Reply to comment

To me, the idea of innate central pattern generators (CPG) and their coordinated control of specific actions, like walking, is startling but makes sense. I always thought that children learning to walk, or reaching out to grab anything within reach was a visually learned process and that their development of these behaviors would be different if they grew up in a different situation (without human contact, etc.). Despite this, there are clearly behaviors that we (our neurons, muscles, bodies) can just do. Breathing, the beating of a heart, and flinching away from something hot or sharp are not learned actions, nor are they controllable by an “i-function”. The motor symphonies for these actions have already been composed by our genes.

I find the ability of organisms to create new CPGs for other behaviors fascinating as well. I began playing soccer when I was six and it was definitely not an innate set of actions. Kicking a ball, aiming my passes, and using my non-dominant foot were awkward, frustrating actions. I knew what a specific move looked like but, no matter how hard I tried, I could not will my body to to recreate it smoothly and skillfully. It took me a while to realize that if I practiced passing, shooting, or even certain moves over and over again, they would become almost instinctual when I played with my teammates. And so I began creating CPGs that worked together to create a motor symphony of soccer skills. Now, when I come back from a few months off from soccer, it takes only a couple of days to get my feet moving fluidly again. I wonder if, having now created these CPGs, they can ever be destroyed? Does disuse of a certain CPG over a long period of time affect its existence? Or, can the CPGs we create during our lifetime become as innate as those responsible for breathing? In other words, when someone sits back at the piano bench after fifteen years without practice, is it just the motor neurons that aren’t used to being utilized in that manner or is it the CPG that has become weaker?