How Well Can You Smell?

Dec. 18, 2006— -- Imagine yourself blindfolded and wearing earplugs: Could you follow a chocolate scent with only your nose to guide you?

Surprisingly, most of us can, according to a new study published in Nature Neuroscience this week.

Watch "Good Morning America" Monday at 7 a.m. ET for more on this story.

Researchers put blindfolds, earplugs and gloves on human volunteers, and asked them to find a chocolate scent trail on the ground and track it to the end like a dog would. Researchers found that volunteers could use some of the same smell techniques animals use to follow scent trails.

"We wanted to look at not only if humans could track scent, but how they are able track scent," said Jessica Porter, lead author and a Ph.D. candidate in biophysics at the University of California at Berkeley.

"'Strawberryness' or 'mintyness' relies on the nose, not the tongue," said Dr. Jay Gottfried, assistant professor of neurology at Northwestern University in Chicago. "Humans rely on smell much more than they appreciate."

"The reason humans have the impression that our smell isn't as good as other animals' is that we use it in such a limited way," said Dr. Gordon Shepherd, professor of neuroscience at Yale University.

People born without the ability to smell highlight the importance of this neglected sensory ability.

"Patients without the ability to smell do suffer a lot. They usually don't know there is a problem until they are kids -- and when others smell that apple pie, but these kids can't," said Gottfried.

"These people without the ability to smell have to ask family members if the milk is spoiled. And they usually cake on cologne or perfume because they are worried they may not be able to detect their own body odor."

Many animals -- especially dogs -- are known for their keen sense of smell. So how do humans stack up against our canine companions?

"It depends a lot on specifically what you want to compare," said Porter. While dogs can detect many odors at much lower concentrations than humans, "there are examples where humans are actually better. It is not necessarily that the human sense of smell is worse than that of other animals, it is just different."