Each nostril has a different sense of smell

Unless we suffer from anosmia, all people have Sense of smell. At least that’s what we thought until now; because after the publication of a new study, we can say that there are actually two of them. One for each nostril.

In fact, to be strict, we only have one sense of smell, this is true. But smells are perceived differently through each nostrilso the way our brain interprets it is very different from what we thought.

Something similar had long been suspected thanks to research carried out in mice. However, we now know that it also occurs in humans. The study in question, published in the journal Current Biology, was conducted with a very small number of participants, namely 10. But this is enough to demonstrate that it is actually, and as strange as it may seem, very useful for us as a species.

Left or right smell?

This study was conducted on 10 patients with epilepsy placed in intracranial depth electrodes to determine the origin of your seizures. These volunteers were chosen because the device they were using was not entirely comfortable, so they took advantage of the fact that they had to use it for health reasons unrelated to the study.

With their permission, they took advantage of the fact that they had electrodes to conduct a little experiment with smell. Basically, they were given three different scents (banana, coffee, and eucalyptus) through their nostrils. First both, then the left and finally the right.

Thus, it was seen that when the aroma in question was introduced into both nostrils, activity was generated in two areas: left and right cerebral cortex. However, when it was first introduced into the fossa, only the corresponding hemisphere was activated. A little later, the other half of the brain was activated, but with some delay.

Thus, it was demonstrated that indeed the sense of smell is not holistic, but is distributed along the nasal passages, with the help of which we can sniff on your own.

What is all this for?

All this is beneficial because we can not only catch odors. We also know where are they from. The sense of smell is very necessary for our survival, as well as for the survival of other living things; since, for example, by means of unpleasant odors, it tells us when we should flee from a stimulus. It is for this reason that poisons often smell bad.

This is also something was artificially used. For example, butane has no odor, but an unpleasant aroma is added so that if there is a leak, we can detect it and take action. The same goes for good smells, which bring back memories and can even improve our mood.

Knowing where the smell is coming from is helpful. is it good or bad. Thanks to the proportions of the aroma reaching each nostril, we can know where something is burning or there is a gas leak. And, if we are hungry, the aroma can tell us where the aroma of freshly baked bread comes from, reaching us on the street, and we will go buy it.

We already knew all this. We realized that we could discern where the smell was coming from. But we didn’t think that this is because our sense of smell is different in each nostril. And deep down, we are much less symmetrical than we usually think.