The study of the human brain, its capacities, and its diseases remains one of the greatest scientific and philosophical challenges ever undertaken. That said, compiling this report to consider aspects of what has been learned and is being learned about the brain that can be useful to the operations of the U.S. Army has also proven to be extremely challenging. First, the field of neuroscience is so dynamic that significant new findings are being announced almost daily. The ability to define the systems of neurons that are activated as a human learns, practices, and performs mental tasks has allowed impressive integration of the constantly accruing understanding of how neurons use their genes to create proteins that enable them to function together. The ability to correlate brain images with function and behavior has already translated into accelerated programs to develop yet more advanced imaging tools and techniques.