Beyond its apparent modesty, the human nose hides astonishing abilities to detect the subtleties of odors. Contrary to what we thought, our olfactory sense reacts with a speed comparable to that of vision andhearing.
In a study published in Nature Human Behaviourresearchers used an innovative device to test olfactory perception in 229 adults. In exponent mixtures of odors with precise delays, they demonstrated that participants could distinguish variations in just a few tens of milliseconds. This result challenges our understanding of the speed of our sense of smell, suggesting a temporal code for identifying odors, similar to that used to perceive colors.
Through several carefully orchestrated experiments, researchers developed an innovative device capable of presenting odor mixtures with pinpoint precision, namely delays as short as 18 milliseconds. This technology made it possible to rigorously control when each odor was released into the air, ensuring that participants inhaled the scents in a specific order. Thanks to this device, it was possible to observe how individuals could distinguish not only the odors themselves, but also the order in which they were presented.
Even when the temporal differences between the two scents were minimal, participants demonstrated an impressive ability to correctly identify which scent was perceived first. Indeed, while previous research suggested that the time required to perceive two odors was 1200 milliseconds, the tests carried out in this experiment revealed that the nez human was able to distinguish two different odors with a latency of only 60 milliseconds between these two odors.
This precision revealed unexpected olfactory sensitivity, highlighting the efficiency with which the human nose can analyze and interpret complex chemical signals in a very short period of time.
The implications of these discoveries go far beyond just science. They could profoundly change sectors such as the food industry, perfumery and even medicine, offering new perspectives for the development of advanced olfactory technologies.
The researchers also envision potential applications in olfactory rehabilitation for people with loss of smell, as well as in the design of sensory virtual reality systems.
What is olfactory perception?
Olfactory perception is the ability of brain to interpret the odorous molecules captured by the nose. When a person inhales, olfactory receptors in the nasal cavity detect chemical compounds in the air. These signals are then sent to the brain, which translates them into odor sensations.
The brain uses a “time coding” mechanism to identify odors. Each odor corresponds to a particular combination of molecules captured by different receptors. This temporal coding allows the brain to quickly differentiate between nearby odors, even when they are perceived in just a few milliseconds.
