Dogs really do understand that words stand for objects

Dogs seem to understand that words represent specific objects, recordings of their brain activity suggest.

Although some dogs can fetch a wide range of different objects on command, few do well on such tests in the lab. In addition, it is unclear if dogs understand words as object names, rather than instructions.

To explore this question, Marianna Boros at Eötvös Loránd University in Budapest, Hungary, and her colleagues tested 18 dogs from a wide range of breeds, including Border collies, toy poodles and Labrador retrievers.

Their owners chose five objects familiar to each dog. In the test, they said the name of an object and then showed the dog either the named object or a different object.

Each dog’s brainwaves were monitored via electroencephalography (EEG) to see whether there was a difference in activity when the dog’s owner said “ball”, but showed a stick, for example, compared with when the word and object were the same.

“The idea was that if dogs understand the meaning of the words, their brain responses will differ between the presentation of matching and mismatching objects,” says Boros.

The researchers found that the EEG signals were different when the objects didn’t match and the effect was stronger for words that individual dogs knew well. This is similar to results seen in humans and suggests that dogs know that certain words represent certain objects.

“The most important realisation of this study is not only that non-humans are capable of understanding words referentially, but this capacity seems to be generally present in dogs as well,” says Boros. “This study demonstrates that dogs may understand more than they show.”

No breed appeared to show a greater language ability than any other, says Boros.

Susan Hazel at the University of Adelaide, Australia, says the study adds to the knowledge of dog cognition.

“I think dogs both understand more and less than what we realise,” says Hazel. “This research shows dogs appear to make a mental representation of a word they know – for example a ball – which is not at all surprising to most dog owners who know how their dogs understand some words.”

On the other hand, she says, many dog owners anthropomorphise their pets and attribute emotions and comprehension abilities to them that don’t exist.

“Dog cognition is now one of the most studied areas around the world,” says Hazel. “I love all the research on dogs, but would love to see more on other animals we live closely with – cats, rabbits, horses.”