The next time you want to praise your dog, use a positive word or phrase it knows—  and say it in a praising way. That’s the finding of new research that reveals that both words and tone matter when humans communicate with canines.

Researchers studied 13 trained dogs in Hungary. The canines were analyzed under a functional MRI machine, which looked at blood flow in their brains. A recording played different words, spoken by their trainer with different tones. That means that the dogs heard praise words said in a praising tone, praise words said in a neutral tone, neutral words said in praising way, and neutral words spoken with a neutral tone.

The scientists discovered that it was the praising words said in a positive way that showed a reward in the dog’s brain. In other words, saying a word that means nothing— but doing it in a praising tone— wouldn't register the same way a meaningful word said in a praising way would, according to the research.

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“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. 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,” Attila Andics, the first author of the study and a neuroscientist at Eötvös Loránd University, said in a statement.

The dogs used the left hemisphere of their brain to process the words they knew, and the right to process intonation, like humans, according to the study, which was published in the journal Science.

The study also points out that dogs have the ability to recognize as many as about 1000 words, when told to fetch objects.

So while dogs probably won’t be listening attentively to full sentences anytime soon, the new research shows that words and tone matter, and that when they match, the dogs notice.

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