Imagine building a computer that can store a hundred years’ or more worth of information; analyze and seamlessly combine multi-media data—images, sounds, numbers, words, and even sensations and smells; recognize and recall complex patterns; generate its own data from scratch; and even write its own software. Make it able to control complex mechanical, electrical, and chemical processes equivalent to those of a small factory, and make sure it can connect instantly to any of billions of others like it. Make it portable, keep it smaller than a fair-sized grapefruit, keep its weight under about three pounds, make it operate with no battery and no cooling fan, on less power than a twenty-five watt bulb, and you have something like the human brain. Your brain. It’s the most advanced biological structure found anywhere in nature. Have you ever considered what a phenomenal gift you have in this biological computer? Let’s take a closer look at this remarkable system and understand more fully the potential it offers for living more intelligently and joyfully. Referring to Figure 3.1, we see the general physical structure of the brain and spinal cord, which form the central processor and the primary communication axis for the whole extended biocomputer. Although not visible in the simplified diagram, your brain floats inside a shockproof vault—your cranium. Three layers of tough tissue, the meninges, protect it and cushion it from bouncing against your skull. It’s the best-protected organ in your body, and it enjoys the highest priority when blood, oxygen, and nutrients are distributed. It produces and floats in its own cerebro-spinal fluid, which circulates nutrients and flows downward to the body, carrying waste products with it.
Figure 3.1. Architecture of the Brain
Also not shown in the diagram is the whole system of arteries and veins, which supply the brain with blood. The absence of a properly oxygenated blood supply to the brain for longer than about four minutes usually causes irreversible brain damage or death. Your brain consumes about 20 percent of your body’s glucose supply and a similar amount of its oxygen. It burns energy at a rate about equal to a twenty-five-watt bulb. (We’ll fore go the obvious jokes about people whose bulbs are dimmer than others.)
Also not shown in the diagram is the whole system of arteries and veins, which supply the brain with blood. The absence of a properly oxygenated blood supply to the brain for longer than about four minutes usually causes irreversible brain damage or death. Your brain consumes about 20 percent of your body’s glucose supply and a similar amount of its oxygen. It burns energy at a rate about equal to a twenty-five-watt bulb. (We’ll fore go the obvious jokes about people whose bulbs are dimmer than others.)
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