If the brain is a connected system of interrelated boxes that is in control of the behavior of the body then that would explain why if one thing goes wrong with the brain the whole system doesn't shut down. This also makes it possible to test and observe which part of the brain controls which behavior.
When a person is involved in a car accident in which they suffered severe frontal damage, while the rest of the brain is intact then that still allows for them to be able to breathe (medulla) and carry out the hormonal processes for the body (thalamus). ( Iam not sure if this 100% true but this in a hypothesis.) This lends a lot of hope to the preservation of the brain, if for some reason something should happen to it. These interconnected parts of the brain make it possible for someone to still lead a "normal" in the case of some forms of brain damage.
With these parts of the brain it is very possible to see which part controls the emotions, intelligence, the social situations, etc., of the human body. Experiments could be devised that under special lab conditions allows the scientist to see what part of the brain is active or even if there is a organization of other parts to come up with a response to "stimuli". This information could lead to the knowledge of whether or not the pathway of the nerves are different or if they behave in a certain way in order to fulfill the demand, in the different parts. It would be very convenient to think that the brain does operate in a way that does warrant the independent yet coexisting manner which allows organisms to behave or respond to the situations that if faces on a daily basis
Interconnected boxes does indeed both provide a basis for thinking about recovery from brain damage and for exploring the brain. One does, however, have to keep in mind that the different functions served by the different boxes may be quite different from the different components of behavior one imagines from other forms of exploration. PG