A team of scientists has confirmed what any dog owner would already confidently tell you: that dogs can understand both vocabulary and the intonation of human voices. The researchers, based at Hungary's Eötvös Loránd University, used functional magnetic resonance imaging (fMRI) to look at the brains of the animals during testing, revealing a lot about how their canine brains react to voices.
Science has taught us a lot about man's best friend, just recently shedding light on how Labrador's genes are to blame for their weight issues, and even revealing that the food we give them might be to blame for a decline in male dog fertility. Now, scientists have looked to answer an ancient question: Do our dogs really have any idea what we're saying to them?
To provide an answer, the team, supported by the American Association for the Advancement of Science (AAAS), trained dogs to lie motionless in an MRI scanner for several minutes at a time. They then measured the brain activities of the animals while their trainers spoke to them, using multiple combinations of words and intonation, in both neutral and praising tones.
Analyzing the resulting data, the team found that the animals recognize distinct words, and generally process vocabulary in a similar manner to humans – in the left hemisphere of the brain. The second part of the equation – intonation – is dealt with separately, in auditory regions in the right hemisphere of the brain.
By speaking a variety of words in varying intonations – both praising and neutral words, in both neutral and praising intonations – the team determined that the animals were able to understand vocabulary irrespective of intonation. However, the best responses were observed when combining praising words with praising intonation.
"This shows … that dogs not only separate what we say from how we say it, but also that they can combine the two for a correct interpretation of what those words really meant," said lead study author Attila Andics.
If you have a lot of experience with dogs, then you'll likely not find any of this information particularly shocking, but it's good to have some solid scientific proof that your beloved pet really does know the difference between "biscuit" and "walkies" no matter how you say it.
As to how this canine vocal processing developed, the researchers believe that while domestication could have played a part – supporting a rapid emergence of a brain structure allowing for the capability – it's more likely that the function is more ancient in nature. Essentially, we've learned to exploit the similarities of the canine brain to our own.
A paper on the study is set to appear in the September 2 issue of the journal Science.