Everyone knows what a knee jerk is and many would oppose the idea of developing the kind of behavior in their brains. Still, I will venture into trying to propagate the thought as economical and advantageous to the very proprietor of the stated behavior. The knee jerk is not so bad. Without having to be given much thought, it does for you exactly what it should – helps your balance.
Seriously speaking, there obviously are not any ‘knee jerks’ in the brain. The local, monosynaptic reflex is not managed by the central nervous system. The brain does not even use monosynaptic processes. Does it have reflexes?
The misunderstanding about reflexes is that they seem involuntary to many people. You say something is reflex when you mean it is not intended. The fact is that humans use reflexes for language and that those reflexes can change.
Let us take writing. I had to write phonetic transcriptions when I studied and my ‘ɑ’ for the letter ‘a’ happened to ‘kick in’ – the phonetic [ɑ] happens to stand for another type of a sound. I changed my handwritten ‘ɑ’ to ‘a’, like printed, and it has stayed so ever since. Now my reflex is to write ‘a’ for ‘ɑ’. I changed my reflex volitionally. It did not even take anything like a substantial amount of time.
Speech could be just the same. You do not think how to produce particular speech sounds. You make your [th], for example, without consciously analyzing how to position your tongue. Should you happen to need any dental intervention, your brain is going to bring your [th] into your awareness. However, just with a little practice, you’re likely to make your [th] without much focus again.
What would be reflexes doing? They’d be saving the brain’s working capacity. Paying attention to all details for language could take up your brain completely – you might need to make notes for yourself in order not to forget what you wanted to say before you analyze all the details in how to say it. Instead, the brain has reflexes to embrace contextual clusters – you do not need to remember not to say the final [b] in ‘comb’, for example. You do say the [b] in ‘combat’, however.
Working out reflexes for yourself might help also in grammar – this in another post ‘My Travel’.
Back with the ‘brain knee jerk’ thing: they say you couldn’t be the top of the world – ‘knee jerk them’; one couldn’t need to be the top of the world to have a good day 
Please feel welcome to see my scribbling site
https://sites.google.com/site/teresasscribbling/Welcome
my poetry corner
https://sites.google.com/site/teresaspoetrycorner/home
or my other WordPRess posts; they are listed at
http://teresapelka.wordpress.com/about/
