Your dog reacts not just to your words, but also to your tone. If you are a dog lover, you probably knew this much before scientists stepped in to spend weeks studying it. So sometimes, you could tell experts a thing or two about your pet.
Still, this is what they have discovered: that doggy brains can process speech exactly like humans. They react to the tone of voices as well as words.
"We talk to dogs all the time but we know little about what they get from all this. If dog brains also process what we say, then we have to re-think what makes words uniquely human," said Attila Andics, from Eötvös Loránd University in Budapest and author of the study. "Dogs not only tell apart what we say and how we say it, but they can also combine the two, for a correct interpretation of what those words really meant."
Hence, it is not just humans who can understand and comprehend human language. Moreover, scientists also learnt how dogs evolve and develop understanding of language.
For the study, Andics and his colleagues used 13 dogs and trained them to lie totally still with fMRIs strapped to their brains. The experts were able to scan and search what they were going through. The trainers gave them some meaningful words in a neutral or praising tone. Next they switched to garbled and meaningless words in the same kind of neutral or praising tone.
Scientists found that the meaningful words could activate dogs' left hemispheres and got into the action of processing the words. Meaningless words activated their right hemispheres, activating them to understand the tone. By matching words as well as tone, both parts of the brain worked together in order to give and interpret the meaning.
The left part of the human brain also processes language, while the right part struggles to understand intonation. Together, both parts are able to grapple and make sense of language.
"We see now that speech processing mechanisms in dogs and humans are more similar than we thought," Andics said.
The biggest reward trigger in the brains of dogs is the tone and words that praise the dogs.
"Praise is rewarding for dogs, but only if both word meaning and intonation match," Andics said.
However, spelling out words that denote action does not make sense to the dogs. As dogs hear so many parts of speech, such as prepositions and conjunctions that are meaningless, they tend to tune out spelled out words too.
The research report, "Neural Mechanisms for Lexical Processing in Dogs," will appear in Science.
