What is the brain-body circuit? [The Brain-Body Circuit 1-1]

Chapter 1: A brief introduction to the Brain-Body Circuit

1-1 What is the brain-body circuit?

When we think about our brain, we picture a grey mass in our mind. And we think that this grey mass as a whole works a miracle called intelligence. Actually this mass is a collection of interconnected nerve fibres. Billions of them reside in our brain to control our body functions, to perform intellectual tasks and to give us the joy and annoyance with all kinds of emotions. Some of them extend to the eyeballs to look and see, some to the ears to listen and hear, some to the heart to control the beats, some to the arms and hands to move them and feel the outside world, some to the legs and feet, still many others to elsewhere in our body; in short, nerve fibres permeate all through our body to interact with the world. So when we think about our brain, we cannot stop at the picture of the grey mass.

Usually a multitude of nerve fibres cooperate to carry out tasks. The cooperation is necessitated from the complexity of the tasks. Take walking for instance. It seems so simple a task that we seldom pay attention to how our body performs the task. It is not an easy task, I assure you, and so will the robot scientists do. First of all, almost every joint in our body moves when we walk, or almost every muscle has to be controlled. We know that our toes, ankles, knees and hip move. Then the spine and the neck, this column is indeed a series of short bones and quite flexible: it flexes to absorb the swinging motion resulted as our legs competing each other to step forward. If not, we cannot keep our eyes straight ahead to watch our way. Our shoulders also move to counter the imbalance that the wild motion of our lower body causes. Even when we put both our hands into pockets, our shoulders do not cease from this balancing act. Furthermore our sense organs keep detecting the changes of the terrain: paved, rough, slippery, ascending or descending. The information keeps being translated into the orders for the limbs to adjust to the change. To walk is indeed quite a complicated task.

So many nerve fibres are involved in the task that it is imperative to keep the close communication among them. To facilitate the communication, the fibres concerning a certain task are connected each other to form a permanent workgroup. It is like an electric circuit with all the complicated wiring. So I call the workgroup of nerve fibres a circuit. An electric circuit is connected to motors, lights, speakers or sensors to perform a task. Likewise the workgroup of nerve fibres are extended through our body to connect to sensory organs and to muscles. So I prefix the circuit with ‘brain-body’; thus I call the workgroup of nerve fibres the brain-body circuit.

When we walk, our brain works so hard to coordinate the muscles and senses. Yet we do not feel a bit that our brain is working. This is the power of the brain-body circuit: once established, it works autonomously beneath our consciousness. Yet the consciousness is the key figure to establish a circuit. For example, while we learn to walk, we watch how others walk and mimic them with repeated trial and error. In the beginning our consciousness summons nerve fibres to perform the task. In time those fibres summoned start to connect each other to coordinate the task without the intervention from our consciousness. When the connections get permanent and completely do away with conscious controls, the brain-body circuit is established.

When we learn to walk, we do not learn all about walking for the first time. Then we already know how to move our limbs and how to sense the world around. Before we start to walk, we crawl around. Considering how the crawling requires the coordination of limbs, spine, neck and sensory organs, we crawl not only to strengthen our muscles but also to learn the coordination. Before then, while we cannot leave our crib or the protecting arms, we already keep moving and sensing. We are progressing from the state where we move aimlessly and to the state where we control our movements. While babies are kicking, they are establishing a brain-body circuit to move their legs at will. While babies are watching something and extending their arms to touch it or grab it, they are learning to coordinate hands with eyes, or to measure a distance with the stereovision. So we learn step by step: we begin with controlling a simple movement and with sensing the change in the world around, then develop to coordinate several simple movements to do a bit complicated move, and to use the sensory information to calibrate the move. In terms of the brain-body circuit, we build simple circuits first; then combine some of them to form a bit complicated workgroup. Again we combine the relatively simple workgroups to build a bigger, more complicated workgroup. In other word, most of the brain-body circuits are the combination of simpler circuits, and all of the circuits are the reusable parts for future circuits.

Starting from walking I get back to the crib but we can go further back into the womb: mothers feel the life within them when the unborn kicks the womb. What we can do from the day one in this world, we may have prepared in the womb.

We can know further about a brain-body circuit through our own experience: we do not need any elaborate lab-machine or a series of intricate experiments. Let us contemplate on how we walk in order to see further about the brain-body circuit.

When we are to walk on a straight line, we tend to be quite awkward. We walk without a conscious control; that is the work of the autonomous brain-body circuit. Here we falsely suppose we need to control our walk consciously in order to be very precise, and end up disturbing the autonomy. The conscious control and the well-established brain-body circuit conflict with each other.

We learn to walk and that is a very long process starting from the days while we are still in the womb. We keep establishing circuit after circuit, most of them quite a little one, until all the necessary circuits are ready and combined to walk smoothly. We learn to walk through mimicking and by trial and error, and not by following an exact guidance. As a result each of us walks differently. Some walk kilometre after kilometre to feel exhilarated; and some only to tire themselves within the first one hundred meters. In other word some walk in an efficient way and some in an inefficient way. Some people try to improve their gait for graciousness, for masculinity or for a catwalk and go through a considerable effort to succeed. The effort is lost if they stop midway before the new circuit is firmly established. They need to continue their effort until they firmly establish the new circuit for a desirable gait. When they have succeeded, they can revert back to the old way, especially when their attention slacks. Here is another trait of a brain-body circuit. Once well established, a brain-body circuit cannot be removed but can be put dormant. When you want to change your way, you establish a new circuit and attentively keep following the new way until the old way gets safely dormant.

So, you cannot remove a well-established circuit but can keep it dormant. This feature troubles us more than often when we have developed a bad habit or learned to do things in a wrong or inefficient way. Sometimes the die-hard circuit works for us. Once you learn to ride a bicycle, you can ride all through your life, no matter how long a period you spend without riding one.

I described how nerve fibres work together to perform a complicated task. But what can a single fibre do? The answer is perplexing, to say the least. A single nerve fibre does not do much: it receives a simple message and relays that to other fibres. The message takes a form of chemical molecules or electric impulses; it is more a stimulus than a message. Then how can relaying stimuli culminate into a complex task? You may find it impossible. But considering that a computer works on the simplest of the simple principles, 0 or 1, it does not look quite farfetched. Every brain of ours consists of billions of nerve fibres. Surely the number is enough to form sophisticated circuits to execute complicated tasks. We just need good imagination and enough patience to see the plan. It is often our laziness to look for something special to explain things.

We are indeed far lazier than we like to think we are. This is also observed in our reluctance to learn new ways. Once we establish a brain-body circuit for a certain task, we stick to it no matter how inefficient it is. We seem to prefer keep suffering from inefficiency for life than to take finite length of time to establish a new circuit. Reusability of a brain-body circuit can be another testimony of our laziness. We are quite comfortable to take already-established circuits and add a little something to create a new one. Then we are ready to grab whatever circuits seemingly suitable to take part in the new circuit without verifying their appropriateness. Thus we tend to end up relying on an inefficient circuit.

To summarise, the brain-body circuit is the automatic relaying system which accomplishes its task without the intervention from the conscious control. We must not forget that a brain-body circuit works on the simplest of the simple principles: ‘stimulated or not’. This simple principle forces us to re-evaluate the depth of our intelligence. And the whole questions about the brain-body circuit open our eyes to the ethics not as a set of rules but as the foundation of our goodness. The quest sends me to a long and troublesome journey, and I would like to go the distance with you.