Your nose may be more powerful than you think.
With a single sniff, the human sense of smell can distinguish odors in fractions of a second, operating at a level of sensitivity that is “similar” to the way our brain perceives colors, “dispelling the widely held belief that smell is the slow our sense.” ”, finds a new study.
Humans can also discriminate between different sequences of odors – they distinguish an ‘A’ sequence before ‘B’ from a ‘B’ sequence before ‘A’ – when the gap between odor A and odor B it’s just 60 milliseconds, according to the study, published Monday in the journal Nature Human Behavior.
“We were surprised to find that participants could distinguish between two odors presented in one order and another in the reverse order when the latency between the odors was just 60 milliseconds,” said Dr. Wen Zhu, lead author of the study, via e- email. Study and principal investigator at the Chinese Academy of Sciences in Beijing. Latency refers to the amount of time that elapses between the delivery of each scent. “For comparison, the duration of a blink is about 180 milliseconds,” Zhou added.
“Our device could be used for therapeutic purposes, such as olfactory training for patients with olfactory loss,” said Zhou. “More broadly, our findings could guide the design and development of electronic noses and virtual reality olfactory systems, which could bring important clinical benefits.”
The study
The researchers, from the University of the Chinese Academy of Sciences and Ohio State University, developed an odor-activated device that included check valves – devices that allow odors to flow in one direction – and Teflon tubes capable of transporting odors to the human nose. with an accuracy of 18 milliseconds. The researchers asked 229 adults in China to wear this device and smell different odor mixtures: two odors presented in quick succession in a single puff.
The odors included apple scents, sweet floral scents, lemon scents, and onion scents. The delay between the two odors was carefully manipulated. The researchers analyzed whether participants could discriminate between two odors presented in one order and another in the reverse order at different latencies. They found that, overall, two odors presented in one order and vice versa became “perceptually distinct” when the two odors were separated by just 60 milliseconds. within a single smell, Zhou said.
The researchers noted that they only used four odors and that it would be beneficial to test a wider range to see if the human sense of smell is more sensitive to certain odor dynamics or compounds. “This could provide a deeper understanding of the computational principles underlying our olfactory experience,” said Zhou.
The contribution of new discoveries
The new findings challenge previous research in which the time needed to discriminate sequences of odors was about 1,200 milliseconds, wrote Dmitri Rynberg, MD, professor in the Department of Neuroscience and Physiology at NYU Langone Health in New York, in an accompanying editorial. the study in Nature Human Behavior.
“The rhythm of individual notes in music is essential to conveying the meaning and beauty of a melody, and the human ear is very sensitive to this. However, temporal sensitivity is not limited to hearing: our sense of smell can also perceive small temporal changes in odor presentations,” he wrote. “Similar to how timing affects the perception of notes in a melody, the timing of individual components in a complex mixture of odors reaching the nose may be critical to our perception of the olfactory world.”
Source: CNN