Knowledge of exactly how the brain works will change everything. Despite all our technical advances in brain-mapping, we still do not fully understand how the human or nonhuman brain works as a complete organ—e.g., the interconnectedness of the separate areas we are currently mapping. Just as we are beginning to learn that it is not "the" gene that controls what happens in our bodies, but rather the interplay of many genes, proteins, and environmental influences that turn genes on and off, we will learn how the interplay of various neural tissues, the chemicals in our body, environmental influences, and possibly some current unknowns, come together to affect how the brain works…and that will change everything.
We will, for example:
(a) ameliorate diseases in which the brain stops working properly—from diseases involving cognitive deficits such as Alzheimers to those involving issues of physical control such as Parkinsons. We will monitor just when the brain stops functioning optimally and begin interventions much earlier. Age-related senility, with its concomitant problems and societal costs, will cease to exist. If dysfunctions such as autism and schizophrenia are indeed the result of faulty interconnections among many disparate areas, we will 'rewire' the appropriate systems either physically or through targeted drug intervention….similarly for problems such as dyslexia and ADHD;
(b) understand and repair brains susceptible to addictions, or criminality that is based on lack of inhibitory control;
(b) use this knowledge to develop models of brain function for advanced robotics and computers to design 'smart' interactive systems for, e.g., space and ocean exploration or seamless interfaces for, e.g., artificial limbs, vision, and hearing;
(c) determine ways in which human and nonhuman brains function similarly and differently, whether human and nonhuman intelligences are distinctly separate or whether a measureable gradient exists, the extent of any overlap of function, and whether the critical issues involve modules or a constellation of inter-functioning areas that both match and are disparate. For example, we will better understand how human intelligence and language evolved and the extent to which parallel intelligence and communication evolved in nonmammalian evolutionary lines. And how they may still be evolving….
(d) maybe frighteningly, attempt to improve upon the current human brain in an anatomical sense, or, in a much more acceptable manner, determine what forms of teaching and training enable learning to proceed most rapidly, by enhancing appropriate connectivity and memory formation. Different types of intelligence will likely be found to be correlated with particular brain organizational patterns; thus we will identify geniuses of particular sorts more readily and cultivate their abilities.
By truly understanding brain function, and harnessing it most effectively, we will affect everything else in the universe—for better or worse.