The powerful bond between humans and dogs is one that’s uniquely cherished. Loyal, obedient, and affectionate, they are truly “man’s best friend.” But do dogs love us the way we love them? Emory University neuroscientist Gregory Berns had spent decades using MRI imaging technology to study how the human brain works, but a different question still nagged at him: What is my dog thinking? After his family adopted Callie, a shy, skinny terrier...