underachievement: neurology or psychology?

Neurology is very interesting and is like a painting of reality to me. Especially if it represents reality in detail. Even better are descriptions that move in time like models or machines or those where you can manipulate and see what happens. But that's it. It is not what happens inside the box or is it? If we look at underachievement, is what happens the activity that stops in the brain, or is this an accurate and interesting show of what events you can observe from the outside? It does show that it is imperative to get enough experience in failure not to shut down when it happens. Hmm... Thanks neurologists for this support.