Hacking the Brain: The Neuroscience of Motor Learning I

One of the greatest tools at our disposal when we are learning to fence is our brains and nervous systems. It may surprise you to learn that up until a certain point, the majority of gains when learning new physical skills are neurological in nature, and are not due to increased muscle strength. The reason for this lies in how our brains and muscles communicate and how we put new movements together. As a general rule, our bodies become good at doing things that they do regularly. With repeated usage, muscles become stronger and likewise, with repeated usage, our nervous system creates new connections, yielding faster, more specialized circuits. In order to explain this more fully and demonstrate how this relates to learning to fence, I must first explain how our brain and muscles are structured and how that relates to carrying out movements. My goal for this post is to describe how our brains cause our muscles to move and how we learn new movements in order to inform the way that we train.

The Anatomy and Physiology of motion:

While we often think of muscles (e.g. biceps, triceps) as singular entities, they are in fact made up of several bundles of muscle fibers. Each of these fibers is an individual muscle cell and within each of these cells are structures called sarcomeres that allow the cell to contract. Our brains tell our muscles to contract via motor nerves. Importantly, these nerves form connections with small groups or even individual muscle fibers, allowing fine-tuned control over which muscle fibers are contracting at any given time. For the first few weeks of any new strength training regime, it is these connections that are changing, NOT the muscle fibers. Increased strength in the first few weeks occurs because the brain becomes better at activating a greater number of muscle fibers at the same time. This is also why over-training is a significant risk in the first few weeks of any exercise plan, as overtaxing the muscle early can inhibit the creation of new nerve connections.

On their own, muscles aren’t very interesting, so let’s turn our attention to the brain. As I just noted, our brains connect to our muscles through nerves that independently control very small groups of muscle fibers. The primary motor cortex of our brain serves as the output of our brain and is spatially organized into a rough map of our bodies. This region is controlled by several other brain regions including the prefrontal cortex, the cerebellum, and the basal ganglia (which we’ll talk about in part II).

What happens when we perform a motion for the first time?

In order to carry out any given motion, our brains must coordinate not just the activity of several muscle groups, but it must do this by coordinating a whole bunch of separately connected muscle fibers. As you can imagine this is a pretty complicated task, as the brain must activate the right muscle fibers in the right amounts at the right time in order to succeed. When we perform an action for the first time, our brains have to figure out in a relatively short period of time. This is similar to on the fly graphical rendering by computers. This processing is largely carried out by portions of our prefrontal cortex, an area of the brain that is largely involved in thinking, planning, personality, and consciousness, which should probably tell you that it requires active, conscious thought in order to perform.

Do we have to do this every time we move?

Fortunately, no, our brains have a way of shortcutting this processing for actions that we perform on a regular basis. With repetition, our brains store the needed pattern of muscle fiber activations that are associated with a particular motion. This process is often called “muscle memory,” but it actually involves our brains, specifically our cerebellum. Along with storing the pattern of activations needed to carry out a movement, our brains also make the pattern more efficient. To continue our computer graphics analogy, the brain stores pre-rendered graphics information for actions that it carries out regularly. To put it another way, our brains store “movies” of actions it performs regularly. When it needs to perform those actions, it simply calls up the right video presses play. Now, these actions can be of wildly varying complexity. The “templates” for very simple actions (like extending your arm) can be combined in new ways to create more complex actions (like extend your arm while turning your hand into quarta) and likewise, those actions can become even more complex (like extend your hand in quarta and lunge). Importantly, carrying out these actions will seem to be far more automatic, making them occur faster, more efficiently, and cleaner.

So, how can this inform our fencing training?

In essence, it tells us to drill, tells us how to drill, and tells us what to drill.

The key takeaway from this should be that our initial goal in training is to make our actions automatic. Doing this requires us to drill, as turning new movements into automatic movements requires repetition so that our brains learn the right sequence of muscle fibers to activate. Furthermore, because this training is based on activating the right muscle fibers in the right way, it is far more important to perform the action correctly than it is to perform the action quickly. New fencers often get tricked into thinking that fencing is about speed and strength and that they simply aren’t strong or fast enough yet. This is especially true of the SCA where we transition new fencers to sparring very quickly (here’s a sword, pointy end goes in other guy, go have fun) rather than building up a body of skills before allowing sparring (as other martial arts do). In order to combat this, drills should be carried out regularly, slowly, with proper form, and preferably supervised. New fencers simply won’t be able to tell when they’re drilling an action incorrectly, and incorrect drilling is probably worse than not drilling at all. Because it bears repeating, in my experience, the biggest pitfall here is speed. New fencers feel like they need to be figuring out how to do things (like lunging) faster rather than focusing on making it automatic first and then building speed. To help you understand what I mean by this, tonight, brush your teeth with your non-dominant hand (the one that you don’t usually brush with). Then, try doing it fast. If performing a horribly uncoordinated stabbing motion towards your throat at speed doesn’t seem like fun, imagine how that works for trying to learn fencing. The relative awkwardness of brushing your teeth (something you do all the time (I hope)) with your other hand (something you might not have ever done before) is the difference between a well-practiced, automatic motion, and an unpracticed one that requires conscious, on the fly control. The first is the feeling you want to build with your drills.

As far as what to drill, our understanding of how our brain learns to carry out new movements tells us that we should initially practice basic actions and then build complexity. In fencing, we often consider our basic footwork (advance, lunge, pass forward, pass back, lunge) to be the basic actions, but it is worth considering other actions as well. Lately I’ve been including the action of assuming guard to be an additional piece of basic footwork. I’ve also had success with some drills and exercises that work on training parts of those basic actions (leaning over a leg, hip bends, arm extensions). Working in the other direction, we build complexity by combining our basic actions into pairs first and then even more complex combinations later.

As this is getting a bit long, I will discuss how these actions become behaviors (that is, how we recognize a situation and select the appropriate action to perform) in the next segment.