The death of Adolf Hitler; a Bible that promotes adultery, and the brilliant disguises of desperate British sailors–what do these stories have in common? They all hinge on secrets hidden deep inside the human brain. The fact is that history is riddled with examples of people being fooled by simple tricks designed to confuse the human brain. The question is why do they work and why do we keep falling for similar deceptions? In this hour, we'll find out why our brains are so easily fooled by simple tricks of vision, and how these tricks have been used throughout time to change the course of history.