People Can Learn To Use Their Sense Of Smell Like A Dog Does : Shots - Health News We humans think we don't have a very good sense of smell. But psychologist Alexandra Horowitz says dogs can show us how to train our noses so they give us a window into a secret world.
NPR logo Learn To Sniff Like A Dog And Experience The World In A New Way

Learn To Sniff Like A Dog And Experience The World In A New Way

Researcher Alexandra Horowitz plays with her dogs Finnegan and Upton. She studies how dog's sense of smell influences their view of the world. Vegar Abelsnes/ Courtesy of Alexandra Horowitz hide caption

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Vegar Abelsnes/ Courtesy of Alexandra Horowitz

Researcher Alexandra Horowitz plays with her dogs Finnegan and Upton. She studies how dog's sense of smell influences their view of the world.

Vegar Abelsnes/ Courtesy of Alexandra Horowitz

This week the podcast and show Invisibilia examines the nature of reality, with a Silicon Valley techie who created apps to randomize his life; a wildlife biologist who thinks bears aren't dangerous; and a psychologist who trains herself to experience the world like dogs do.

Noses are the unsung feature of the face, sunscreened or surgically fixed, but rarely exalted. And the sense they enable, smelling, is likewise uncelebrated. Regularly voted the "sense I'd be most willing to lose", olfaction is largely ignored — unless it brings word of something savory or foul nearby.

But we are born smellers. After being enveloped while in the womb in the smell of our mother and the foods she ingested, babies emerge macrosmatic, keen-smelling. They find the mother's nipple and recognize their parents by scent. Children can identify their siblings and friends by smell. In those earliest sniffings, smelling is all about discovery and navigation.

Gradually, though, we forsake our noses. What have you smelled today? Perhaps a half-dozen odors, mostly likely food or manufactured fragrance, or maybe one. Or none. Over the same period, your dog has sniffed his way out of sleep, come to examine your smell in the morning, busily investigated the smell leavings from the night before on your walk outside, and may have found his way to his fellow canines by scent.

Reality Check

What happens when people can't agree on reality? Alix Spiegel and co-host Hanna Rosin examine how two people can look at the same thing and experience two different emotions in the second episode of Season 3 of the NPR podcast Invisibilia.

We admire the dog's olfactory acuity, and we should: dogs have hundreds of millions more olfactory receptors, the cells at the back of the nose that grab odors out of the air, than we do. They have two dedicated, separate routes in their snouts for sniffing and breathing; they have elaborate bones in their nose that hold yet more olfactory tissue; they even exhale out the side slits of their nostrils in order not to disturb the odors coming in. And as the performance of dogs that do tracking, search-and-rescue, and other detection tasks, they can use their highly sensitive olfactory instruments to locate substances that we never even thought had an odor: cancerous cells; minute quantities of TNT; the day-old footprint left by a missing person.

All is not lost for us humans, though. We have the equipment, and, while not as varied or extensive as the dogs', it works perfectly well. Last month John McGann, an Associate Professor at Rutgers, published a review in Science last month reminding us that humans do, after all, have an olfactory bulb, and Swedish professor Matthias Laska has extensively demonstrated that in detecting some odors, such as amyl acetate (which smells like banana), we are plenty sensitive. Our experience of the flavor of food is mostly due to smell, experienced through the back of the mouth — retronasal olfaction — instead of through the nostrils.

Knowing all this, I recently embarked on a project culminating in my book Being a Dog: Following the Dog into a World of Smell, in which I tried to improve my sense of smell by following the dog's lead, as well as that of some olfactory experts, among them a perfumer, a sommelier, and a pair of animal trackers. Dogs excepted, few of these experts were born noses. I learned that a few simple steps can change your nose from neglected to noticed, as it had for them:

Stick your nose in it. Consider a dog's daily behavior, and contrast it with the frequency with which you see a person with nose smashed against a surface, inhaling calmly and confidently. Simply getting closer to a source and bravely sniffing will bring more odor molecules into our noses.

Get over it. In the U.S., at least, our culture is a discourager of smells. The baby who notices an interesting smell? Her parents ignore her. Eventually, she will think of smells in a mostly binary way, as lovely or horrible. By contrast, experts in smelling view odors merely as information, not intrinsically good or bad, just as the images that we see tell us about our world. Treat scents like sights and it becomes easier to smell.

Name the source. Once you start bringing your attention to what you smell, you may be at a loss for words: English doesn't have much of a vocabulary for smells. So olfactory experts create their own jargon. You can adopt theirs, but consider, too, our smell memories: The scent of cedar mixed with tobacco that floods me with memories of my father's desk; a whiff of pencil shavings, zipping me back to learning cursive in my third grade classroom. Find your own language, images or memories to represent the smell, and in so doing it will be easier to invoke the next time you sniff it.

Even after spending months learning how to smell like a dog, observing detection dog training, following truffle dogs, and accompanying my own dog train in the sport of "nose work", I feel certain: I don't experience the world my dog does. But my own world is changed: It smells. And by smelling intentionally instead of just letting smells happen to me, odors have lost their simplicity.

I'm glad to smell my family and friends. I know the smell of the afternoon in my office, warmed by sun, as well as the smell of the advent of spring. Before opening my eyes on awakening this morning, I could smell that the dogs and cat had joined me in bed, but my husband was up. In the next hour, I smelled mown grass and a waft of cloves in the park; the mustiness of a raincoat taken out of a back closet; when the toast was ready; and the beautiful, straw-like smell of the top of my son's head. I relish it all.

Alexandra Horowitz is head of the Dog Cognition Lab at Barnard College and author of the recent book Being a Dog: Following the Dog into a World of Smell.