The results revealed two main findings. First, only the GWL dogs were able to learn the names of the new toys at levels above chance. But more importantly, the GWL dogs were significantly more likely than the typical group to tilt their heads upon hearing their owners say the name of a new toy.

“Therefore, we suggest that the difference in the dogs’ behavior might be related to hearing meaningful words (for the GWL dogs) and could be a sign of increased attention,” the researchers wrote. “Possibly, head-tilts could also be related to making a cross-modal match in the dogs’ memory (e.g. name to a visual image) upon hearing the toy’s name.”

The results showed that each of the individual dogs in the GWL group consistently tilted its head in the same direction, but some of the dogs consistently chose right while the others chose left. This held true even when the owners altered their positions while giving commands, suggesting that “the location of the sound source can be excluded as a confounding factor,” the researchers wrote.