NEW YORK, NEW YORK, October 5, 2013 (by Prof. Gregory Berns for the New York Times): For the past two years, my colleagues and I have been training dogs to go in an M.R.I. scanner -- completely awake and unrestrained. Our goal has been to determine how dogs' brains work and, even more important, what they think of us humans. Now, after training and scanning a dozen dogs, my one inescapable conclusion is this: dogs are people, too.
Because dogs can't speak, scientists have relied on behavioral observations to infer what dogs are thinking It has been easy to sidestep the difficult questions about animal sentience and emotions because they have been unanswerable. Until now.
By looking directly at their brains and bypassing the constraints of behaviorism, M.R.I.'s can tell us about dogs' internal states. My dog Callie was the first. With the help of my friend Mark Spivak, a dog trainer, we started teaching Callie to go into an M.R.I. simulator Soon, the local dog community learned of our quest to determine what dogs are thinking. Within a year, we had assembled a team of a dozen dogs who were all "M.R.I.-certified."
Although we are just beginning to answer basic questions about the canine brain, we cannot ignore the striking similarity between dogs and humans in both the structure and function of a key brain region: the caudate nucleus. Rich in dopamine receptors, the caudate sits between the brainstem and the cortex. In humans, the caudate plays a key role in the anticipation of things we enjoy, like food, love and money.
In dogs, we found that activity in the caudate increased in response to hand signals indicating food. The caudate also activated to the smells of familiar humans. And in preliminary tests, it activated to the return of an owner who had momentarily stepped out of view. Do these findings prove that dogs love us? Not quite. But many of the same things that activate the human caudate, which are associated with positive emotions, also activate the dog caudate. Neuroscientists call this a functional homology, and it may be an indication of canine emotions. The ability to experience positive emotions, like love and attachment, would mean that dogs have a level of sentience comparable to that of a human child. And this ability suggests a rethinking of how we treat dogs. Perhaps someday we may see a case arguing for a dog's rights based on brain-imaging findings.
Gregory Berns is a professor of neuroeconomics at Emory University and the author of "How Dogs Love Us: A Neuroscientist and His Adopted Dog Decode the Canine Brain."