Gaby
Humans can recognize a scent in just 0.06 seconds. That’s about a third of the time it takes to blink and nearly as long as it takes to identify a color.
Previously, researchers thought smell recognition was relatively slow because it seemed tied to our breathing. A full inhale and exhale takes about three to five seconds.
A new study found we can detect subtle chemical changes in odors even faster than a single breath.
How Was the Study Conducted?
A team at the Institute of Psychology at the Chinese Academy of Sciences built a device that delivered measured doses of scent, triggered by a participant’s sniff. During the study, the device presented aromas such as apple, onion, lemon, and flowers to volunteers’ noses.
In total, 229 volunteers participated in the study. The researchers wanted to find out how quickly participants could distinguish between two different scents presented at precisely measured intervals and in varying orders.
The team found that when two scents were presented back-to-back, volunteers could tell them apart in just 0.06 seconds—about ten times faster than researchers had expected.
The experiment also confirmed that the stronger the concentration of a scent, the quicker our noses can identify it.
Dr. Wen Zhou, a co-author of the study, said inhaling scents isn’t like a “long-exposure photograph” that averages different smells; it’s a process that’s sensitive to change.
In their report, the researchers wrote, “Our results showed that human olfactory perception is sensitive to chemical dynamics within a single breath and provided behavioral evidence for the temporal coding of odor identity.”
The findings were published in the journal Nature Human Behaviour.
Another Study on Scents
In a separate study, researchers at the University of Erlangen-Nuremberg in Germany compared the chemical composition of scent samples from 18 infants (from days old to three years) and 18 teenagers (ages 14 to 18).
They found that teenagers’ scent was a mix of sweat, urine, musk, and sandalwood, while infant samples were described as smelling like “violet” and “soap and perfume.”
