SALT LAKE CITY — The first thing to know about potential alien invaders is that the U.S. Government no longer classifies them as unidentified flying objects. That sounds too scary. They are classified as unidentified aerial phenomena. It sounds a bit better.

Alien Hand Syndrome (AHS) is a rare neurological disorder distinguished by involuntary, seemingly purposeful limb movements coupled with a sensation of estrangement from the affected limb. This condition is heterogeneous in nature, often classified into ...