Dogs and Humans Have Similar Brain Response to Voice and Noise

Researchers have compared the human brain with the brain of dogs, finding that both man and man's best friend have cerebral areas dedicated to dealing with voice and acoustic emotional cues. The finding may be biological evidence between the successful communication ability between humans and canines.

Writing in the journal Cell Press, the researchers suggest that cerebral voice areas evolved at least 100 million years ago with the last common ancestor of humans and dogs.

The study was the reportedly the first to compare brain function between humans and any non-primate animal.

"Dogs and humans share a similar social environment," said lead study author Attila Andics of the MTA-ELTE Comparative Ethology Research Group in Hungary. "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 conduct the research, Andics and her collaborators trained 11 dogs to lay motionless in an fMRI brain scanner, allowing them to take a clear image of the dogs' brains.

They recorded both humans' and dogs' brain activities while the subjects listened to nearly 200 dog and human sounds ranging from playful barking and laughing to whining or crying.

"The images show that dog and human brains include voice areas in similar locations," the researchers said in a statement. "Not surprisingly, the voice area of dogs responds more strongly to other dogs while that of humans responds more strongly to other humans."

Andics said it was most surprising to find such a common response to emotion across species. In both dogs and humans, an area near the primary auditory cortex lit up more upon on the occasion of happy sounds than unhappy ones, the researchers said.

One striking dissimilarity of dog's and human's aural processing is that for dogs, the sound of non-voice noises registered much more frequently than for humans.

For dogs, 48 percent of sound-sensitive brain regions responded more strongly to non-voice noises, compared to just 3 percent in humans.

"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."