You’ve probably heard the common wisdom that it doesn’t really matter what you say to your dog, as long as you say it in a nice way.
Maybe you found this distressing, since you like to believe your pup knows exactly what you mean when you tell him “I love you” 12 to 14 times per day.
But it turns out dogs may understand more than humans have traditionally given them credit for, according to a new study by researchers at Eötvös Loránd University in Budapest, Hungary, published in the journal Science this week.
Researchers recruited 13 family dogs living with their human owners, and trained the dogs to sit in an fMRI scanner — a device that measures brain activity — while awake. Lead researcher Attila Andics and his colleagues note that the dogs — a group mostly made up of border collies and golden retrievers — were never restrained inside the scanner and were free to leave if they chose.
The scientists recorded a trainer’s voice saying certain phrases with varying types of intonation.
In one recording, she said Hungarian expressions “used by all test dog owners for praising” with the same type of vocal intonation a person would typically use to praise a dog. She also spoke a variety of “neutral” words — like conjunctions that are unlikely to carry any particular meaning — and said them in a neutral tone of voice.
However, the trainer also switched up these combinations — saying the “praise” phrases in a neutral tone of voice, and saying the “neutral” phrases in a tone that sounded like she was praising the dogs.
Then, researchers monitored each dog’s brain waves while they played various phrases.
They found that the dogs processed the words and tone of voice separately, in different sections of the brain. When they heard the familiar “praise” words, the left hemisphere of their brains lit up — the same general location that humans use to process language. This occurred no matter what tone the trainer was using.
The dogs appeared to register tone, however, in their right hemisphere. Again, this is in the same place that people do it.
Although the dogs appeared to be processing the familiar words regardless of tone, that didn’t mean that tone was insignificant.
The dogs’ “rewards center” — where they process things like positive attention and foods — was stimulated when they heard the praise words spoken in a positive tone. In other words, they processed the praise words as familiar no matter how they were spoken, but it only registered as positive attention when they were spoken in a praising tone.
“It shows that for dogs, a nice praise can very well work as a reward, but it works best if both words and intonation match,” Andics, the lead researcher, said in a statement. “So 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. Again, this is very similar to what human brains do.”
The results don’t necessarily prove that dogs can grasp the precise meaning of all familiar words, but it does indicate that they can distinguish between words they’ve heard before and words they haven’t. And it suggests that they at least associate familiar “praise” words with positive outcomes.
“One important thing is that we don’t claim that dogs understand everything we say, of course,” Andics told The Huffington Post in an email.
Dog owners have known for a long time that they could use verbal commands to train their dogs and communicate with them, like telling a dog to “sit.” But Andics explained that even dogs’ reactions to those commands are often hard to separate from the tone of voice and body language that a trainer might incorporate. His study indicates that dogs can recognize familiar words, independent of context like tone of voice and body language.
“The main result is not that they can differentiate words, but that they differentiate meaningful and meaningless words, and the left hemisphere has a key role there,” he said.
He added that he suspects researchers would find similar results with other domestic animals like cats and horses, if the animals in question had lived among humans.