Incubi, succubae, alien kidnappers, and out of body experiences

Incubus
. pl. in·cu·bus·es or in·cu·bi (-b)
1. An evil spirit supposed to descend upon and have sexual intercourse with women as they sleep.
2. A nightmare.
3. An oppressive or nightmarish burden.
[Middle English, from Late Latin, alteration of Latin incub, from incubre, to lie down on; see incubate.] From the Free Dictionary

Succubus
n. pl. suc·cu·bus·es or suc·cu·bi (-b, -b) also suc·cu·bae (-b, -b)
1. A female demon supposed to descend upon and have sexual intercourse with a man while he sleeps.
2. An evil spirit; a demon.
[Middle English, from Medieval Latin, alteration (influenced by Late Latin incubus, incubus) of Latin succuba, paramour, from succubre, to lie under : sub-, sub- + cubre, to lie down.] From the Free Dictionary

Note the literal meaning of the Latin root of incubus – “to lie down on.” I’ll get back to that. For the classic visual of this, look at John Henry Fuseli’s painting, The Nightmare.

After waking up one morning in that vaguely disturbed state that follows a half remembered nightmare, I started thinking about a couple of types of “paranormal” experiences that have been explained by science. The first is the dream of oppressive visitation.

In the Middle Ages and beyond, people would claim to have been visited by an incubus or succubus (see above). From the advent of aliens in science fiction in the early 20th century to this day people have claimed to have…..well…to have had sex with an alien. Or, for that matter, to have been captured and tied down by an alien. It all relates to the same physical syndrome, with different cultural overlays.

It is called sleep paralysis. When we sleep, we pass in and out of REM (Rapid Eye Movement) sleep, when we dream. In this state a certain part of our brain shuts off, effectively paralyzing us. If not for this, we would act out our dreams in our sleep, thrashing around and probably injuring ourselves. A minor failure of this mechanism can be seen in the twitching paws of a sleeping dog, as it chases its prey across the lawn of its dreams. In humans, when all works correctly, we regain our motor functions as we awake. This enables us to smack the alarm clock and roll out of bed. However, with some people the timing is off and the sleep paralysis stays engaged as the person is in the process of waking up from REM sleep. Humans are pattern finders, assimilators of all parts of the perceived environment. When a fractionally awake person feels as if he or she can’t move, there needs to be a cause, and a cause is provided by the imagination. For the medieval peasant it was a demon, for the modern Westerner, an alien. Sleep disorder researchers have watched people with sleep paralysis wake up and swear that they had just been visited, once again, by an alien.

The other phenomenon is one that many people have experienced during a physical crisis. The story often goes something like this: “I was on the operating table, under anesthetic. I heard the doctor say that my heart had stopped. I felt myself rise up out of my body and found myself looking down on the operating table and the doctors and nurses around my body. They restarted my heart and I reentered my body.”

Jet fighter pilots have experienced the same phenomenon during or after sharp maneuvers. The pilot pulls out of a steep dive and experiences large g-forces, the acceleration that is like experiencing 2, 4, or even 8 times the force of gravity. The pilot partially or completely blacks out. The pilot then finds himself over his own plane looking down on himself in the cockpit. What is going on?

Neuroscientists call this phenomenon failure of proprioception. Proprioception is our internal sense of our body position and movement. It enables us, for example, to walk in complete darkness. Alcohol impairs proprioception, which is why a cop will ask a drunk to close his eyes and touch his nose with one fingertip. In rare instances of complete loss of proprioception due to neural injury, people have become essentially paralyzed, and eventually relearn basic movements by watching themselves. These unfortunates can’t look away while holding a glass of water – they’ll drop it.

Failure of proprioception can be caused by temporary loss of sufficient blood flow to the brain. In the case of the pilot, the g-forces caused blood to pool in the lower body, depriving the brain of oxygen. Depending on situation, a person can find themselves apparently behind themselves, above themselves, in front of themselves, or beside themselves. According to some accounts, the sense of being in front of your own body can result in the sufferer feeling shadowed by someone else. This probably brings us back to demons and aliens.

For a great exploration of this, listen to the Radiolab broadcast of May 5, 2006 on proprioception.

I sincerely wish you pleasant dreams.