I'm sorry but books are not going to suffice for the claims you have made. Do you have any references that you can provide me? I'll gladly read them so I can understand your points further. Moreover, there are no studies determining the direct alterations between pre and post synaptic dopamine. We actually can't even do that in humans at all. So I have to be inclined to believe that you made up that pre-synaptic dopamine is high and post-synaptic dopamine is low. "I’d like to clarify that a rewarding stimulus elicits a rise in dopamine rather than dopamine itself producing a pleasurable feeling. If a novel stimulus is deemed rewarding, the resulting spike in synaptic dopamine tends to be prolonged and heightened, facilitating further approach behavior toward the stimulus." All you're talking about is reward prediction error. There are no studies looking at this. Let's grant what you're saying. Why is it that someone can say a word completely fluently, but then when asked to repeat that word, they sometimes stutter? By your logic, that unexpected need to repeat the word would lead to a reduction in dopamine rather than an increase. In addition, as you would know, a key hub of reward prediction error is the nucleus accumbens, an important structure in stuttering, but not as important as others, like the caudate and putamen for instance.