We know our dogs understand at least some human speech. They get excited when we say walk or leash, and they respond when we use an affectionate tone of voice to speak to them. How the canine brain processes both human words and voice intonation—and how it integrates the two—has remained largely a mystery.
So, how do dogs process what we say to them?
A 2016 study by Attila Andics and colleagues, published in the journal Science, sheds some light on the issue. Andics, an investigator at Eötvös Loránd University in Hungary, decided to test the neural responses of dogs to specific words and variations in tone by human speakers.
Andics used Magnetic Resonance Imaging (MRI) to assess the brain activity of dogs in response to recordings of their trainer’s voice. This itself was no easy task, because the MRI process requires subjects to remain virtually motionless while inside the machine. And since the dogs were not restrained or sedated, the investigators had to find some supremely trained dogs to participate in the study. Fortunately, they did—and the results were fascinating!
The investigators recorded neural responses in the brains of dogs as they listened to recordings of their trainer’s voice saying a series of words they knew, along with some neutral words. As the investigators expected, the dogs’ brains reacted strongly to familiar words. Then they switched things up a bit and had the dogs listen to neutral words spoken in a high-pitched cheerful tone, while known words were said in a neutral, deadpan tone.
The dogs, it turns out, processed the words and the speaker’s tone in different areas of their brains. Words were processed in the left hemisphere of the brain, in much the same way our human language centers process speech. Intonation, on the other hand, was processed in the auditory areas of the right hemisphere. The dogs knew they were being praised even if they didn’t recognize the words being said, and they recognized familiar words regardless of tone, but the reward centers of their brains responded most intensely when familiar words were spoken affectionately.
The science says...
For one thing, the study results show us that dog and human brains share some common characteristics in the way they process communication. Language is processed in the left brain, with emotions (reward, praise, etc.) in the right. The study also suggests that these similarities are not a result of the centuries of domestication, but rather that the ancient neural mechanics of dog brains make them well suited for human companionship.
So, while our dogs may not always do what we tell them, they are truly humans’ best friends.
Cecily Kellogg is a pet lover who definitely has crazy cat lady leanings. Her pets are all shelter rescues, including the dog, who is scared of the cats. She spent eight years working as a Veterinary Technician before becoming a writer. Today she writes all over the web, including here at Figo.