The study showed that dogs, like people, use the left hemisphere of their brain to process words, and a right hemisphere brain region to process intonation. Praise activates dogs’ reward center only when both words and intonation match.
“We showed dogs praise words and non-praise words, in both praising and non-praising intonation, and we found that dogs just like humans can separately process word meaning information … in the speech signal and intonational information,” lead researcher Attila Andics of the Department of Ethology told Reuters.
And they do it in a way that is similar to how it is done in the human brain,” he said, adding that the research was unique because how animals process human speech has not been analyzed this way elsewhere.
In the research, 13 dogs of different breeds, including border collies, golden retrievers, a Chinese crested dog and a German shepherd, were trained to lie completely motionless in an MRI scanner for seven minutes so that researchers could measure their brain activity while they listened to words from their trainers.
They had headphones on, and heard praise words in praising intonation like “super”, “well done,” “good boy,” Andics said.
Dogs heard praise words in praising intonation, praise words in neutral intonation, and also some neutral conjunction words, meaningless to them, in praising and neutral intonations.
“The reward center in dogs’ brains became activated for praise words in praising intonation but not for any of the other three combinations,” Andics said.
Andics said the new findings could lead to examining whether dogs can differentiate between speakers and meaningful sentences.
“But also beyond linguistic stimuli, whether they are really happier to hear some types of sounds than other types of sounds. Are there music they like more than other music? We now have an objective measure by looking at the reward center to answer these types of questions,” he added.