When functioning normally, the OAA is a navigation system. It judges angles and distances, maps course trajectories, and keeps track of our body’s exact location. But to do this last part, the superior parietal lobe must also produce a boundary line: the border of self, the division between finite “us” and the infinite “not us” that is the rest of the universe. Obviously, drawing this border is no simple task. So the OAA depends on a constant stream of incoming messages. All of our senses send data here. Incredible calculations occur. But all of this takes a lot of energy. When that energy is
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