How scientists discovered the "fear center" of the brain

Fear is one of the most universally understood human emotions. Every one of us is familiar with the feelings, behaviors, and symptoms engendered by fear — so familiar, in fact, that we can sense it in the voices and actions of our friends and loved ones, and even recognize it in the facial expressions of complete… » 10/12/11 9:00am 10/12/11 9:00am