I'm interested in understanding how isolated different parts of the brain are from each-other. I'm trying to understand the way that different sections of the brain work together.

More specifically, I'm interested in whether or not the different sections are all intertwined together into a wild mass, or work in a more isolated way:

Do different specialized areas of the brain have specific, consolidated connection areas where they exchange information (sort of like they do their job and pass on the necessary information to the other modules)?

Or do they instead mesh very thoroughly, connecting freely to other parts of the brain sort of like tangled string, with no obvious points of consolidated interaction?