Thinking about thinking
In a class aptly named "gross anatomy," during her first few weeks of medical school, Shannon Moffett got her first good look at a human brain. She was dissecting a cadaver and remembers that the dead brain was murky brown, and "firm, like a block of cheese."
That's far different from the pink, lucent organ in the living body. "Imagine being a neurosurgeon," she writes in her new book, The Three-Pound Enigma (Algonquin Books). "There you are, staring at the slick white surface of [skull]...knowing that just inside, right up against the wall of that box, is the very self of your patient, embodied in a structure as delicate as custard." Thoughts, memories, behavior, and personality are in there somewhere, contained in 3 pounds of exquisitely connected cells poised in a bony bowl at the top of your neck.
But exactly where in those few pounds of flesh do those thoughts and memories lie, and how do they lie there? Moffett wondered. So she took time off from medical school to write a book and find out. By talking to top scientists and doctors who share her fascination, she explores such mysteries as the way memories form, what dreams are made of (and why dreaming about video games seems to make people better at playing them), and why certain people seem to have a "Jennifer Aniston neuron."
What is so interesting, and enigmatic, about the brain?
I think there is absolutely nothing more fascinating than this thing that, after all, contains our ability to be fascinated. It's really easy to say, "It makes us think and move." But when you start to dissect it, you run up against a wall of confusion. How does anybody know a thumbs-up is a positive sign? How do molecules race around in there to make us think? And presumably, if we could better understand what makes us behave and think, we might have a slightly better society. At least that's my utopian hope.
Can we understand what makes us behave and think?
Oh, the brain is such a vast, unexplored territory. But now we're getting these little encampments of knowledge around it. With new brain scans like PET [positron emission tomography] and fMRI [functional magnetic resonance imaging], we are starting to understand where in the brain certain tasks occur.
Like consciousness?
I said "starting" to understand. Consciousness is pretty big; there are some scientists who think it's too big to even ask questions about it. But there are other scientists, like Christof Koch of Caltech, who are using brain-scanning techniques to find single neurons that appear to be "conscious" of particular things.
So you start off with a huge question like 'What is consciousness?' and you end up with one single neuron? That's hard to believe.
Well, the late Francis Crick—the codiscoverer of DNA's structure who later worked with Koch—would say that the biggest questions need to be grounded in the smallest pieces. I talked to him for this book, and that's how he and James Watson went about understanding DNA and won the Nobel Prize for it. In this case, the brain, the smallest piece is a neuron.
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