In most tests of general intelligence, dogs rate as reasonably clever, but nothing like primates. The one place where dogs beat primates is in interacting with humans. It’s not clear whether dogs are better at reading human intentions or simply more motivated to act on them, but dogs truly seem to get us.

Now, researchers in Hungary have tested dogs’ willingness to cooperate with us by getting them to sit still in an MRI machine. By tracking the dogs’ brain activity, the researchers were able to determine that dogs can recognize not only words, but the emotional tone behind them. Dogs recognize when both words and tone indicate praise. That’s when they feel rewarded.

The work was performed by a group of researchers based in Budapest, which becomes important when we get to the words the dogs were responding to. The hypothesis behind their work: dogs can recognize both the meaning of what’s being said (technically, its lexical content) as well as the intonation used in saying it. In other words, it’s not enough to say “good boy” to your dog—you have to sound like you mean it.