The brain, particularly in sensory perception and thought circuits, is initially crudely wired and undergoes progressive pruning and strengthening of connections during development, leading to directed action and thought.

“The other idea would be-- and we know this as a fact, which is that, initially, the brain is fairly crudely wired. That's not true within the neural circuits that control breathing, heart rate, et cetera, but within the neural circuits of sensory perception, thought, et cetera. They're fairly crudely wired. And then across development, there's a progressive pruning back and also in parallel to that, a strengthening of the connections that underlie directed action and thought.”