The journal Behavioural Processes published the results of the first brain-imaging study of dogs responding to biological odors. The research was led by Gregory Berns, director of Emory’s Center for Neuropolicy.
“It’s one thing when you come home and your dog sees you and jumps on you and licks you and knows that good things are about to happen,” Berns says. “In our experiment, however, the scent donors were not physically present. That means the canine brain responses were being triggered by something distant in space and time. It shows that dogs’ brains have these mental representations of us that persist when we’re not there.”
When humans smell the perfume or cologne of someone they love, they may have an immediate, emotional reaction that’s not necessarily cognitive, Berns notes. “Our experiment may be showing the same process in dogs. But since dogs are so much more olfactory than humans, their responses would likely be even more powerful than the ones we might have.”
In 2012, Berns led the team that captured the first brain images of alert, unrestrained dogs, using harmless functional magnetic resonance imaging (fMRI), setting the stage for exploring the neural biology and cognitive processes of man’s best friend. He has shown that dogs have a positive response in the caudate region of the brain when given a hand signal indicating they would receive a food treat, as compared to a different hand signal for “no treat.” In humans, the caudate region is associated with decision-making, motivation and processing emotions.
Berns conducted the scent research with Andrew Brooks, also with Emory’s Center for Neuropolicy, and Mark Spivak, owner of Comprehensive Pet Therapy.
“Olfaction is believed to be dogs’ most powerful and perhaps important sense, making it an obvious place to explore canine social cognition,” Spivak says.
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 dog scents were swabbed from the rear/genital area and the human scents were taken from armpits.
“Most of the dog