Our Sniffers Are Nothing to Sneeze at

It takes 180 milliseconds to blink but as little as 60 for the human nose to discern sequences of odors within a single sniff. That finding, emerging from a study published Monday in the journal Nature Human Behaviour, suggests humans, whose sense of smell is often considered weak, "are as sensitive to rapid changes in odors as we are to rapid changes in color," the Guardian reports. Researchers hooked up two bottles of scents to a nose piece using different lengths of tubing, fitted with valves that opened when a participant inhaled. The result was that one scent would arrive to the nose milliseconds before the other. Some 229 adults in China were then asked to take a sniff and report what order of smells arrived.

When the smells were delivered 120 to 180 milliseconds apart, participants gave the correct order 63% of the time. And when the smells were delivered 40 to 80 milliseconds apart, the best-performing participants could give the correct answer at a rate better than chance. That's a big deal since previous research indicated it took 1.2 seconds, or 1,200 milliseconds, to distinguish between odor sequences, experts write in an accompanying editorial. The new study shows this can be accomplished in a tenth of that time.

This level of sensitivity is "on par" with how our brains perceive color, "refuting the widely held belief that olfaction is our slow sense," the study reads, per CNN. Study author Dr. Wen Zhou, an investigator at the Chinese Academy of Sciences, says researchers were "astonished" by the results. "The demonstration that humans can tell apart smells as they change within a sniff is a powerful demonstration that timing is important for smell across species, and therefore is a general principle underlying olfactory function," Harvard neurobiology professor Dr. Sandeep Robert Datta, who was not involved in the study, tells CNN. Zhou says the findings "could guide the design and development of electronic noses and olfactory virtual reality systems, which could have significant clinical benefits." (More sense of smell stories.)