Today’s Alien Yet Truly Morbid Fact!
While lounging around one afternoon in the spring of 1908, a middle-aged German woman felt an unseen hand grip her throat. She thrashed and gasped as it crushed her windpipe, and only after a great struggle did she manage to pry it loose with her right hand. At which point the offending hand – her own left hand – fell limply to her side. A few months prior, on New Year’s Eve, she’d suffered a stroke, and ever since then her left hand had been lashing out like a rotten child – spilling her drinks, picking her nose, throwing off her bedcovers, all without her conscious consent. Now the hand had choked and bruised her. “There must be an evil spirit in it,” she confessed to her doctor.
Two similar cases popped up in the United States during World War II. Both victims, one woman, one man, suffered from epilepsy and had had their corpus callosums surgically severed to head off seizures. (The corpus callosum, a bundle of neuron fibers, connects the left and right hemispheres.) The seizures did quiet down, but a distressing side effect emerged: one hand took on a life of its own. For weeks afterward the woman would open a drawer with the right hand and the left hand would snap it shut. Or she’d start buttoning up a blouse with her right and the left would follow along and unbutton it. The man found himself handing bread to his grocer with one hand, yanking it back with the other. Back at home, he’d drop a slice into the toaster and his other hand would fling it out – Dr. Strangelove meets The Three Stooges.
As more and more cases emerged, neurologists started calling this syndrome “capricious hand” [my personal favorite – DeSpair] and “anarchic hand,” but most now refer to it as alien hand – the unwilled, uncontrolled movements of one’s own hand. Alien hand can strike people after strokes, tumors, surgery, or Creutzfeldt-Jakob disease, and while cases usually disappear within a year, sometimes the hand anarchy persists for a decade.
Through autopsy work,neuroscientists have determined what sort of brain damage causes alien hand. First, victims probably suffer damage to sensory areas. Those areas provide feedback whenever we move our arms voluntarily, and without that feedback, people simply don’t feel as if they’ve initiated a movement themselves. In other words, victims lose a “sense of agency” – a sense of being in control of their actions.
Hand-to-hand combat – with one hand undoing the other’s work (pants up/pants down) – usually arises after damage to the corpus callosum, damage that disrupts communication between the left and right hemispheres. The left brain moves the right side of the body, and vice versa. But proper movement involves more than just issuing motor commands; it also involves inhibitory signals. When your left brain tells your right hand to grab an apple, for instance, the left brain also issues a signal through the corpus callosum that tells your right brain (and thus, left hand) to cool it. The message is, “I’m on it. Take five.” If the corpus callosum suffers damage, though, the inhibition signal never arrives. As a result the right hemisphere notices that something’s going on and – lacking orders not to – lurches with the left hand to get in on the action. It’s really an excess of enthusiasm. And because most people perform most tasks with their right hands, it’s usually the left hand that jumps in late and causes this type of alien anarchy. Overall, left hand-right hand combat usually involves the weaker half rebelling and trying to win equal status for itself.
Morbid Art Du Jour!
Her art ain’t for wimps!
(Thanks to Anna for the link.)
Sarah Sitkin is a Los Angeles based artist. Her sculptural works are made in wide variety of media including but not limited to silicone, clay, plaster, resin,and latex.
Check out more of her gruesome goodness at her official site.