Now that we have the ability to see inside the brain without opening anyone's skull, we'll be able to map and define brain activity and peg it to behavior and feelings. Right? Well, maybe not, or maybe not just yet. It seems the workings of our brains are rather too complex and diverse across individuals to really say for certain what a brain scan says about a person. But Nobel prize winner Eric Kandel and researcher Cynthia Fu tell us about groundbreaking work in the field of depression that just may help us toward better diagnosis and treatment.

Anything that helps us treat a disease better is welcome. Doctors have been led astray before by misunderstanding a disease and what makes it better. Neurologist Robert Sapolsky tells us about the turn of the last century, when doctors discovered that babies who died inexplicably in their sleep had thymus glands that seemed far too large. Blasting them with radiation shrank them effectively, and so was administered to perfectly healthy children to prevent this sudden infant death syndrome...