It is a globally common fact that the tongue is the main receptor of taste. Through its taste buds, the tongue can detect different tastes, whether sweet, sour, salty, or bitter. However, if you looked all around your office or classroom for example, you would find things like wooden drawers, plastic items, or metal handles. Then, you would come to the realization that your mind is familiar with the taste of each and every item of these, and its taste could be identified without the tongue tasting them. Suddenly, you would come to the realization that you can actually taste your surroundings, where it makes the phrase “It looks so good that I can actually taste it” a scientifically sound saying.
When you order your favourite dessert—one layer of dough, covered with chocolate, and white chocolate drizzles with a side of an ice cream scoop—your brain can determine the taste of this mouth-watering sight without actually tasting it. So, when you take your first bite, the taste is hardly a surprise. This has paved the way for scientists in the last decade to determine how taste is transformed from detection into perception. How does the brain deal with this multisensory experiences that we are subjected to on a daily basis? How can the brain associate the sight to the taste without the tongue tasting it?
As was believed that the taste buds on our tongues send taste information to a part of the brain known as the thalamus. Then, the taste information is sent to the gustatory cortex, which is located between the anterior insula and a structure called frontal operculum.
An illustration of the brain cortex and the taste receptors.
(Source: Neuroscientifically Challenged)
However, scientific research and experimentation have led to a different conclusion. The newest findings discovered that the gustatory cortex is a multisensory cortex, which receives the perception of taste and associates it with difference senses like smell, temperature, and texture. The gustatory cortex receives information from all the senses not just the tongue; it can represent and identify different tastes and associate them with their items.
Neuroscientists at the National Institutes of Health, affiliated to the U.S. Department of Health and Human Services, conducted experiments on mice, which found tastes can be identified with no involvement of the tongue. They have stimulated the brain gustatory cortex of the mice, which is the “bitter” receptor. While there was actually nothing on the tongues of the mice, the team noticed that they pucker up as if they are actually tasting something bitter.
To conclude, the brain is the most complex organ in our body. Scientists do not yet fully-understand all its capabilities and its way of functioning. While the experiment we discussed tricked the mice brains, who knows, may be in the future we, humans, can trick our brains through stimulating the sweet receptor, which could help us satisfy sugar cravings while actually decreasing our sugar intake.
References
Peng, Y., Gillis-Smith, S., Jin, H. et al. Sweet and bitter taste in the brain of awake behaving animals. Nature 527, 512–515 (2015). https://doi.org/10.1038/nature15763
Stony Brook University. (2016, August 31). Brain perceives taste with all senses, scientific evidence reveals. ScienceDaily. Retrieved December 31, 2023 from www.sciencedaily.com/releases/2016/08/160831133706.htm
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