Why Lucy fell out of a tree
What a jerk!
I was a skinny, somewhat nerdy high schooler with a prominent Adam’s apple. That was 56 years ago, and not a lot has changed in the intervening years.
I was certainly not part of the “in crowd,” at least not to the extent that would permit me to kick one of the school’s football players in the head and not get pummeled. But the science associated with that particular assault, however uninformed on my part, allowed me to get away with it. Well, almost!
I should explain.
Have you ever had the experience of starting to fall asleep when suddenly you have the distinct sensation of falling?
The resulting involuntary response can be a sudden and violent extending of the arms and legs. A motion intended to halt your plunge and save your life.
Sheepishly, you soon discover that you’re safely on terra firma, possibly in your Lazy Boy, and not airborne at all. This involuntary reflexive phenomenon happens to me fairly often, and always when I am just about to doze off.
High school study halls are frequently a contributing factor to student snoozing. I found studying rather dull compared to dreaming of hunting, fishing and chasing girls, not necessarily in that order.
The afternoon study hall was held in the perpetually toasty auditorium. We were crammed in like sardines in a tin. Considering that we squeezed into our seats shortly after lunch, student slumber should not be unexpected.
As for using this time to study, only the kids even nerdier than me actually studied in study hall.
Left with only the erratic and unsophisticated thoughts of an adolescent, one soon started to drift off into the Land of Nod. On one particular occasion, I had just arrived at the gates of Nod when I felt myself slide off the cloud and begin a rapid descent into the abyss.
My hands involuntarily shot out and grabbed for a non-existent tree limb. My right leg crossed over my left leg, shot out with the velocity of a Kung Fu kick.
The resulting blow from my black leather pointy-toed, Cuban-heeled, ankle-high boots (all the rage back then) landed squarely into the back of Gary Spalding’s helmetless head.
A murmur arose from those sitting near the unfolding drama. Spalding sat motionless for several moments, letting it sink in that one of the Poindexters had assaulted him. When he slowly turned around to look at me, there was a definite suggestion of murder in his eyes.
Before his brain could formulate the method that he would use to maim and humiliate me, I decided to make this a learning experience for him.
I took full advantage of the lull in Spalding’s capacity to fully grasp the immediate situation. He was still shocked that a student of my lowly station would sucker punch him from behind.
Starting with an apology, stating that I didn’t mean to hit him, I went on to say, “This is a common physiological response to falling asleep. You’ve probably had it happen yourself, right?”
(I probably didn’t actually use the word physiological for neither one of us would have known what it meant.)
Still speechless, he rubbed the back of his head and slowly nodded yes. “Great,” I thought, “I have a chance here of avoiding a very public a** kicking.”
Clearly, Spalding had an intellect rivaled only by garden tools. I had to explain my actions in terms that would be easily understood.
Anyway, I wasn’t sure that this reaction to dozing off even had a name. I considered just making up something but dismissed the idea. Then I thought about the potential of a broken nose. Finally, I proceeded with a hurriedly improvised prevarication.
I was taking, but not excelling at, Spanish at the time and recalled the word “dormir,” meaning sleep. I blurted out, “This is actually a medical condition called Dormir’s Syndrome and people that have it, can’t help it. My doctor even said that there are no medicines to control it.”
None of which is true except for the “condition” part, and that was just pure luck.
My hope for some sympathy from Spalding seemed to be working. He shook his head affirmatively again and glanced around the auditorium.
When his gaze returned to me, he flicked my forehead with his fingers and shouted, “If you ever do that again, you little dweeb, why, I’ll give you a beating as you’ve never seen.”
It hurt for sure, but it was a lot better than a black eye or a broken nose. And, I understood that Spalding couldn’t completely ignore my assault with the whole auditorium watching.
In fact, we became friends of sorts. That is, he allowed me to do his algebra homework and, in gratitude, would nod at me from time to time as we passed in the hallway.
Gravity is not our friend, friend.
OK, it is time now to depart from high school hijinks to talk science, specifically the science behind the sensation of falling just prior to entering sleep.
Is there a term for what I, and many others, occasionally experience when we reach the borders of sleep and experience a sensation of falling – accompanied by convulsive jerking?
However, to fully understand why many of us have a trait called hypnic jerk, we have to go back to the time of Lucy. No, not “that” Lucy! We have to go back in time some three million years before the red-headed comedian.
The Lucy in question was just under four feet tall and was bipedal. Like us, she walked and ran on her feet. A hominin called Australopithecus afarensis, Lucy was one of our direct ancestors. She and her kind existed during a period between ape-like creatures and modern humans.
On the ground and hiding in the bush were saber-toothed cats, reptiles and bear-sized hyenas that would consider Lucy an easy snack. So trees offered the most safety because of Lucy’s diminutive stature and the enormous predators that dominated her world.
Consider for a moment that you were a member of Lucy’s group. When you were not on the ground searching for food and water, you would spend your time in a tree. From the relative safety of a limb, you could watch the menagerie of fearsome predators pass by below.
So, imagine that you found a comfy spot on a large branch where you could stretch out your legs and rest your back against the massive trunk. You just finished drinking your fill of spring water and have a tummy full of sweet figs. *
Your thoughts drift to a source of honey you spotted earlier while drinking water from the spring. A rare but much-treasured treat. Your eyelids start to feel heavy, and you feel a much-needed nap coming on.
As you begin passing into sleep, you relax your grip on the branch and suddenly feel yourself falling toward the dangers waiting on the ground. You reach out with both hands, and one grasps solidly onto a branch, just before falling into a circle of hungry giant hyenas.
The hyenas miss a meal, and you survive another unforgiving day thanks to the hypnic jerk.
This form of a condition called sleep myoclonus results in involuntary muscle contractions as you are going to sleep. Some forms of sleep myoclonus cause muscle twitching and grasping with the hands during sleep, usually during REM sleep.
For those primates that experience hypnic jerk, there is a good chance that they will pass on this trait to their descendants. It is still present in about 80% of humans today. We continue to experience the hypnic jerk even though it is rarely beneficial since we moved out of the trees and into a suburban split-level.
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