The next time you're talking to your dog, remember that it might pick up more of your intended meaning than you give it credit for.
A new study by researchers in Hungary suggests that dogs can understand both the words we say and the way we say them to a certain degree, using the same parts of the brain as humans do to recognise spoken language.
"During speech processing, there is a well-known distribution of labour in the human brain," lead researcher Attila Andics from Eötvös Loránd University, Budapest told the press this week. "It is mainly the left hemisphere's job to process word meaning, and the right hemisphere's job to process intonation."
When Andics' team measured dogs' brain activity using an fMRI brain scanner, they found evidence of the same kind of cognitive division taking place in canines listening to their trainers' speech.
"The human brain not only separately analyses what we say and how we say it, but also integrates the two types of information, to arrive at a unified meaning," Andics said. "Our findings suggest that dogs can also do all that, and they use very similar brain mechanisms."
During the experiment, 13 dogs listened to recordings of their trainers' voices as they spoke to the animals using different combinations of vocabulary and intonation, speaking both praise and neutral language.
Sometimes the speech the dogs heard was praise spoken in neutral way, or praise spoken with a matching intonation. They also heard neutral language delivered with a praising intonation, and neutral words spoken in a neutral voice.
But regardless of how the trainers delivered praise, the dogs' brain activity suggested that they were actually able to recognise the words as praise, meaning dogs can process vocabulary independently of how it's said, recognising particular words as distinct.
According to the researchers, the brain activity shows that they do this in a similar way to humans, using the left hemisphere to process the meaning of words, and separately processing intonation in the right hemisphere.
Interestingly, while these processes are distinct, the team found that praise only activates the canine brain's reward centre if it is spoken in a praising way.
In other words, just as people wouldn't want to hear complimentary language said to them in a less-than-complimentary way, the same is true for dogs – meaning if you want your dog to feel its happiest, you have to speak praise with praising intonation.
If you don't, it may as well fall on deaf ears, and that would be a tragedy, because interpreting praise is a big deal for dogs. Recent research has found that canines enjoy praise even more than receiving treats – and let's face it, dogs love receiving treats.
"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," said Andics. "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."
It's worth pointing out that only a small number of dogs participated in the experiments, so it will be interesting to see whether larger studies involving a greater number of animals can replicate these results.
If that's the case, the findings suggest that we share more with animals than we thought when it comes to language processing. Of course, humans' mastery of language still makes us pretty unique in terms of the animal kingdom – but it looks like parts of the cognitive activity that make up that mastery could be more common than we previously thought.
"Lateralised lexical processing does not appear to be a uniquely human capacity that follows from the emergence of language, but rather a more ancient function that can be exploited to link arbitrary sound sequences to meanings," the authors explain in Science.
"What makes lexical items uniquely human is thus not the neural capacity to process them, but the invention of using them."
The upshot for you and me: don't be lazy, indifferent, or mumbly when praising your four-legged friend. If you really want your praise to be heard, say it with feeling, guys.