In this short video, sounds are played from both sides, but the dog turns his head. (Credit: Ratcliffe et al.)
In one part of the experiment, a familiar command ("come on, then") was digitally stripped of any emotional tone. Hearing this, the dogs turned to the right to process the message - the human equivalent of thinking about the dictionary definition of a word. When the intonation of the message was artificially pumped up, the dogs turned left, using the other side of their brains to decipher tone or emotion. The study is even more evidence that dogs are listening "not only to who we are and how we say things, but also to what we say," Ratcliffe said.
Dogs aren't going to be composing poetry anytime soon, though, as Tufts University veterinarian Nicholas Dodman, who was not involved with this research, told CBS News. But, he emphasized, this study shows just how attuned dogs are to the emotion and words in our voices.
Not only do behavioral studies like this support the idea of canine understanding, but MRI scans also indicate that dogs have brain patterns that mimic those in humans. Despite the roughly 30,000 years dogs have spent alongside humans, dogs don't interpret speech in our word-for-word way, Ratcliffe cautioned. But that doesn't mean dogs have weak vocabularies - take Chaser, whose 1,000-word-repertoire is certainly nothing to wag a stick at.