Dogs should be afforded the same rights as humans in the eyes of the law, a leading neuroscientist has said.
Gregory Berns, professor of neuroeconomics at Emory University writing for the New York Times, said he has spent the last two years studying canine MRI scans and has reached the conclusion that "dogs are people too".
Berns trained dogs to go into an MRI scanner awake and unrestrained. Normally, to take brain scans, dogs are placed under anaesthetic as movement disrupts the picture, but this means functions such as perception and emotion cannot be studied.
"It has been easy to sidestep the difficult questions about animal sentience and emotions because they have been unanswerable," he wrote. "By looking directly at their brains and bypassing the constraints of behaviourism, MRIs can tell us about dogs' internal states."
Berns said he trained dogs to go into the MRI scanner and if they did not like it, they were free to leave. One of the first dogs to be scanned was his own dog, Callie.
"After months of training and some trial-and-error at the real MRI scanner, we were rewarded with the first maps of brain activity. For our first tests, we measured Callie's brain response to two hand signals in the scanner.
"In later experiments, not yet published, we determined which parts of her brain distinguished the scents of familiar and unfamiliar dogs and humans.
"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."
Indication of canine emotions
In humans, the caudate is involved in the anticipation of things we enjoy, such as food, love and money. Berns said caudate activation is so consistent it can predict preferences for food and music.
Findings showed activity in the caudate of dog brains increased to smells of familiar humans and the anticipation of food.
"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."
Berns said dogs should not be considered as property that can be disposed of, and laws should be put in place to protect animals' interests.
"If we went a step further and granted dogs rights of personhood, they would be afforded additional protection against exploitation. Puppy mills, laboratory dogs and dog racing would be banned for violating the basic right of self-determination of a person."
He accepted that it will be many years before dogs are considered humans, but noted that recent court rulings that used neuroscience to show youth offenders' brains were not fully developed shows a willingness to look at scientific evidence.
"Perhaps someday we may see a case arguing for a dog's rights based on brain-imaging findings," he concluded.