Your nose knows: Nostrils can detect odours independently from one another and can subconsciously guide you to the source of a smell
- Humans posses both pairs of ears and eyes that let us see and hear ‘in stereo’
- Researchers from China set out to find if our paired nostrils play a similar role
- They gave participants a visual test involving determining the motion of dots
- The team found that applying stronger smells to one nostril biased the visual test
Nostrils can detect odours independently from one another and can subconsciously guide you to the source of a smell, a study has concluded.
Researchers from China found that applying different strengths of odour to people’s nostrils in tests subtly impacted their perception of visually-simulated movement.
The findings prove that, even if we are not conscious of it, our sense of smell works ‘in stereo’ — just like our vision and hearing does using our pairs of eyes and ears.
Your nose knows: Nostrils can detect odours independently from one another and can subconsciously guide you to the source of a smell (stock image)
The study was undertaken by psychologist Wen Zhou and colleagues from the State Key Laboratory of Brain and Cognitive Science in Beijing.
‘The human brain exploits subtle differences between the inputs to the paired eyes and ears to construct three-dimensional experiences and navigate the environment,’ the researchers wrote in their paper.
‘Whether and how it does so for olfaction,’ they added, had been unclear.
‘Although humans also have two separate nasal passages that simultaneously sample from non-overlapping regions in space.’
To determine if we can smell in stereo, the team conducted a series of experiments — involving a total of 216 volunteers — in which participants were asked to watch a moving field of dots that simulated motion.
The volunteers were asked to determine which way they were ‘moving’ relative to a fixed cross on the screen while each of their nostrils was exposed to different concentrations of odours.
The researchers found that a stronger concentration of odour in one nostril consistently biased the participants towards thinking that they were moving in that direction — despite being unable to report which side received the stronger smell.
The researchers found that a stronger concentration of odour in one nostril consistently biased the participants towards thinking that they were moving in that direction — despite being unable to report which side received the stronger smell (stock image)
‘The findings indicate that humans have a stereo sense of smell that subconsciously guides navigation,’ the researchers concluded.
A stereo smelling capacity is known to exist in other mammals — including moles and rats.
The full findings of the study were published in the Proceedings of the National Academy of Sciences.