Does pro football cause brain injury?

The Super Bowl will be played in Tampa on Sunday and a group of Boston University researchers has gathered there in advance of the game. They are announcing findings of an investigation into brain injury in one former NFL player that is part of a still controversial body of evidence that may link professional football to brain damage. For more, we ask Dr. Robert Stern, an Associate Professor of Neurology at Boston University, to explain his findings and what this could mean for the NFL.