If you own a dog, you probably talk to it in an unique way, and you could swear that he or she understands almost every single word you say. A recent study shows that you’re not wrong at all! Dogs seem to understand both human’s words and intonation.
Various species can express and also “guess” other’s inner states by acoustic cues. Some species, like some monkeys, are capable of learning and discriminating sound sequences, associating it to specific meanings. Humans, though, have an extended vocabulary and numerous variations of saying it. Then we can separately analyze lexical and intonational cues to get a global understanding of what is being communicated. Could other species also do that?
To answer that question, a group of researchers from Hungary studied 13 trained dogs (golden retrievers, border collies, a German shepherd and a Chinese crested) using magnetic resonance imaging. They recorded vocal stimuli from dogs’ female trainer, whom they were familiar with. Vocal stimuli consisted of 4 possible combinations of Hungarian expressions and intonation: praise words in praising intonation, praise words in neutral intonation, neutral words in praising intonation, and neutral words in neutral intonation. Praise words consisted of, for instance, the usual “well done!”, while neutral words were conjunction words of similar frequency, like “however”.
In humans, lexical information is processed on brain’s left side, while intonation is perceived by regions on the right side. When praise words in neutral intonation were told to dogs in a brain-scanning machine, it was possible to see that brain response was more intense on the left side, while stronger responses were observed on the right side of the brain when dogs listened to neutral words, no matter on which intonation. These results are really interesting because they show that your dog can separately understand what you say and how you say it. Moreover, brain regions used for lexical and intonational information are similar in both humans and dogs!
Scientists also found that dog reward regions of the brain respond most strongly to verbal praises when both lexical and intonational information fit (just like in human’s brain). That means that your dog understands when you say “good boy!” with a happy feeling, much more than when you say the same thing in a neutral way.
This study suggests that brain’s capacity of separately process specific sounds and intonation can evolve in animals even in the absence of language. The long history of interaction between dogs and humans during domestication could have supported dog’s abilities in communicative and learning skills. Nevertheless, that doesn’t mean that dogs comprehend human’s words in the same way we do – it only shows that dog’s brains process the sounds of a person’s voice in two ways. Humans are still the only known species that was capable of both process lexical information and invent its use.
Attila Andics, the lead author of the study, said in an interview to CNN that “What makes dogs special is that they pay attention to human social signals, including speech. This study is the first step to understanding how dogs interpret human speech, and these results can also help to make communication and cooperation between dogs and humans even more efficient.”
Bruna de Oliveira Cassettari
Watch it here: https://www.youtube.com/watch?v=m529oUfKZ-8&ab_channel=ScienceMagazine
Andics et al., Science 10.1126/science.aaf3777 (2016).
Howard, J. Your dog understands what you’re saying, sort of. In: http://edition.cnn.com/2016/08/31/health/dogs-words-mri-study/