Have you ever felt like your dog just understood you? Turns out, you might be more correct than you'd have guessed. For the first time, scientists have compared human brain function to a nonprimate species—and what they found in the study, which researched how dogs process voices, is fairly astounding.
According to research published in the journal Current Biology, the areas of the brain controlling voice interpretation evolved at least 100 million years ago, which is also around the time when humans and dogs diverged from a common evolutionary ancestor. So, that connection you feel with your dog? Humans and dogs have had this connection for tens of thousands of years, thanks to behavioral and neural similarities in their brains.
"Dogs and humans share a similar social environment," says Attila Andics of Hungary's MTA-ELTE Comparative Ethology Research Group. "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."
To study how canine brains responded to dog and human sounds, scientists loaded the dogs into MRI scanners (yes, that is absolutely as cute as it sounds) and then played both types of noises. The researchers then did the same with humans and discovered that the brains of both species responded in similar spots to the sounds. Dogs responded more strongly to other dogs, and humans responded more strongly to other humans—but both species processed the sounds in similar parts of the brain.
Predictably, dogs also proved more responsive to nonvocal sounds, while humans were sensitive to vocal cues.
The most striking similarity appeared in how dogs and humans processed the emotions behind sounds. The primary auditory cortex became more active when subjects heard happy sounds rather than unhappy ones. That aspect was consistent across species.
"This method offers a totally new way of investigating neural processing in dogs," Andics says. "At last we begin to understand how our best friend is looking at us and navigating in our social environment."
We can only assume that cats lack this brain function.