What’s Your Dog Really Thinking? Science Is One Step Closer to the Answer
It’s the million-dollar question for anyone who owns a pet: What’s your dog really thinking?
Thanks to a feat never before performed by scientists, a team of researchers at Emory University has completed the first in a planned series of experiments to dive deeper into canine gray matter — and the relationship between humans and their pets.
How’d they do it? By wiring two dogs to a functional Magnetic Resonance Imaging (fMRI) machine, the same type used to map the workings of the human brain.
“This experiment was a proof of concept,” says Dr. Gregory Berns, M.D., Ph.D., director of the Center for Neuropolicy at Emory University, who led the experiment. “Nobody had ever accomplished doing an MRI, or even a functional MRI, on a completely awake, unrestrained dog.”
He’s quick to point out that no animals were harmed in the process of the experiment. In fact, one of the two dogs tested, Callie, a Feist hunting dog he adopted from a shelter, was his own.
Vetstreet sat down with Dr. Berns to pick his brain about what he learned about dogs’ wiring — and where research on the human-dog bond is headed.
You’ve come one step closer to answering the question: What is a dog thinking while looking at his owner? Why didn’t anyone try this sooner?
A. Dr. Berns: "The reason no one ever attempted this before is that everyone previously thought the dog was going to move too much [in the machine]. We hit on the idea that that’s not necessarily true, so let’s see if we can train some dogs to hold their heads perfectly still to get perfectly fine MRI images.
Then, once we were sure we could get that, we started asking reasonable scientific questions that were really simple. We used two hand signals — one indicated to the dog that he was going to get a hot dog treat, the other was to get no treat."
What did you expect to find in terms of brain activity?
A. "We already know a great deal about how the reward system of humans works, which is pretty much how it works in all animals. We knew it should be located in the brain, and we wanted to work out the details of how it does work — and quiet the critics who say that you can’t make a dog do that. We’re now at a stage where we can ask more complicated questions about the dog-human relationship."
What was the hardest part about working with dogs?
A. "It’s not so much getting them in the scanner. That builds on natural behaviors — it’s easy to teach them to walk up steps and into a tube. Even placing their heads in a chinrest is a natural position for a dog.
The most difficult part is the noise. MRIs are 95–100 decibels loud, and the dogs are obviously much more sensitive to sounds than we are . . . and it’s bad enough for humans. We trained them to wear earmuffs, and a lot of dogs don’t like messing with their ears. I would [also] play background noises on the stereo that mimicked the machine.
It’s probably the thing that I’m most proud of in the experiment: The amount of care and thought that we’ve given to the dogs. We essentially treated them like humans. If they don’t like the experiment, they just get up and walk out. As far as I know, that’s a first."
How did the mission to capture Osama Bin Laden inspire you?
A. "I hadn’t thought about doing this until I saw all those pictures of dogs jumping out of helicopters [involved in the rescue]. Nobody thought to do this, because, historically, people who have done MRIs on dog brains are vets. If you take your dog into an MRI, they’re anesthetized. I don’t think that anyone thought to train dogs to do this. But, in retrospect, they’re great. They’re very easy to train, and it’s fun for all of us."
When Callie saw the hand signal for a hot dog treat, the caudate part of the brain lit up, which is the same area of the human brain that becomes active when something good is about to happen. Did this surprise you?
A. "When we measure the fMRI, we’re measuring changes in blood flow to the area, and there are really only three animals in which the reward system has been studied in-depth: humans, rats and monkeys. And so everything that we know about the reward system seems to be the same in all of the species. We had no reason to believe it would be any different in dogs."
What role did dopamine — the “reward” neurotransmitter in our brains — play?
A. "Well, the thing is, it’s not merely a pleasure neurotransmitter. It has more to do with an expectation of something positive, and it acts to orient the animal or the person toward an action that they think is going to be good. I call it the 'fuel injector behavior' because, when it activates, gears change in the brain."
So when I tell my dog that we’re going outside or ask him if he wants cheese, is that what’s happening?
A. "At those points in time, when you’re doing the asking, those things are not expected to him, and it releases dopamine. He thinks, 'I know she said something important, so I better pay attention.' It’s not happening at the moment that he gets outside or gets to eat the cheese."
What do you hope to discover in the future?
A. "The fact that it worked was surprising enough — just the ability to see the images of the brains up on the screen. They walked in, they put their heads down, and we got the pictures. But now we have more questions: All of them are geared at understanding what a dog is perceiving about humans.
We want to look at whether they consider humans part of the pack. Do they differentiate between humans and other dogs? Are we what anthropologists would call 'fictive kin' . . . do dogs lump us all together? Ultimately, I would like to know if dogs have some form of self-awareness, and do they have some capacity for love. We’ve got years of experiments in the plans."
To see how Dr. Berns trained the dogs to enter the fMRI machines, watch this video.