Neurology

My mother’s Parkinson’s disease changes how she walks. Not just her stride, her stutter-step, her false starts, but how she walks, her means for doing so. When she begins her stride, she breathes as if lifting something over a sill to get started. She says she has to think constantly “right-left, right-left.” The portions of her brain that used to handle the task are off the job. She’s learned to use another set of circuits, but it’s hard.

In grade school, I tried a similar experiment (though I, at least, had a choice.) Sitting in Miss Haugh’s class, trying to find something to think about other than whatever went on at the front of the room, I tried thinking about breathing – in-out, in-out. In short order, I found that this thinking had become necessary – that if I thought about breathing, I had to continue to think about breathing – the normal, unconscious function didn’t seem ready to resume on its own. Its resumption, the automatic takeover, eluded me, no matter how often I tried to catch it.

The schoolyard was full of experiments – the yellow pill bottle brought to school to open during the noise of recess, then quickly seal again. The seal was never good enough to keep the noise in, so that later, when I bent back the lid in a silent classroom, the hoped-for burst of recess noise had already leaked out in the hall.

New research has shown that monkeys, outfitted with a brain implant, can learn to control a game directly with the brain. They train with a mechanical joystick, which moves a dot on a screen. Simultaneously, a chip on the surface of the brain monitors signals from the brain that come from their moving hands When the joystick is taken away, they are able to move the dot directly by thinking of its motion. Scientists conclude that, for the monkeys, this is a limb – the monkeys make no distinction between this and their other limbs. They take its success for granted, and react to a failure the same way they would to paralysis.

Hearing this brought back the rest of that conversation with Mom. I had said that I thought this re-learning, and this development of brain centers to control motion was something we all did. An example – I fly radio-control airplanes. They are large, four to six feet across, and have all of the functions of a full-sized light aircraft – the Piper Cub has ailerons, rudder, elevator, throttle, and flaps – the same basic set as its full-scale counterpart. Flying these is tremendously difficult at first. Piloting skill does not confer much of an advantage, and airline pilots who make the mistake of trying to fly without a coach routinely fly their new models into the ground within seconds of takeoff. The challenge of translating the sight of a flying model into a basis for controlling it is exhausting to a new pilot. Most can sustain it for five to ten minutes, and then require a twenty minute break to recover.

Over time, the need for the break decreases, and pilots can react faster. For me, especially with certain models, I can relax to the point that flying becomes a form of expression, and I sometimes lose awareness of my hands- I am simply watching an airplane that does what I am thinking. Learning to fly gliders added to this sensation – their light wing loading and low power demands small inputs to the controls and perfect trim of the flight surfaces. A glider in perfect trim moves in smooth curves through space, and reacts to every rising bubble of air, every shift in the wind.

When flying the glider especially, I can feel the air. There is no other word for it. When the yellow wing and red edge sweep through a broad turn, the pressure of the wind load in the turn is an upward tug in my gut. The wobble of passing through the edge of a thermal (a bubble of rising hot air) is a texture, and a bump in the space in my mind. It is more than an awareness of wind patterns over different parts of the flying field. I can lose track of where I am flying, and simply watch the plane and feel the field.

It is a sense. An additional sense. I am sure of this.

My brain, forty-two years ago, built from its raw material a set of connections that translates an electrical signal from my fingertips into an indication of contact with a solid object, and a different signal from another place into knowledge that sugar was in my mouth. It makes new connections and new tools for interpretations. When I learned to fly an R/C plane, it built connections from my visual cortex, through some intermediary and ending in this sense. If these new connections pass through an intermediary subroutine in the form of a processed visual signal, this does not differ from my other senses. The result is the same – I feel the air. I feel the strength of my battery, and the drag of a loose piece of covering.

You can see it from behind the flight line – it’s even comical. Pilots contort as they fly – bending knees, squatting, looking over shoulders in a parody of the motion of their flying counterparts. Flying something that is coming toward you is very confusing at first – the results of controls are partly reversed. Right is left, but up isn’t down. Most pilots learn early on that landing a plane that is coming toward them is easier if they turn their bodies toward the direction of flight. They look over their shoulders at the plane, but their torsos are pointed down the runway.

For my mother, watching this mandatory experiment from the inside cannot be easy, and cannot be fun. But it does work, and it clearly interests her. Her latest gadget, a laser-aided cane (to break her concentration when she freezes by painting a red line on the ground) took a lot of explaining at the airport security station – but she enjoys the curiosity it brings from her grandchildren.

In my case, exercising this new sense relaxes me as few other things do. Flying an airplane is a thrill, but it was a surprise to learn (when I tried an actual full-size aircraft) that I prefer radio control. I can see more, and I can feel more. And to my surprise, aggressive aerobatics and the vicarious thrill of Immelman turns, torque rolls and Cuban Eights are not its most satisfying aspect. They are not as relaxing as a cool summer evening, flying smoothly and feeling the texture of the cooling air. When conditions are right, the glider will match the speed of a passing hawk, who follows it. I glide down to the field, and the hawk follows. Sometimes a pairs will gang up on it, trying to tire it out. If I dart at the ground and pull up, they’ll drop to investigate the spot, and see whether there’s anything left. We chase each other in the evening breeze.

I can fly.