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Modern dog science and a sentimental sniff

Years ago, returning from a hike with my dog Sage, she walked up to a rake my neighbor Mike had dropped off in the yard while we were gone. She sniffed the handle where his hands had held it, and began to wag her tail. I thought it was adorable. She’s thinking of Mike, I figured, and how much she likes him.

Cody with pup

A trainer friend of mine agreed, comparing a dog chewing our socks to a person who sentimentally fondles a snapshot of a loved one. (Remember that next time your best loafers are shredded.)

Well, a terrific new brain-imaging study from Emory University in Atlanta seems to confirm those impressions (and those of, by my estimate, about a million other dog lovers): that a dog can smell the scent of someone they like or love and conjure a happy image of them.

Some scientists, however, might scale back my wording to say the experiment shows that the scent of a familiar person causes a positive reaction in the area of a dog’s brain associated with pleasure.

So what is the study?

Led by Gregory Berns, it’s one more in a series of (humane) experiments being conducted on dogs who have been trained to stay still without restraint while having their brains scanned by a functional magnetic resonance imaging or fMRI.

This one, according to Science Daily, worked like this:

The experiment involved 12 dogs of various breeds. The animals had all undergone training to hold perfectly still while undergoing an fMRI scan. As they were being scanned, the subjects were presented with five different scents that had been collected on sterile gauze pads that morning and sealed in Mylar envelopes. The scent samples came from the subject itself, a dog the subject had never met, a dog that lived in the subject’s household, a human the dog had never met, and a human that lived in the subject’s household.

The scent of the familiar human got the most reaction in the reward center of the brain, the caudate nucleus.

As Science Daily says:

“The stronger caudate activation suggested that not only did the dogs discriminate the familiar human scent from the others, they had a positive association with it,” Berns says. “While we might expect that dogs should be highly tuned to the smell of other dogs, it seems that the ‘reward response’ is reserved for their humans. Whether this is based on food, play, innate genetic predisposition or something else remains an area for future investigation.”

These scientists are studying areas of the brain that seem similar in humans and dogs and watching them on scans to try to understand what dogs are thinking. I love what Berns is doing and I love his common sense and his inkling about canine emotion.

In National Geographic online, he was quoted by Liz Langley as saying:

“To the critics out there, it’s always difficult to prove that an animal is feeling something like a human emotion—although I think they do.”

–Vicki Croke

3 Responses to “Modern dog science and a sentimental sniff”

  1. Catherine Murphy

    Well, no doubt about this. My dogs smell my sister’s scent on the sidewalk and stairs before going into the house. It signals me that she’s in the house too. Tails-a-wagging and gleefulness evolves until I open the door and they see their favorite Aunt. (and on a side note you can say “Auntie is coming over” and they starting wagging their tails like crazy and looking at the front door).

    So cute.

  2. Sally D

    Interesting findings, but I think no surprise to dog owners!
    I had been separated from my dog for 10 weeks. When I returned home, he spotted me from a distance and responded as he would to any new person coming to visit, I’d have to call it “happy anticipation.” But when he got wind of me, literally, he did the closest thing to a human double take that you could imagine, and then he was lost in a whirlwind of excitement and doggy joy. Dogs are VERY good at hellos, and even better at OMG, I thought I’d never see you again.

  3. Haley

    If I send my sock to my sister will her new dog recognize my scent when I visit them?

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