Smell can be as fast as sight and hearing. STUDY

Smell is a faster sense than previously thought. Humans sense changes in milliseconds of smell as quickly as they might notice a change in color, new research shows.

The study refutes the idea that smell is a “slower” sense than sight or hearing, scientists say.

Smell can be as fast as sight and hearing

The human sense of smell is nowhere near that of many animals, such as dogs. But it may not be as slow as most people think, the new study found.

“A sniff of odors is not a long exposure to the chemical environment that is average” over time, explained the study’s lead author, Dr. Zhou Wen, from the Institute of Psychology of the Chinese Academy of Sciences.

Instead, olfaction can notice fluctuations in odors with a “sensitivity akin to that of color perception” in vision, she said in an academy press release.

The Chinese team built a special odor-triggered device that organized odor emissions with an accuracy of 18 milliseconds. Using the device, they had it produce two odors back-to-back, separated by milliseconds, alternating which odor came first.

They then had 229 people sniff the scents to see if they could smell any difference.

According to the academy’s press release, “participants could tell the difference when the delay between the compounds was just 60 milliseconds—about a third of the time it takes to blink.”

This is roughly equal to the time it takes the human visual sense to distinguish the order of flashing green and red lights, Zhou’s team noted.

Smell can be crucial to the world around us

Dr. Dmitry Rinberg, a professor of neuroscience and physiology at NYU Langone Health in New York City, described the new findings as similar to how people hear music.

“The timing of individual notes in music is essential to conveying meaning and beauty in a song, 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.

“Much like how timing affects the perception of notes in a song, the timing of individual components in a complex mixture of odors reaching the nose may be crucial to our perception of the olfactory world.”

Therapeutic uses

Rinberg believes it is time for the human sense of smell to be taken more seriously by science.

“The study of human olfaction has historically outstripped that of sight and hearing because, as humans, we think of ourselves as visual creatures who use speech to a large extent to communicate,” he said.

His team’s findings are not just a scientific curiosity, Zhou told CNN.

“Our device could be used for therapeutic purposes, such as olfactory training for patients with olfactory loss,” Zhou said.

The findings, published in the journal Nature Human Behaviourcould guide the design and development of electronic noses and olfactory virtual reality systems, which could have significant clinical benefits.