Molecules and nostalgia. A short guide to smell and taste

Compared to vision and hearing, other senses haven’t got as much attention until now. Covid-19 made us realize the importance of smell and taste. Let’s see how they work.

Molecules and nostalgia. A short guide to smell and taste

Smell and taste: how are they important?

Some Covid-19 symptoms made people understand the importance of vital senses—smell and taste. Without them, we cannot enjoy our food or notice if it’s expired. They can warn about dangers: like a sudden fire or gas leakage, thus allowing us to react immediately and save our lives. 

The simple pleasures of smelling a flower bouquet or tasting a slice of pizza also become unavailable.

But how much would a day without smelling and tasting change our lives?

Next up, we’ll discover: Why do people perceive smells and tastes differently? How do molecules in the air become the information in the brain? Why do certain smells cause nostalgia? Is it possible to train yourself to become a perfume expert—or is it an innate ability?

How smell works

How do we use the sense of smell?

Six primary senses complete our self-image: the nervous system gathers information from the sensory cells, transforms it into electric impulses, and delivers it to the brain. Each sensory channel is related to a separate kind of receptor. Taste and smell function by chemoreceptors that detect molecules in the food or the air. 

We get 70–80% of the information about the surroundings through our eyes, which makes sight the most important channel by far. Smell and taste combined provide only 12%, although losing these senses can cause severe discomfort.  Anosmia, the loss of smell, is caused by head traumas, brain injuries, or respiratory infections. It is also one of the symptoms of coronavirus.

Adults can distinguish up to 10 000 various smells. However, the olfactory sense is the sharpest at birth. Our perception of odors changes over time and can even disappear with aging.

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