world, just even my dog I was walking this morning.