“If a more complicated entity than the human brain exists on Earth, it has succeeded in maintaining its confidential nature. Not only is the brain the most multifaceted organ in the human body, and composed of the greatest number of diverse cell types in a single organ, it is also the most adaptable and complex single object in the known universe.
Prior to the 1990s, most information gathered about the human brain came largely by way of misfortune—brain-injured patients or disease. The balance of our knowledge was speculative or intelligent deductive conclusions. Brain injuries and postoperative behavior changes gave us a peek into the nature of processes such as movement, memory and language.”