At least one in four women — and a much smaller proportion of men — experiences intimate partner violence in their lifetime. For people in violent relationships, brain injuries are unfortunately common. But little is known about what exactly happens inside the brains of people dealing with domestic violence — and how these kinds of traumatic brain injuries may be different from those that come out of contact sports like football. Host Regina G. Barber talks with NPR brain correspondent Jon Hamilton about new research on the connection between domestic violence and traumatic brain injuries – and what makes these injuries unique. Questions? Email us at shortwave@npr.org.