Dogs really can understand what we’re saying to them, according to a new study that seems to confirm the dearest wish of many a dog-lover. And yes, that does mean if you say a mean thing to a dog in a friendly tone, the dog knows.
Researchers led by Attila Andics at Hungary’s Eötvös Loránd University put dogs in fMRI scanners after training them to sit still, according to a study published today in Science. The scientists recorded how the dogs’ brains reacted to hearing their trainer say different combinations of human words in different tones. The finding should cheer up anyone who regularly tells their Pekingese about their day: dogs can recognize the meaning of different words and intonations. And their brains do so in a way similar to how our human brains process language.
The researchers recruited 13 dogs of varying breeds (border collies, golden retrievers, a German shepherd) from one to 12 years old. They played the dogs recordings of their trainer talking to them in different combinations of positive and neutral words and tones. For example, in one recording the trainer might use positive words like "well done!" with a positive, or higher-pitched tone. In another, she might use neutral conjunction words like "if" and "yet" with a positive tone.
The scan results showed that dogs, like humans, process vocabulary and tone with different sides of the brains and then combine the information to find meaning. In humans, the left hemisphere holds Broca’s area, which is heavily used for understanding language. Dogs, too, use the left side of their brain to process vocabulary, and recognize each word as distinct. They also process tone separately in the right side of the brain, just like us.
Most importantly, dogs are smart enough not to be tricked by gibberish said in a happy voice. They can put vocabulary and tone together, and the reward areas of their brains are most active when they hear both positive words and positive tones. One reward area didn’t activate at all if positive words and positive tones weren’t used. A different area activated just a tiny bit when they heard positive words with neutral tone, and all neutral tones. But even that area didn’t respond when there were neutral words with a positive tone, so saying "wow, you messed up again" in the world’s sweetest voice isn’t fooling anyone.
Aside from this being heartening news for man’s best friend, the study authors think the finding has some relevance for us bipeds, too. Domestication might have helped dogs learn to process language in both parts of the brain, but it’s unlikely that it’s the sole reason behind it, they say. This suggests that maybe it wasn’t human language that made our brains process speech with both sides. Rather, it might be that many animals — including humans and dogs — use the same areas to process language.