If you had to guess the most common cause of headaches, would you ever suspect the culprit is ice cream?
A surprising phenomenon sometimes occurs to people who have lost a hand. Soon after the hand is lost, they report that they can feel it again, this time when something touches the side of their face. A neurologist can lightly touch different areas on the cheek, for example, and the person will say it feels as if two spots were being touched simultaneously. One on their face, and one on their missing hand. Learn more on this Moment of Science.
Try running your fingers along your scalp. You’ll find bumps and ridges and planes. The human skull is anything but round! Learn more on this Moment of Science.