Physicians have long tinkered with ways to "improve" the human brain, but as our understanding of that organ's inner workings quickly grows, artificial enhancement is becoming more feasible. Military research is at the forefront of this work, much of it focused on drugs. The goal is to produce a better soldier, but the emerging techniques could just as easily be applied to any individual.
The military wants to juice up personnel's brains because the human being is the weakest instrument of warfare. Although for centuries astonishing and terrifying advances have been made in the technology of conflict, soldiers are basically the same. They must eat, sleep, discern friend from foe, heal when wounded, and so forth. The first state (or nonstate) actor to build superior fighters will make an enormous leap in the arms race. In the short run, researchers are trying to devise aids that would overcome a person's inherent limitations, such as mental fatigue. Long-term results could lead to individuals everywhere who are tireless, less fearful or even better speakers.