Science writer Sam Kean joins Ira live at the Aspen Ideas Festival to talk about the brain injuries that led to some of neuroscience’s biggest breakthroughs. From “H.M.,” who lost his memory during surgery, to Phineas Gage, whose grisly encounter with a tamping iron put him into high school psychology books, Kean explains how the field of neuroscience emerged from stories of brains gone awry.