Control of Congress is at stake in this November's U.S. midterm elections. In today's highly polarized political environment, Republican and Democratic partisans have staked their positions on the key issues, and debate does little to persuade them. Social scientists have shown that Americans are sorting themselves into like-minded groups. Now neuroscience may explain why people rarely change their minds on deeply held beliefs, even when presented with the facts. VOA's Steve Baragona has more.