The brain is of great interest to scientist because is it the central control center of the nervous system. The nervous system is responsible for the perceiving and converting environment stimuli, interpreting the stimuli and giving commands to the body in response.
The brain is so important to the humans because, without it, humans would be unable to make decisions based on environmental stimuli. Without the brain, coordination of tasks, reasoning, self control, and abstracting thoughts, would also be impossible tasks.