Dogs distinguish words and intonation in the same region of the brain as humans, according to a new study of how man's best friend interprets our language.
Published Monday in the journal Science, the report by researchers at Budapest's Eotvos Lorand University shows the canine brain is capable of interpreting both what we say and how we say it.
Dogs, like humans, use the brain's left hemisphere to interpret words and regions of the right hemisphere to analyze intonation.
The brain's pleasure center is activated only when words of kindness and praise are accompanied by the appropriate intonation, the researchers determined.
The observations suggest that the neural mechanisms for processing words evolved much earlier than previously believed and that they are not unique to the human brain.
In surroundings with many spoken words such as a family home, understanding of word meanings can develop even in the brains of animals unable to speak, the study shows.
"The human brain not only separately analyzes what we say and how we say it, but also integrates the two types of information, to arrive at a unified meaning," says Attila Andics, a research fellow at Eotvos Lorand University.
"Our findings suggest that dogs can also do all that, and they use very similar brain mechanisms," a discovery that could help facilitate communication and cooperation between dogs and humans.
The scientists studied thirteen dogs who remained lying still while a brain scanner measured their brain activity as they listened to their owners speak.
They found the dogs would activate an area of the right brain to distinguish between intonation signaling kindness and neutral tones. The researchers had already identified that the same part of dogs' brains interprets non-verbal sounds that elicit emotions.
The same area of the human brain plays a similar role, suggesting that the mechanisms for interpreting intonation aren't specific to speech.
"What makes words uniquely human is not a special neural capacity, but our invention of using them," the scientists said.