As you read this, take a whiff. What smells do you detect? How do these smells affect how you feel?
It’s rare that people consciously take in the smells around them, but a new review argues that the human sense of smell is more powerful than it’s usually given credit for, and that it plays a bigger role in human health and behavior than many medical experts realize.
“The fact is the sense of smell is just as good in humans as in other mammals, like rodents and dogs,” John McGann, a neuroscientist at Rutgers University-New Brunswick in New Jersey and the author of the new review, said in a statement.
People often think of dogs and rats as the superior sniffers in the animal kingdom, but humans also have an extremely keen sense of smell, McGann argued in the review, which was published last year, May 11 in the journal Science.
In fact, humans can discriminate among 1 trillion different odors, McGann wrote, far more than a commonly cited claim that people can detect only about 10,000 different smells. [10 Things That Make Humans Special]
By overlooking humans’ keen smelling abilities, medicine may be missing a key component of human health, McGann said. S
mell influences human behavior, from stirring up memories to attracting sexual partners to influencing mood to shaping taste, he said.
It’s no coincidence that the French word for smell, “sentir,” also means to feel; emotion and smell are often intricately linked.
Smell and the brain
It’s true that humans have relatively smaller olfactory organs and fewer odor-detecting genes compared with other animals. However, the power of the human brain more than makes up for this.
When a person smells something, odor molecules bind to receptors in the nose.
These receptors send information about the molecules to the human olfactory bulb in the brain, which then sends signals to other areas of the brain to help identify scents.
This is different from the way smell works in dogs, McGann said. Dogs have a “pump” in their noses that’s designed to take in chemicals in liquid form for identification, he said.
Because the smelling mechanisms are so different, it’s hard to compare humans to dogs, McGann said.
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