Pettigrew found that the brain manages the external world by dividing it into separate regions, the peripersonal and the extrapersonal—basically, near and far. Peripersonal space includes whatever is in arm’s reach; things you can control right now by using your hands. This is the world of what’s real, right now. Extrapersonal space refers to everything else—whatever you can’t touch unless you move beyond your arm’s reach, whether it’s three feet or three million miles away. This is the realm of possibility.
