“In my youth, Father William replied to his son,
I feared it would injure the brain…”
Alice in Wonderland

Like Father William, I like to stand on my head more and more as I get older.  So much so that I sometimes wonder why I spend any time on my feet any more.

Twenty four by seven my eyes, the crystals in my ears*, and the myriad proprioceptors in my muscles are feeding data to my brain.  The data processes down my nerves like an endless caravan of trucks, brimming with signals about my position in the world.  My brain dutifully crunches these mountains of tiny bits, whirring along for all I know at a rate of thousands of gigabytes per millisecond.

I try to imagine building a spreadsheet that would calculate for one split instant the momentum and orientation for each part of my body. I can’t.  I wouldn’t know which cell to begin with.

And yet these are the calculations that my own brain has done effortlessly over and over and over again for more years than I care to admit. Really, it makes my head spin. You’d think the guy in the lighthouse would get bored up there, if not tired.

So here’s how I understand headstand.

Think of a swimming pool.  All summer long we splash around in the cool clarity of our spatial perceptions, making waves, dunking each other, cannonballing off the side of the pool.  Meanwhile in the darkness of a hidden shed, chanting “aum” like a devoted monk, the filter pump keeps the water swimmable.

The brain’s system of spatial orientation, like the pool’s filter pump, is what makes all of our other recreation possible.

Ever backflushed a pool’s filter pump?  You have to do it every few weeks during the summer: flip a switch that makes everything in the filtration system run backwards.  This blows the collected gunk on the filter out the other way and through a flushing pipe.

If a pool could sing, you’d hear “Allleluia!!” yodelling across the backyards of America every time someone backflushed.

For my own brain I think doing a headstand is like backflushing a pool. For a few moments all of the gravity calculations go in reverse.  The pluses in the spreadsheet turn into minuses and the timeses become divided bys.  Words like down and up float away like useless balloons.

And whatever the other tangible benefits of standing on my head – increased blood flow to the brain, decompression in the lower back, reversal of pressure in my body’s many fluidic systems –  the best part of all is this momentary reversal of currents in my brain.

Because for those few moments in sirsasana, the office clerk in my head gets to stand up (or drift down) from his chair, rub his eyes, and a have a round of Sudoku.  It’s about time; the poor guy has earned a break.

And then when I come down,   the world spins upright and the filter monk inhales to resume his chant with a fresh voice.  For that split second a few cells in the recesses of my mind relive a primal experience.

I am newly born, seeing the world again for the first time.

* “The otolith organs in the inner ear utilize small crystals to sense both gravity and body movements. They determine whether an individual is upright or tilted by sensing gravity. They also sense whether an individual is translating; i.e., moving side-to-side, up-and-down, or from front-to-back. Often the inner ear receives a combination of inputs. For example, when a motorcycle rider turns a sharp corner, the rider’s otoliths sense the combined effects of turning and gravity. In spaceflight, the inner ear no longer senses gravity because the astronauts are weightless. However, inputs from side-to-side, up-down, and front-back translation still persist. Since tilt with regard to gravity is essentially meaningless in space, it has been hypothesized that, as a result of the process of adaptation to weightlessness, the brain begins to reinterpret all otolith signals to indicate primarily translation, not tilt…”

Source:
The Neurolab Spacelab Mission: Neuroscience Research in Space
Perception of the Spatial Vertical During Centrifugation and Static Tilt