The last frontier, in my opinion, is the brain and the study of human consciousness. In many spiritual practices the area between the navel and the, well you know what, is thought to be the place to center yourself. It seems it's where advanced martial artists go. It is probably related to meditation practices and stuff like Kundalini or whatever that is. As Croton mentioned we have two independent brains in our head which may or may not know what's going on in the other. I remember an experience I had where I happened to be looking at a light bulb while I was thinking through some train of thought more or less autonomically and the ideas turned unpleasent. They awoke some unpleasant memory is my guess. The light bulb jumped position (my awareness of it shifted from one eye being dominate to the other eye being dominant) and at that instant I found myself deep in the middle of a completely different stream of thought I had been completely unaware I was even thinking. Hay I'm hungry, I gotta go.