Tag: cerebellum

Learning to Move: Three Kinds of Learning

(This post’s image is a photo I took of my yoga gear. Specialized tools like my mat, blocks, and strap work together to make my practice possible. They extend my body, and help arrange it in the ways my mind imagines)

I was pretty sedentary as a kid, and didn’t get serious about physical fitness until I was an adult. One nice thing about that is I got to watch myself learn, knowing all I do now about the brain. By practicing yoga and working with physical therapists, I’ve learned a lot about myself, but also how mind and body work together. Mastering a new physical skill actually recruits at least three separate learning processes working together. Understanding this changed my expectations, helped me gain more control over my body, and made exercise much more enjoyable.

When I first started yoga, I was startled by how little I knew about my body. My teachers were asking me to observe and discern sensations I’d never noticed before. They asked me to get into certain poses, using certain muscle groups, and I didn’t know how! I didn’t have the names for these things. Worse, I could see what I was supposed to do, but I didn’t know how to make my body do that, or even if I could. It was frustrating.

It’s weird to think how ignorant we are of our bodies, given that we live in them our whole lives. For me, a prime example comes from physical therapy. When recovering from an injury, I relearned how to walk up stairs. I’ve climbed stairs thoughtlessly my whole life, and I never considered there were different ways to do it. But the leg is controlled by opposing muscle groups. I used to climb stairs by lifting each leg, using just the muscles on the front side. I learned to also use the muscles on the back side, to push up and straighten the leg. Either set of muscles can do the job alone. Now, I consciously try to balance the effort from both sides, but this never would have occurred to me without knowing a little anatomy.

That knowledge was game changing for me, but unfortunately knowing how the body works isn’t good enough. I can memorize anatomical diagrams, muscle names, and facts about body mechanics, but the only interface between the brain and body are the spinal nerves. How’s the brain supposed to know what nerve impulses correspond to which movements? There’s actually a region of the brain dedicated to this problem, the cerebellum, but it’s not consciously accessible. This is why yoga instructors use cues: they teach little mental tricks for recruiting muscles, and associate them with relevant postures.

Try this. Bend your elbows ninety degrees to extend your forearms out from your body, palms up. Imagine someone’s handing you a heavy platter. You might notice the trapezius and rhomboid muscles engage between your shoulders. These muscles largely serve a supportive role. For many people, they aren’t needed much in daily life, but using them can improve posture and reduce strain on other muscles. The problem is, they’re easy to ignore and hard to describe. But I can turn them on with the cue, and then I can learn what it feels like to use those muscles. Once I can tell whether they’re working, I can often activate them at will. Or, I can just use the cue, as needed.

Of course, conscious knowledge of form and cues are just step one. Muscle control is mostly unconscious, and for good reason. Remembering all the cues, monitoring my body, and continuously correcting my posture is work. It takes my full attention, leaving no room for anything else. Luckily, that’s just a phase. With enough practice, my cerebellum learns the patterns and can take over. I can hand off that work to my unconscious motion control sub-processor, freeing my conscious mind to think about something else.

This is why physical therapy can be so effective. After an injury, some muscles and joints may not perform like they used to. Some links between mind and body might even be severed or scrambled. Recovery means learning new ways to do old activities. At first, this is a nightmare. Without the support of the cerebellum, even just walking is an intensive conscious effort. Physical therapy can be a painful, tedious, and drawn-out process, but for many patients it makes a world of difference. It teaches the cerebellum new motion programs. Potentially, walking can become fully automatic again. The conscious mind can be used to retrain the unconscious mind in profound and lasting ways.

Yet knowing how to move isn’t enough if the body can’t follow through. The hardest part about learning a new physical activity is that the body usually isn’t ready for it. When I first started yoga, my muscles were weak, rigid, and lazy. They quickly became tired and sore, which just made me want to use them less. They struggled to move my body weight, and were so tight that my range of motion was limited. Some postures were hard, uncomfortable, or impossible. I couldn’t keep up, and when I pushed myself harder, I only injured myself.

That taught me a lesson about patience and acceptance. My body wasn’t ready, so I couldn’t do those poses, but I could work towards them. I learned to listen to my muscles complain, and to distinguish between different sensations. Some indicate hard limits I should not push past, but most are just signs of stress, and those can be good. When muscles, bones, and tendons get stressed, they respond by becoming bigger, stronger, and tougher in a process called anti-fragility. The discomfort I feel is just that physical learning process in action. By embracing the discomfort, I could slowly reshape my body.

Anti-fragility doesn’t involve the brain, conscious or unconscious. It’s a kind of learning that happens in the body tissues themselves. My muscles “know” whether they are getting the job done. They can tell if they are actually contracting and relaxing when they get the signal, whether that was easy or hard, and whether they sustained any damage in the attempt. They recognize how often they are put to use, and whether they are usually exhausted or ready for action.

Generally speaking, muscles conserve energy by doing as little as possible. But when I regularly demand more of them, they adapt. They become bigger, stronger, and more responsive. They consume more energy at rest so they’re always ready for action when I need them. They become less lazy, working harder by default, which makes them stronger still. This requires more protein to build the muscles, and more calories to power them. So my metabolism adapts, too. I eat more and my body burns more calories continuously, rather than storing them as fat.

What’s so fascinating is how all three ways of learning work together. With conscious thought, I choose to change my behavior. I master new facts and cues, so I know what I’m doing at an intellectual level, and can execute new skills (poorly, at first). With practice, not only do I refine those skills, but I engage an unconscious learning process that makes them fully automatic. I can focus my mind on the task I want to accomplish, and trust my body will just perform all the complex movements I need to pull it off. My muscles may not be up to the challenge at first, but that’s fine. With willpower, I push my tissues to their limits, and they learn to do what I ask. By the principle of anti-fragility, my body automatically remodels itself, increasing strength, flexibility, or stamina precisely where they’re needed. It makes itself a better robot, one that can live the lifestyle my mind consciously chooses. These three learning processes work independently, yet together they make a dynamic human being, one that can just as well become a yogi, a warrior, a marathon runner, or a weightlifter.

Intelligence isn’t just about brains, it’s about bodies, too, and about multiple intelligent systems working together in complex ways. I hope this was a helpful example, but as always I’m looking for feedback. Is this an experience you can relate to? Have you observed these different systems within yourself? Do you think it helps to know what’s going on intellectually, or do you approach physical training in a different way? Any other thoughts or observations to share? I’d love to hear from you in the comments.

Learning to Move

Most people identify their intelligence with their conscious mind. That’s the part that knows it’s intelligent. That’s the part that understands and makes decisions. But looking closely, there’s plenty of intelligent things we do below the conscious level. Perhaps the most striking example is movement. We use our bones and muscles continuously during our waking hours. We learn complex motor skills and perform them over and over again with great precision and reliability. Yet, we rarely think about how we do those things. It’s actually an under-appreciated superpower that helps us multitask, overcome injuries, and adapt to new opportunities over evolutionary time. How does that work, and what does it teach us about intelligence?

The human body is a large and complex machine. Over 200 bones give our bodies shape, support their bulk, and articulate through 400 joints. Over 600 muscles hold those bones together, move them relative to each other, and maintain position and posture. Unlike a building with a rigid, static structure, the body is like a floppy ragdoll. It can only hold a shape through the constant effort of its muscles. Imagine a team of circus workers, lifting a long tent pole by ropes tied to the top. They work together to overcome gravity, hoisting the heavy thing and keeping it in a precarious upright position. They carefully balance the forces from all directions, adjusting how hard they pull to keep the pole vertical, even compensating for the wind if necessary. Now imagine another tent pole balanced on top of that one. Then another, and another… it’s pretty amazing that the body can perform this feat at all.

And that’s just for standing still. Actually moving the body in useful ways is much more difficult. It requires the same coordination of many muscles, balancing and constantly adjusting their effort to hold a bone in position, but now the joints need to move. The body must choreograph, synchronize, and precision control dozens of muscles for even small, subtle movements. Thankfully, all of this is completely unconscious, because doing it manually would be a nightmare. To get a sense of this, check out the game QWOP. It’s a stupid, frustrating game, but a good illustration of the problem. It’s much easier to unconsciously control the thirty-odd muscles in each hand to type those four letters than it is to consciously control the four simulated muscles that make the QWOP guy run.

How do we do it? The brain has a dedicated subprocessor for controlling the body. The largest part of the human brain is the cortex, home to our perception, comprehension, higher level thought, and decision making. It’s a sort of general purpose computer that works across many modalities. Below that are several special-purpose brain regions that serve as an interface to the body. They are “neural networks” by definition, but with highly specialized design and function very different from the cortex. One of these brain regions is the cerebellum, and its main job is to produce precisely timed sequences of nerve impulses to control the body. We aren’t conscious of what’s happening in the cerebellum because it’s actually much older than our conscious minds. Every vertebrate has one, going back hundreds of millions of years.

The key trick to the cerebellum’s function is a feedback loop. The cerebellum doesn’t just “move the body.” It can only get it right by constantly monitoring how the body and each muscle responds to its signals, noticing any deviations from the ideal, and then adjusting its signals to compensate. This is necessary, because the body has to perform in any position, even under the influence of outside forces, even when some muscles are stiff, weak, tired, or injured. There’s no fixed control program that can work in all of those circumstances, so the cerebellum must adapt in real time. This is also how it learns. Each error is a lesson for the future. With practice, the cerebellum gets better at predicting how the body will respond to its signals, the errors get smaller, and the necessary corrections become more subtle.

As an example, my cerebellum wasn’t born knowing how to do yoga. I had to learn by trial and error. When I first tried getting into those shapes, I did a pretty bad job of it. My form was sloppy, and “wrong” in many details. My balance was precarious. My motion was awkward and jerky. I overused some muscles and neglected others entirely. But my teachers pointed out what I did wrong, and I made corrections. By performing the same motions again and again, learning what the right posture feels like and what adjustments to make, I built up muscle memory. Now I can just think “warrior II” and my body delivers effortlessly. I taught my cerebellum a new motion control program, and now I can invoke that program at will.

The real value of this unconscious mastery is how it frees up my mind. For instance, when I walk a familiar path, it’s like turning on autopilot. While my cerebellum takes care of putting one foot in front of the other, my default mode network can reflect, imagine, and make plans. This is a powerful form of multitasking, but it’s not always desired. For instance, in my yoga practice, I pay close attention to what my body is doing, even though that’s no longer necessary to perform the poses. The result is increased awareness, precision, and control in my movements, both right now and in the future. Practice lets my cerebellum refine its programming and learn layers of nuance that increase my skill level, but only if I pay attention. In other words, mastering a movement gives me the freedom to turn my mind to other things, or to focus on the performance, resulting in better quality and learning. I can’t do both at the same time.

The ability to control large, complex bodies and to think about other things at the same is amazing, but the cerebellum’s adaptability is even more important. Although some vertebrates are born knowing how to walk or swim, we all learn new ways of moving. This is how we adapt and recover after an injury, whether it’s a twisted ankle or a lost limb. It’s also how many species are able to use tools. The cerebellum doesn’t have a fixed image of the body and its limits, it can learn to contract or expand that image as needed. This also means it can learn to operate whatever body it’s born into. Vertebrates have evolved a huge range of bodies which can swim, crawl, walk, dig, climb, or fly. Each new form started off as a “birth defect,” but thanks to the adaptive powers of the cerebellum, sometimes these were not fatal flaws, but opportunities to explore new ways of living.

This is just one example of how our unconscious intelligence improves our daily lives and our ability to adapt over evolutionary time. This one happens to be part of the brain, but not the mind as we usually think of it. How does this fit with your experience? What’s it like coordinating the conscious and unconscious parts of your brain? If you’re into athletics, how do you think about training your mind as well as your body? Does this raise any more questions for you about how we think and move? If so, I’d love to hear from you in the comments.