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| Meet your
amazing brain |
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is called the medulla," she explains. "It regulates your
heartbeat and respiration, so it's essential to your life. It's only an inch long in the
human brain, and the same length in a chimpanzee's brain." But the medulla in a human
develops to three times the capacity of the chimp.
"Next to it is the cerebellum. Literally that
means 'little brain'. It's responsible for coordination and balance. And only recently
have we found out how important it is for learning and for speech."
She then holds up the top half of the brain, the part
that looks like a giant wrinkled walnut: the cortex. "If it wasn't folded, it would
be about two and a half feet square." Why is it folded? "Well, we believe it
developed over thousands of centuries. Basically, to go through the human birth canal this
part of the brain had to fold in upon itself." According to many scientists, the
brain developed new capacities as our ancestors came down from the trees, started to walk
upright, learned to use fire, started to use and make tools, and learned to speak.
Says Professor Diamond, the scientist who dissected
part of the late Albert Einstein's brain: "You'll find the most recently-evolved part
of the brain right behind your forehead: your frontal lobe. It's essential for your
personality, for planning ahead, for sequencing ideas. It's this part primarily which
makes modern man differ from his earlier ancestors."
Behind that she points to the area just behind the
forehead. "For me to be talking to you right now, it's this part of my brain that's
firing. We call it our motor speech area. For one to understand the words I'm saying
[pointing to an area further back], this is the part of your brain that would be in
action."
And not surprisingly you don't process sight only
through your eyes. Professor Diamond points to the back of her head. "You'll find
your visual cortex back here. When you're hit on the back of the head, that's why you see
stars. You've jarred your visual cortex."
As she slices through the brain, she explains each
part: the small areas that move your arms, legs and fingers; the parts that control
feeling, pain, temperature, touch, pressure and hearing.
And as she moves down into the limbic system, Professor
Diamond starts delving into even deeper secrets: the parts of the brain that deal with
fear, rage, emotion, sexuality, love, passion. The tiny pituitary gland that secretes
hormones. The ability of the brain to register and cut off pain. And the almost magical
way the brain sends messages around itself and around your body: messages that are
constantly changing from electrical
Contents Page Preface
Introduction
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