>> well, this is the way the study was set up. it's in patients who have failed all medical diets. patients who have failed gastric or stomach bypass surgery. patients who underwent psychiatric evaluation and their life expectancy is significantly reduced if they can't get this morbid obesity under control. >> larry: fascinating. we're going to do a lot more investigations. can i ask you a couple questions about concussions? >> yes, sir. >> larry: west virginia has a prominent football team. major problem in nfl and college football and one of the great baseball stars sat out almost the whole year. what is a concussion and what causes it? >> concussion is either the head gets hit or the head gets moved back and forth violently that the brain moves inside the skull. our brain floats in this bath of fluid. cerebral spinal fluid.