Imagine clenching your fist so tightly it hurts - but the hand was amputated years ago. This unusual phenomenon, known as phantom limb syndrome, challenges everything we know about how the body reflects physical reality. Patients with phantom limb syndrome can feel movements, sensations and even debilitating pain in limbs that have been removed. As new technologies begin to interact more directly with the brain, understanding these illusions has never been more important. A Common Sensation...