Don't Think, Feel!
The Brain Science Behind Close Range Sensitivity Drills
Introduction: Remember to Smile
There is a principle in Dacayana Eskrima that might seem a little odd to the uninitiated: remember to smile while practising. It might sound like advice pinched from a self-help book, but there is very real and very practical reasoning behind it — particularly when it comes to our close-range sensitivity drills.
Those drills include:
• Circular tapi drill — empty hand, pocket stick and knife applications, including the Alicaway system
• Close range balla balla
• Solo olisi tapi drill
And from other arts and systems that share the same underlying principles:
• Hubud (Filipino trapping drill)
• Chi Sau — sticking hands (Wing Chun)
• Push hands (Tai Chi / Chi Kung)
On the surface, the reason for relaxing during these drills seems straightforward enough: you are too close to your training partner to see what they are doing, so your response is guided by touch. The more relaxed you are, the more sensitive you become to their movements. Simple, right?
Well, not quite. If we dig a little deeper — beneath the skin and bone and into the brain itself — we can shed some light on what is actually going on, and why these drills work in ways that can feel almost mysterious until you understand the science behind them.
Part One: A Quick Tour of the Brain
The Cerebral Cortex — The Walnut on Top
The top part of the brain — the part that, in evolutionary terms, makes us most distinctly human — is called the cerebral cortex. Look at it from above and it resembles a walnut: two wrinkled halves, the left hemisphere and the right hemisphere, sitting side by side.
These two hemispheres are connected by a dense bridge of nerve fibres called the corpus callosum (sometimes called the commissure). This bridge is crucial — it is the communication highway between the two sides of your brain, and without it functioning properly, the two hemispheres would essentially be strangers to one another.
Fig. 1 — The cerebral cortex viewed from above, showing the left and right hemispheres and the corpus callosum
Left Brain — The Commander
The left hemisphere is the dominant one for most people. It handles analytical and verbal thinking: language, speech, writing, planning, reasoning, and problem-solving. It is the part of you that narrates your life, that makes lists, that argues with itself at three in the morning. It is your everyday 'I'. You might think of it as a commander, a scientist, or — and this is the analogy I keep coming back to — your adult voice.
Right Brain — The Artist
The right hemisphere is a very different character. It deals in spatial awareness, visual processing, emotional response, instinct, and musical sense. Crucially, it cannot express itself in language. It does not speak; it feels, reacts, and creates. Think of it as your subconscious — an artist, an improviser, an inner child. It is spontaneous in a way the left brain simply cannot be.
The Two Brains Working Together
In broad terms, the left hemisphere controls the right side of the body, and the right hemisphere controls the left side. But neither hemisphere operates in isolation. Information and electrical signals are constantly passing back and forth across the corpus callosum, facilitating a cooperation so seamless that we are barely aware it is happening.
This cooperation becomes especially important when we learn complex, two-sided movements — particularly those that require our hands to cross the centreline of our body. Each time we practise such a movement, we are literally building new neural connections that span across both hemispheres via the corpus callosum. The more we repeat the movement, the stronger and more established those connections become. This is what we mean by muscle memory — not memory stored in the muscles themselves, but deeply embedded neural pathways that allow the brain and body to perform complex tasks with little or no conscious direction.
Anyone who has been doing the tapi drill for a few years will know this feeling. The hands move, the transitions happen, and somewhere along the way your conscious mind drifts off to think about something else entirely.
Part Two: Three Entities, One Martial Artist
Meet Ollie, Stan, and Robbie
So we have three distinct entities at work whenever we move or respond to the world:
Ollie — The Mind (Left Brain)
The conscious commander. The planner, the schemer, the problem-solver. Analytical, verbal, dominant. The 'I' that reads these words and nods along. In Laurel and Hardy terms, Ollie is the one with the plan — always confident, always certain he knows best, always leading them into the next disaster.
Stan — The Spirit (Right Brain)
The subconscious artist. Emotional, instinctive, spontaneous. Cannot speak, but feels everything. Stan's face is a map of whatever Ollie is feeling — when Ollie is confident and positive, Stan lights up. When Ollie is frustrated or despondent, Stan crumbles. The emotional thermostat between them runs entirely in one direction.
Robbie — The Body (Muscle Memory)
The robot. Robbie does not think, does not feel, does not care. Robbie just executes. Once a movement is sufficiently drilled and the neural pathways are fully established, Robbie takes over and runs the programme automatically, freeing Ollie and Stan to attend to other things. Driving a familiar route, catching a dropped glass, shielding your face from a sudden blow — that is Robbie doing his job.
Now, these three need to work together. The trouble is, they are not always the best of friends.
Fig. 2 — The three entities and their relationships. The overlap at the centre — where all three work in harmony — is what practitioners know as the flow state
Fig. 2 — The three entities and their relationships. The overlap at the centre — where all three work in harmony — is what practitioners know as the flow state
The Feedback Loop Problem
Here is where it gets interesting — and where it gets relevant to why we practise sensitivity drills the way we do.
Ollie, for all his confidence, tends to bully Stan. When Ollie is positive, energised, and feeling good about himself, Stan is flooded with enthusiasm and performs brilliantly. But the moment Ollie turns negative — frustrated, self-critical, or rattled — he drags Stan down with him. 'That's another fine mess you've got me into' is not just a punchline; it is a perfect description of what harsh internal criticism does to our subconscious, emotional self.
And here is the other problem: when things get complicated and the pressure is on, Ollie has a tendency to muscle in and try to take over — even during those moments when Stan is doing beautifully on his own. Left brain interference in a right brain process. The conscious mind trying to problem-solve something that was never meant to be solved consciously.
When that happens, the sequence breaks down. Any experienced practitioner of sensitivity drills will recognise this immediately: you are flowing, everything is working, and then a thought intrudes — What comes next? — and the whole thing falls apart. That was Ollie waking up and grabbing the wheel.
Part Three: What Sensitivity Drills Actually Do
Putting Ollie to Sleep (Gently)
Combat happens fast. We do not have the luxury of conscious problem-solving in a real exchange — there is simply not enough time. Once Ollie has made the decision that we are in a fight and committed us to it, the job belongs to Stan and Robbie. The challenge is getting Ollie to step back and let them work.
This is where the rhythmic, cyclic nature of sensitivity drills becomes so important. All of the drills listed above share this quality: they are repetitive, rhythmic, and continuous. That rhythm is not incidental — it is the mechanism. The cycling, looping nature of the drill gently occupies and sedates the conscious mind, quieting the left brain's impulse to analyse and interfere. It gives Ollie just enough to do — maintaining the rhythm — while Stan and Robbie get on with the real work.
Think of it as a mild, self-administered sedative for the overactive analytical mind. Not sleep — more like a comfortable drowsiness.
Touch Over Sight
There is another reason why close range drills are so effective at training this subconscious responsiveness: they remove the option of using vision as a primary input. At close range, you simply cannot see what your training partner is doing. Your visual processing — largely a left brain function — is rendered unreliable. You are forced to rely on touch.
The right brain is far more receptive to tactile input than the left. The subconscious responds to touch in a way that is immediate and pre-verbal — it does not need to translate the sensation into language before it can act on it. The hand feels a shift in pressure, a change in angle, a subtle redirection, and the body responds before Ollie has even registered that anything happened.
This is the sensitivity the drills are named for. Relaxation amplifies it, because tension in the muscles creates noise that drowns out the fine-grained tactile signals you are trying to read. A tense arm is like trying to listen through a loud radio. A relaxed arm is a tuned antenna.
Building the Neural Architecture
There is a longer-term purpose to all of this repetition as well. Every time you run through the tapi drill, or work a round of chi sau, or flow through the balla balla, you are reinforcing the neural pathways that make these movements possible — and you are building the connections across the corpus callosum that allow both hemispheres to contribute fluidly to the same action.
Over time, more and more of the drill migrates to Robbie — to automated, subconscious execution. This is not failure; this is the goal. What you want, eventually, is for the basic architecture of the drill to run on autopilot, leaving Stan free to improvise within it and Ollie free to read the wider tactical situation.
This is why experienced practitioners can have a full conversation while running a sensitivity drill. Robbie has the drill. Stan is feeling and responding. Ollie is free to talk about last weekend.
Part Four: The Limbic System — The Deeper Layer
Instinct Below the Cortex
Beneath the cerebral cortex lies an older, deeper set of brain structures known collectively as the limbic system. Where the cortex is the relatively recent, rational, language-using part of the brain, the limbic system is far more ancient — shared with creatures that were fighting for survival long before language existed.
The limbic system governs our most primal responses: fear, aggression, pleasure, bonding, and the famous fight-or-flight reaction. It processes incoming information at extraordinary speed — faster than conscious thought — and generates immediate emotional and physical responses. The racing heart, the surge of adrenaline, the sudden heightening of awareness: all limbic.
In a real confrontation, the limbic system fires before Ollie has had time to form a complete sentence. Whether Stan and Robbie respond usefully to that firing depends almost entirely on what they have been trained to do in those conditions. This is why drilling under pressure — staying relaxed, maintaining the smile, keeping the rhythm even when it feels artificial — is not just good practice. It is the only way to ensure that the limbic response, when it comes, triggers trained movement rather than panic.
What the Smile Actually Does
And so we come back to the smile.
Smiling is not just an expression of how you feel — it is a signal to the brain about how you feel. The act of smiling, even a deliberate and not entirely sincere one, triggers neurochemical responses associated with calm and positive engagement. It is a direct line to the limbic system, telling it: this is not a crisis. It suppresses the stress response just enough to keep Ollie from panicking, which keeps Stan open and responsive rather than frozen and withdrawn.
Smiling also makes it physically harder to tense the jaw, the neck, and the upper shoulders — the very muscles that communicate stress back up into the brain and close down fine motor sensitivity. Relax the face, and the arms tend to follow. The antenna stays tuned.
It is a beautifully simple piece of self-regulation. One small instruction with cascading effects right through the system.
Putting It All Together
So here is the fuller picture of what is happening when you step in close, make contact, and begin to flow:
The rhythm of the drill quiets Ollie — the analytical, interfering left brain — just enough for Stan to come forward. Stan reads the tactile input with the sensitivity that only a relaxed, right-brain-led system can manage. Robbie runs the established neural architecture in the background. The limbic system, primed but not panicked, adds urgency and speed without overwhelming the process. And the smile keeps all of it on just the right side of calm.
None of this is mystical. It is neuroscience — it just happens to manifest as an experience that can feel extraordinary when everything is working as it should.
When your partner shifts their weight and your hands respond before you are consciously aware of it, that is not magic. That is Stan doing his job. Your task is to give him the conditions he needs to do it.
Don't think. Feel.
Appendix: How We Know — Split Brain Research
The Corpus Callosum Experiments
You might reasonably ask: how do we actually know that the left and right hemispheres do different things? It is a fair question. The answer comes from one of the more remarkable chapters in the history of neuroscience — one that was stumbled upon almost by accident.
In the 1930s, surgeons investigating treatments for severe epilepsy considered a radical intervention: severing the corpus callosum — the bridge of nerve fibres connecting the two hemispheres — in order to prevent the runaway electrical storms of a seizure from spreading from one side of the brain to the other. The logic was straightforward: if the two hemispheres could not communicate, the seizure could not cross over.
The surgery worked. Seizure activity was dramatically reduced in the patients who underwent the procedure. But the neurologists who followed up these 'split brain' patients began to notice some deeply curious side effects — effects that, once you understand them, illuminate the distinct characters of the two hemispheres with startling clarity.
The Left Eye, the Left Hand, and the Silent Right Brain
Here is one of the experiments that produced the most revealing results.
When a split brain patient was shown an object — say, an apple — but only to their left eye (with the right eye covered), and was then asked to say what they had seen, they could not answer. They reported seeing nothing. This is not because their left eye was impaired. It is because visual input from the left eye is processed by the right hemisphere — and the right hemisphere, severed from the left, could no longer communicate what it had seen to the language-producing left hemisphere. The right brain knew what it had seen; it simply had no way to say so.
But here is where it gets fascinating. If the same patient was asked not to describe the object, but to reach out with their left hand and draw or write what they had seen, they could do it. The left hand is controlled by the right hemisphere — so the right brain, unable to speak, expressed itself through drawing and writing instead. The knowledge was there. It just could not come out as words.
This gives us a remarkably precise window into the nature of our subconscious, right-brain self. It perceives, it knows, it can act — but it does not speak. It communicates through movement, instinct, image, and feeling. Which is, when you think about it, exactly what it does in a sensitivity drill.
The Alien Hand and the Battle for Control
Some split brain patients reported an even stranger phenomenon, sometimes called 'alien hand syndrome.' The left hand would occasionally act in ways that seemed to contradict the patient's conscious intentions — buttoning a shirt while the other hand unbuttoned it, for instance. In these cases, the two hemispheres, no longer coordinated by the corpus callosum, were effectively pursuing different agendas at the same time.
This is a fairly dramatic illustration of something that, in less extreme form, all of us experience: the internal conflict between the analytical, deliberate, language-using left brain and the spontaneous, reactive, non-verbal right brain. In the split brain patients it became literal and visible. In the rest of us it tends to manifest as hesitation, internal argument, or the kind of overthinking that destroys a perfectly good flow in a sensitivity drill.
When Ollie grabs the wheel, you feel it. The hands slow down. The rhythm breaks. The connection drops.
A Note on Intuition
The split brain research also gives us a more grounded way of thinking about what we sometimes loosely call intuition. When we talk about a gut feeling, a hunch, or the sense that something is right without being able to fully explain why, we are in a sense describing the right hemisphere's capacity to process information and generate responses without being able to articulate them in language.
Various contemplative traditions have long used rhythmic or repetitive practices — the shuffling of cards, the casting of coins, the repetition of mantras or prayers — as ways of quieting the analytical mind and allowing a more instinctive form of perception to surface. I am not endorsing any particular belief system here, and I want to be clear about that. What I am saying is that the neurological mechanism these practices appear to engage — calming left brain chatter to allow right brain processing to emerge — is entirely consistent with what the split brain research revealed. The traditions may have got the explanation wrong; they may well have stumbled on a real effect by entirely different means.
What sensitivity drills do, in this light, is the same thing — but in a rigorously physical and testable context. The rhythm sedates the left brain. The touch activates the right. The corpus callosum, fully intact and functional, allows the two to work together rather than against each other. And Robbie, down in the engine room, keeps everything running.
The Takeaway
The split brain research confirmed what martial artists had been discovering empirically for centuries: that the conscious, analytical mind — for all its power and usefulness — needs to be managed if the body is to respond with genuine speed and sensitivity. The corpus callosum is the infrastructure that makes harmony between the two hemispheres possible. The sensitivity drills are the training method that teaches them to cooperate.
When everything is working — when Ollie is calm, Stan is flowing, Robbie is on automatic, and the limbic system is providing energy without panic — the result is something that experienced practitioners describe as being in the zone. It feels effortless. It feels like someone else is doing it.
That someone else is Stan. You have been trying to introduce yourself to him for years.
Now you know what to do: relax, make contact, and remember to smile.
— Dacayana Eskrima UK