It's time for the human brain to look to the future, but what will that future be? There's a lot of updating going on already. The brain is making bigger news than genes, which wasn't so twenty years ago. The standard model of the brain was a stable, porridgy gray mass that couldn't heal itself or even grow new brain cells. A standard way to warn about the damage done by alcohol was to point out how many million brain cells were killed off by heavy drinking, cells that would never be replaced. But this old brain model has proved to be either wrong or incomplete.
The latest model reverses most of the accepted beliefs from the past. We now see the brain as dynamic, not fixed. Its processes are so "soft-wired" that new pathways are formed by everyday behavior, habits, and conditioning. Stem cells exist in the brain, allowing for newborn neurons at every stage of life. And the injured brain can regenerate and heal itself, shifting a lost function to a new, undamaged area of itself. None of these things are disputed anymore. Everyone in the field is excited about the next big breakthroughs in neurology, whatever they may be.
My bet is on quantum biology, which hopes to link the brain as we know it to a completely new world, where physics has defined reality in terms of uncertainty, wave and particle duality, and relativity. "Quantum" has become a cliché, but not when it comes to the brain, because only in the quantum field can we hope to unravel the brain's most profound mysteries, such as where thoughts come from and why we are conscious in the first place. Let me outline a few basics so that the next revolution won't come as a shock -- lots of work on the quantum brain has already been done, and it's stirring up considerable controversy.
Right now, if you want to explain how the brain thinks, the ruling theory comes from computer science. It seems like a natural fit. Computers process information, and so does the brain. Digital language is based on two letters (0 and 1), while neurons use positive and negative, the opposite charges of chemical ions. Computers have hardware and software, which seems to fit the brain's billions of neurons (the hardware) that support language, sensations, memories, and so on (the software). Because we know a great deal more about computers than we do about the brain, science finds itself in a strange reversal. Instead of looking at the brain to tell us how computers work, it uses computers to teach the brain how it is functioning.
Quantum biology doesn't agree with this approach. The noted British physicist Roger Penrose started tearing down the accepted explanations when he declared that the brain can't be reduced to mechanical formulas. There is no mathematics that can infallibly program a brain cell. Penrose didn't mean that the math got too complex, even though the brain's hundred billion neurons would certainly need a mammoth supercomputer to be duplicated. Penrose had a far more crushing point to make. The brain is working through quantum calculations, he said, because until a brain cell picks which process to favor, both choices exist simultaneously. Such "indeterminacy" has long existed in the way physics explains the nature of light, which can be either a particle or a wave in its behavior. Until a photon "decides" which way to behave, the possibility of wave and particle exist together.
I know this sounds complicated, but consider your own thoughts. At any given moment you don't know what your next thought will be. Thoughts come out of the blue, and yet once they arrive, they are definite. You can't think "blue" and "red" at the same instant. It's one or the other. Yet before you make that choice, both colors are possibilities. This example simplifies the argument, but it doesn't falsify it. When you get down to the smallest structures in the brain, the so-called microtubules that allow only one ion of sodium to pass through them (like a fat person who can barely make it through the door), simple pictures won't work. You must envision thousands of potential ions waiting to carry "blue," and thousands waiting to carry "red" they are poised to jump on stage, but until that happens, both sets of ions must wait offstage in the wings.
How can two complete sets of ions occupy a tiny space that barely holds one? They can't, which is why Penrose's argument for a quantum brain has proved powerful, if highly controversial. Only if the two sets of ions are in a quantum state -- that is, existing as shadows of possibility -- can we explain how a single thought emerges from two potential thoughts. Of course, there are a lot more colors than red and blue, and a lot more thoughts than thinking about colors -- an infinite number of potential thoughts. Once you see the logic, you realize that the computer=brain equation never worked very well. Computers are capable of infinite computations, but they are all based on a set program. The brain is unpredictable and therefore creative. (If one scene of a Shakespeare play was absent, no computer could write a genuine replacement, but Shakespeare himself would have no trouble.)
There's a lot more to be said about the brain's future, but here is an intriguing insight. Experimenters working with rats have discovered the pleasure centers in their brains. When this center is stimulated, the rat is "happy." There is no need for a more complex explanation. If you feed a rat, its pleasure center lights up. But to add a twist, if you put the rat near its feed bowl or fill its cage with the smell of food, the pleasure center will light up in expectation of eating. So the rat can be happy even before the food shows up. Human beings can relate. When we think about taking a beach vacation next summer, our pleasure centers light up as well (in fact, one key to happiness, we are told, is to plan long-range pleasures like vacations rather than short-range ones like a candy bar ten minutes from now. The short range pleasure has no lasting effect, while planning a vacation can keep you in a pleasant state for months.)
Human beings cannot be made happy by pleasure, however. We have a quality known as perverseness. Someone can offer you your favorite chocolate, and instead of having your brain light up like a rat's, you can say no. Maybe you are mad at that person or depressed about your life. Maybe you are bored with chocolate, or just maybe you are feeling perverse. Computers are incapable of perversity. If you program them a certain way, they won't do the reverse, they won't be arbitrary or fickle, and most important of all, they won't balance yes and no as equal possibilities at the same time.
Perversity, it turns out, has a hidden genius inside. We feel free to think and act any way we want. That's obvious to anyone who has dealt with a young child going through the terrible twos, a teenager, or the state of falling in love. It irks computer scientists that these anomalies mar their mathematical model, but these are not anomalies. Being free to do whatever you want is what makes us human. No machine can duplicate such a state, and according to quantum biology, the reason is rooted in the indeterminacy of the quantum state. Indeed, we may be too creative to fit inside our brains. The prospect of eliminating the brain and going directly to the infinite field of consciousness, a field that permeates the entire universe, is looming larger and larger.
(To be cont.)