Don’t snort! We really are led by our nose

HAVING two nostrils means a lot more than simply making our faces look symmetrical.

Scientists say that we ‘smell in stereo’ – and this is a sophisticated way for our noses to help us navigate.

This is similar to how we see and hear in stereo with two eyes and two ears.

The advantages for our sight and hearing are clear as it allows us a wider frame of view and the ability to hear what direction a sound is coming from.

When it comes to smell, it had long been believed that humans only sniff in mono as the nostrils are so close together that there seemed no advantage in having a pair.

But having our nose divided in two means we can actually sniff to the left or to the right, not just in one direction. Researchers add, however, that this ability to smell in stereo is a subconscious process which it is impossible for us to put into words or to even know about.

For their study, the scientists in China created a series of experiments for 72 participants. They were shown a pattern of white dots on a black background – called an optic flow pattern – which created an illusion of movement towards them.

Then the subjects had smells of rose and vanilla applied directly into their nostrils. When researchers made the scent more concentrated in one nostril compared to the other, the participants tilted their gaze slightly in that direction.

However, they were totally unaware that they were behaving like this.

The study at the Chinese Academy of Sciences in Beijing concluded that smell could play a greater role in navigation when our sight is affected, such as trying to find our way in the dark.

In contrast, many earlier tests had claimed that it was impossible for humans to detect when a scent was applied to one nostril or the other when the eyes were closed.