For many of us, dogs are loyal friends and companions, but we know very little about how they see the world. On this week's Please Explain, we look at what we know about how dogs perceive the world and how dogs can be trained to help in search and rescue efforts.We’re joined by John Bradshaw, the Director of the Anthrozoology Institute at the University of Bristol and the author of Dog Sense: How the New Science of Dog Behavior Can Make You a Better Friend to Your Pet and Alexandra Horowitz, Assistant Professor of Psychology at Barnard College and Director of the Dog Cognition Lab and the author of Inside of a Dog: What Dogs See, Smell, and Know.