This is Callie, one of the dogs used in the study. Carol Clark, Emory University Dogs pay very close attention to human signals — especially when it means there's food involved.

Gregory Berns at Emory University in Atlanta was the first to take brain scans of dogs that were fully awake and unrestrained and figure out what they're thinking.

Berns and his team trained the dogs to sit in an MRI tube and watched how they responded to different signals. Here's an example provided in the study:

In the first experiment, the dogs were trained to respond to hand signals. One signal meant the dog would receive a hot dog treat, and another signal meant it would not receive one. The caudate region of the brain, associated with rewards in humans, showed activation in both dogs when they saw the signal for the treat, but not for the no-treat signal.

“These results indicate that dogs pay very close attention to human signals,” Berns says. “And these signals may have a direct line to the dog’s reward system.”

Here's a video of the study posted by Emory: