First, it is obviously important for us to understand how the brain works for various reasons, from pure curiosity to various potential applications. Second, brain science can serve as a good example of the interdisciplinary approach whose importance in the study of various complex systems in both science and engineering has been widely realized. Most of the scientific frontiers have been pushed far away from our everyday experience. However, this is not the case in the study of our own brain, which is so closely related to our everyday life, but still so little known. At present, no one in the world can give a definite answer to any of these questions.
Brain science seems to be still in a relatively primitive stage compared to many other sciences.
However, in the last several decades, tremendous efforts have been made towards the understanding of various aspects of the brain and major progresses have been made. Some people predict that the next scientific breakthrough in the 21 century will be from brain science, just as those breakthroughs in this century, such as relativity theory, quantum theory, and the discovery of the DNA structure. One major reason why brain science does not seem to be as advanced as other sciences is the complexity of the brain. In the human brain there are about 100 billions neurons each linked to many others by hundreds or thousands synaptic connections. It is pretty obvious that either or both of these methods won't be enough for us to understand how the computer works.