>> rose: charlie, underwriting by the simons foundation coming up. the charlie rose brain series is about the most exciting scientific journey of our time, understanding the brain. the series is made possible by a grant from the simons foundation, their mission is to advance the frontiers of research in the basic sciences and mathematics. >> funding for charlie rose was provided by the following. captioning sponsored by rose communications from our studios in new york city, this is charlie rose. >> tonight we continue to exploring our brain with the conversation about pain. pain serves a very important function for us to survive, it teaches us what to avoid and lets us know when to seek medical help. at the same time, though it can create tremendous suffering. st. augustine once said the greatest evil is physical pain, 100 million americans live with it every day would yo would wouo doubt agree, pain knows no boundaries, regardless of age and race, beyond the physical symptoms the experience of chronic pain often leads to feelings of isolation and hop