Motor Control: Science and Mystery

By browsing through some texts on motor control it is possible to get a more or less detailed idea of the incredibly complex organization that regulates the way we move.

Motor systems not only control the muscles connected to the joints of a specific movement we want to perform, but at the same time they must also control the muscles acting on other joints.
For example, if we raise an arm while standing, even before the muscles of the arm are contracted those of the legs to stabilize the movement and maintain balance.
It is possible to investigate the mechanisms that regulate these activities; however, this is a very broad topic and should be referred to specialized texts.(¹)

What I would like to bring to attention is the fact that the entire nervous system is involved in the planning, programming and execution of movement(²). From the cortical system, to the trunk-brain system, to the spinal system.
The activity also is influenced by all the sensory information that comes from the outside world and the perception of ourselves in motion, allowing constant evaluation of the movement being performed and modification of the programming of the next movement, or even a reshaping of the movement itself as it is performed, if conditions permit (³).

Research around motor control thus starts from the observed movement to try to understand how it works “from the inside,” going backwards from the muscle to the nervous system.

However, the question around the act of will remains open:
Where does the will to perform a motor act come from? How is it transformed into action?

If asked to perform a very simple movement, about 800 msec before the movement, a slowly increasing negative wave can be recorded over the entire surface of the brain. This potential, termed the expectation or preparation potential, precedes the moment when the motor cortex sends activation commands to skeletal muscles.
According to many, this preparation potential is the neuronal correlate of will, and interestingly it involves the entire cerebral cortex, not just certain areas.

So from the moment we desire to make a movement (even the simplest one like moving a finger), a wave passes through the brain, and subsequently all the electrical processes that regulate the execution of the movement are triggered.
How and from where does this wave arise?

Two considerations:

– in the Feldenkrais Method we often talk about tuning, about tuning our will to what we actually do. A class in the Method is a workshop to refine this dialogue of discovering ourselves and how we turn our intentions into action.
If I am asked to move an arm and I also contract my lips, from the moment I notice this I can refine the execution. This is why people who have been practicing the Feldenkrais Method for a long time report that their relationship with how they manifest their will toward the environment changes, 360 degrees, not just in terms of motor control.

– I always remain fascinated by how the most well-known scientific investigations that start from an observable phenomenon to trace its origin, sooner or later stop at something that some would call unknown, others mystery. Does science lead to Mystery?
Is the vastness of the universe more inscrutable or the complexity of what lies a few inches behind our noses?

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1) This post was inspired by reading “The Motor Control” – R. Nicoletti, A. M. Borghi, edizioni il Mulino

2) I am also reminded of this post from a few years ago that can give an idea of the extreme complexity of how we manage movement.

3) For example, if it is performed slowly enough – a key ingredient of the Awareness Through Movement classes.

Translated with www.DeepL.com/Translator (free version)

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