OK. Maybe you're in your desk chair. You're in your office. You're in New York, or Detroit, or Timbuktu. You're on planet Earth. But where are you, really? This hour, Radiolab tries to find out.

How does your brain keep track of your body? We examine the bond between brain and body, and look at what happens when it breaks. First, author and neurologist Oliver Sacks tries to find himself using magnets. Then, a century-old mystery: why do many amputees still feel their missing limbs? We speak with a neuroscientist who solved the problem with an optical illusion. Up next, the story of a butcher who suddenly lost his entire sense of touch. And we hear from pilots who lose consciousness and suffer out-of-body experiences while flying fighter jets.