Video: The brain in love

Why do we crave love so much, even to the point that we would die for it? To learn more about our very real, very physical need for romantic love, Helen Fisher and her research team took MRIs of people in love -- and people who had just been dumped.

Anthropologist Helen Fisher studies gender differences and the evolution of human emotions. She's best known as an expert on romantic love, and her beautifully penned books -- including Anatomy of Love and Why We Love -- lay bare the mysteries of our most treasured emotion.