Similar “voice areas” Found in Both Dog and Human Brains

Scientists have for the first time compared brain function between humans and dogs and found similarities in how they respond to voices. Strikingly, like in humans, these regions in dog brains are modulated by the emotion of the voice.

The researchers trained 11 dogs to lie still in an fMRI brain scanner. The dogs (and some humans) listened to a range of human and dog sounds varying in emotion, ranging from whining and crying to playful barking and laughing. fMRI measures the amount of oxygenated blood flowing to a region of the brain; the more oxygenated blood, the more active that brain region is. It turns out that similar brain regions were active in both the dogs and humans when listening to voices. Each species responded most strongly to their own species’ voice, dogs brains ‘lighting up’ more for barks than human voices.

Interestingly, the species responded to emotional sounds in similar ways, with an area near the primary auditory cortex (where sound information is first processed) showing significantly more activity when unhappy sounds were played.

This finding could explain how dogs can respond to human vocal commands so easily and the strong bond between man and dog. The finding is not that surprising considering that over the 18-32 thousand years of domestication humans dogs have had very similar social environments, so social brain mechanisms (like communication) could have developed similarly.

But we aren’t exactly the same as dogs: in dogs 48% of sound-sensitive regions responded more to sounds that were not voices, whereas this is only 3% in humans, probably reflecting our greater reliance on vocal communication and the importance of hearing voices for humans. Nevertheless, this study gives some insight into how dog became man’s best friend.