Dogs understand tone and inflection of human voice
New study finds that dogs understand what we say by our tone & inflection


According to a recent report in the journal Science, when we praise our dogs they’re not just listening to the words we say but how we say them. That’s not really that groundbreaking, because most of us kind of already figured that. Animals know when you’re angry or happy beyond the mere words you utter. Our facial expressions, body language and tone of voice are pretty much dead giveaway s as to how we’re feeling. What is new is that scientists have used imaging to look inside the brains of 13 canines as they listened to the voices of their trainer, and the reward pathway in the animals’ brains lit up like Christmas trees when they heard words of praise accompanied by an approving intonation.  

His Master’s Voice

On the flip side, the same imaging did not note a change when the dogs heard random words stated in a praising tone or words of praise spoken in a flat or monotone. "Dogs process both what we say and how we say it in a way which is amazingly similar to how human brains do," said Attila Andics, a neuroscientist at Eotvos Lorand University in Hungary. He went on to explain that when dogs hear speech they appear to separate the meaning of words from the intonation, leaving each aspect of speech to be analyzed independently. Interestingly, the left hemisphere of the brain processes meaning, while tone or intonation is analyzed in the right.

Understanding Human Language

The animals involved in the study were all volunteers partaking in the experiment without drugs or sedation. They were fully awake and willing participants in every sense of the word. Training included the canines being taught to lie still in the scanner using a training method developed by Marta Gacsi. They could get up and leave the scanner whenever they wished, but it was apparently clear to them that their trainers were pleased when they complied with the task. "They are really happy to participate," Andics went on to say. "The difficult aspect of the training was to convince dogs that 'motionless' means really motionless. They can't move more than 3 millimeters in any direction, otherwise we have to throw out all of the data."

Dog Training

The neuroscientist also noted that many dog owners have experimented with trying to "trick" their dogs by making up and saying words that would be considered nonsense yet delivered in an upbeat, cheerful and/or happy tone of voice. "I think the big difference here is that they only heard us, they didn't see us," says Andics, because the dogs were inside the machine. "Here, the only information they had was the speech signal. What we saw is that for praise to be processed as a reward, when there is no other supporting information, both word meaning and intonation have to fit." Meg Ryan in French Kiss comes to mind with happy/sad, the corresponding face with the corresponding emotion.

Animal Studies

Andics made note of the fact that while the study revealed something about dogs, it also may say something about being human. "Humans seem to be the only species which uses words and intonation for communicating emotions, feelings, inner states," he said. "To find that dogs have a very similar neural mechanism to tell apart meaningful words from meaningless sound sequences is, I think, really amazing." What's more, he says, this study is important because he thinks it's the first major finding using noninvasive neuroscience with lucid test subjects without the use of restraints. "That just changes everything," Andics says. "You literally can see what's going on in their brains just like you would with people. And it's really the first time that this has led to a big discovery and I think we're going to see a lot more of this."

As more studies are undertaken with “willing volunteers,” hopefully we’ll see more information come to light in so far as the emotional and physical health and wellbeing of our favorite pets.