Can anyone explain how a late onset completely destroys a previous stable system even when going back to low stress-demand situations? I can almost fathom that when the stress/load is large enough the system jams and breaks down AT THAT LEVEL but why does the system break permanently in the previous lower stress/load levels? Is there a physical rewiring that sets due to the low plasticity? Is it like a breaking dam that once broken is never fixed? Any thoughts?That is a good question leading to a good debate. I wish more people would ask such questions. Here is my answer:
- a person who has a late onset might already have an on-the-edge stable system. Such systems are very common in all kinds of situations. Think of a transport system, where you have not jam and just five minutes later there is a jam.
- a late onset is not destroying the stable system, but a relatively small change in neurotransmitter levels or neurological incident can push a stable system over the edge. And this is not destruction but modulation of the capacity of the system.
- the over-the-edge is not dramatic but just noticeably increases frequency and length of a jam in the brain under high stress/demand.
- this low capacity system leads to learned behaviours (secondaries or associations of letters with jams) and cognitive beliefs (I have trouble of those situation, I am scared that I will stutter.)
- those learned behaviours and cognitive beliefs lead to stuttering behaviours without a neurological jamming.
- I would not talk about a breaking dam but more like a dripping (a bit like Chinese torture: let water drip on a prisoner for a few hours) that will lead to maladaptive reactions.