A new study found that like humans, a dog's brain also has a dedicated "voice area' that is sensitive to acoustic cues of emotion.
This finding probably explains why humans share such a close bond with the animal, helping researchers better understand the behavioral and neural mechanisms that made this alliance so effective for tens of thousands of years. The new study, conducted by researchers from MTA-ELTE Comparative Ethology Research Group in Hungary, found that this "voice area" developed more than 100 million years ago when the last common ancestor of humans and dogs existed.
"Dogs and humans share a similar social environment," said Attila Andics of MTA-ELTE Comparative Ethology Research Group in a press statement. "Our findings suggest that they also use similar brain mechanisms to process social information. This may support the successfulness of vocal communication between the two species."
For the study, 11 dogs were trained to lay motionless in an fMRI brain scanner so that a neuroimaging experiment conducted on humans could also be run on the animal. The experiment captured both the species' brain activities while they listened to 200 different human and dog sounds. These sounds included whining, crying, playful barking and laughing.
Findings revealed that both species had their "voice area" in similar locations in their brains. While dogs responded more strongly to dog sounds, human brains were more active when they heard other human sounds. Additionally, researchers noted many similarities in the way both species processed emotion loaded sounds. An area near the primary auditory cortex in the brains of both species lit up more brightly on hearing happy sounds than sad ones.
One difference researchers found was that 48 percent of all sound-sensitive brain regions respond more strongly to sounds other than voices in dogs while the same was true for only 3 percent in humans.
Findings of this study may offers clues in better understanding how well tuned in dogs are to human feelings and why they understand human emotions better than other animals.
"This method offers a totally new way of investigating neural processing in dogs," Andics said. "At last we begin to understand how our best friend is looking at us and navigating in our social environment."
The study titled "Voice-sensitive regions in the dog and human brain are revealed by comparative fMRI" was published in the online journal Current Biology.
