Example learning material: Reactions and human physiology of driving, Introduction
Driving is a reaction-based sport, in contrast to a more fitness-oriented sport such as running. Drivers
react to where they are on track, what the car is doing, and what is going on around them. They need
quick reactions, but those responses are very specialized. First, let’s look at what a reaction is on a
A reaction has three parts: stimulus, processing, and response. Think about one of the most basic
reactions, where the doctor taps your knee with that little hammer and your leg kicks up (called a deep
tendon reflex). The stimulus is sensory neurons detecting stretching in the tendon below your knee cap
(your patellar tendon). The processing is nothing more than the sensory nerve directly exiting a motor
nerve in your spinal cord. And the response is that motor neuron exiting your quadriceps muscle in your
thigh to contract, causing the kicking motion. Tap, kick.
Though we are all every different people, the things that we are made up from, like proteins, and all
identical, down to the molecules. The various proteins in the nerve cells in one person’s body are not
just similar to those in another’s, they are absolutely identical, built from the exact same DNA blueprint.
Our differences are in things like the skeleton and muscles themselves, which vary from person to
person. The stronger the muscle is, the bigger the kick, so strengthening the muscle can affect the
response phase. But the nerves that control all of this are exactly the same; it’s all in how you use them,
and that can all be trained.
A deep tendon reflex is an example of the most basic type of reaction, one that does not include any
direction from your brain. Doctors use it to test how well the systems involved are working (sensory
nerves, motor nerves, skeletal muscle). These things are analogous to the wiring loom in a car.
Assuming they are working as they should, the time it takes for this process to occur is constant, and try
as you might, you cannot speed it up – you can’t practice deep tendon reflex responses and make them
Now consider the other end of the spectrum: a word problem needing a written answer. Here, the
stimulus is the written question, which requires our brain to see and interpret the text. The processing
is our brain analyzing the question and determining an answer. The response includes the brain
directing the words of the answer and the actual motion of the pen to make the letters.
This example is much more complex, but take a minute and think about how much of that process is
streamlined by your brain. You don’t look at each individual letter. Instead, you take in entire words,
sometimes entire phrases or even sentences. You compare what you are given with past experience.
What kind of question is it? Have you heard something like this before? How did you respond and was
it the right answer? Do you need to know more, or calculate anything? Is there a trick hiding in the
wording? The response is also streamlined, as we certainly don’t consider the way we need to hold the
pen or form the letters, we just write it down. So, our past learning and experience plays an enormous
part in the process. To someone who has not learned to read or write, this is an impossible task. But we
know that being illiterate in no way means you are incapable of reading and writing, only that you
Now consider something more in the middle: the center on a basketball team, defending against the
sudden mover of an opponent with the ball at the top of the key. Here, he is processing an enormous
amount of information, but it is all subconscious. He is aware of the other players around him, how they
are interacting, where they are moving, and where openings are forming or being shut. He cannot
simply watch the ball, but must instead look for cues in his opponent, where he is leaning, where he is
looking, where he is carrying his weight. When the other player starts to move, there is no time for
mistakes: he must predict what his opponent is going to do, or he will be left in the dust. There is no
time for conscious thought, it must all be “instinct.” The reaction requires trained visual input, a
coordinated neuromuscular response, and strong muscles to carry out the intended movement.
In situations such as this, it appears to a fan in the stands that the player has lightning-fast reflexes,
because a good player is already in motion before someone with less experience even knows what is
going on. But that is not dependent on the speed of the reaction, it is earlier recognition of the situation
and earlier and more precise initiation of movement. We are all basically the same physiology –
remember, you can’t speed up the wiring loom. But experienced players have the ability to read the
game, so that they are moving before someone less experienced even knows what is going on. It is
chess at full-speed. On top of that, expert players have trained the response phase: their movements
are strong, coordinated, efficient, and precise.
How important are the different phases? Consider one more example: tennis. Tennis is very physical,
requiring excellent speed and agility. And yet an experienced tennis player who is out of shape will still
easily beat even the fittest person who doesn’t know the game. That gives you an example of the
importance of the stimulus and processing phases: reading the other players movements and
anticipating where the ball is going, knowing the best placement for a return hit without having to think
about it, and executing that return. Just like racing, experience trumps fitness. But any tennis player’s
game will suffer as they fatigue. Some balls will be too far out of reach, some returns not as fast or
precise. And this is where fitness comes back into play, because when skills are evenly matched, the one
with the strength and stamina to continue performing at their highest level will come out on top. And
this is why to be truly elite in any discipline – including driving – you have to be in top physical condition.
As a driver, if you are not fit, you are leaving speed on the table.
So despite their vast differences, these examples are fundamentally all the same: stimulus, processing,
response. And when we talk about improving driver reactions, this is what we are talking about. The
experienced driver has mastered all three phases. To the untrained eye, this appears to be just short of
magical, but it is not; it is simply learning to recognize the stimulus, processing the information, and
So, to understand what we can all do to drive to the best of our ability, we break down each phase,
evaluate what is going on, and consider how best to improve upon our current skill.
If you are a racer, the words “seat time” probably just passed through your head. In the racing world,
seat time is practice. But like any other sports, the way you practice is extremely important. Practicing
correctly leads to improvement, practicing incorrectly leads to developing bad habits. And at every level
of racing – especially for the amateur – seat time is limited. Which means there is much more time for
training outside the car. The trick is to make the best use of that time, because the real limit on how
good you can become as a driver is time.
Stimulus, processing, response.