101 Essays on Infinite Lifespans   Raymond Kurzweil REDESIGNING THE HUMAN BRAIN The process of reverse engineering and redesign will also encompass  the  most  important  system  in  our  bodies:  the brain. The brain is at least as complex as all the other organs put  together,  with  approximately  half  of  our  genetic  code devoted to its design. It is a misconception to regard the brain as a single organ. It is actually an intricate collection of infor- mation  processing  organs,  interconnected  in  an  elaborate hierarchy, as is the accident of our evolutionary history. The process of understanding the principles of operation of the human brain is already well under way. The under- lying technologies of brain scanning and neuron modeling are scaling up exponentially, as is our overall knowledge of human brain function. We already have detailed mathemati- cal models of a couple dozen of the several hundred regions that comprise the human brain. The  age  of  neural  implants  is  also  well  under  way.  We have brain implants based on ‘neuromorphic’ modeling (i.e., reverse engineering of the human brain and nervous system) for a rapidly growing list of brain regions. A friend of mine who became deaf as an adult can now engage in telephone conversations again because of his cochlear implant, a device that interfaces directly with the auditory nervous system. He plans to replace it with a new model with a thousand levels of frequency discrimination, which will enable him to hear music once again. He laments that he has had the same melo- dies playing in his head for the past 15 years and is looking forward to hearing some new tunes. A future generation of cochlear  implants  now  on  the  drawing  board  will  provide levels of frequency discrimination that go significantly beyond that of ‘normal’ hearing.