In the 1990s, scientists knew so little about the brain that their estimates of its unwrinkled size ranged from “dinner napkin” to “tennis court”. Today, we can identify which parts of the brain activate when you take drugs, fall in love, find God, and get a joke in the Simpsons. But we don’t know what causes depression, the second most disabling disease in the world. Our most powerful antidepressant is still electroshock therapy: it works in 8 out of 10 cases, but we don’t understand why.
It’s cold and you’re naked, lying inside what sounds like a giant washing machine. It’s too dark to see, but surrounding your head is an enormous magnet. It is strong enough to pick up a car, but right now it is pointed at something smaller and much more personal: your brain.
Functional Magnetic Resonance Imaging (fMRI) is 20 years old, but what it does is still astonishing: it takes pictures of your thoughts. It’s not science fiction – if you are shown, say, an image of a dog, certain parts of your brain flash into life and suddenly demand oxygen-rich blood so that they can “think.” If your hand gets burned, the oxygenated blood flows elsewhere. Every thought activates a unique combination of places in your brain, and demands blood in those places. By following the blood, fMRI scanners can map your mind.
“Any kind of emotion is represented in the brain, including happiness”
Richard Davidson, Professor of Psychology, University of Wisconsin, Madison, Wisconsin, USA
The science goes something like this: 60 percent of your body is made up of hydrogen atoms, and the centers of those atoms are magnetic. When the fMRI machine is switched on, its magnet pulls all the hydrogen atoms in your brain in one direction, and then, when it is turned off, it releases them. Whether the hydrogen atom is in oxygenated blood, or your bones, brain or eyeballs, determines the speed that it falls back into its normal position. The movement of these hydrogen atoms is unbelievably small, but the fMRI scanner picks them up with a kind of radar, isolates the bloody bits, and takes a snapshot of your thought processes.
“Any kind of emotion is represented in the brain,” explains Richard Davidson, professor of Psychology at the University of Wisconsin, USA, “including happiness.” And when it came to finding participants to study for happiness, Davidson didn’t take a random sample of people. He used a dozen Buddhist monks. Before laying them down inside his US$2 million fMRI machine, he asked them, once they were inside, to do what they do best: meditate and stay still.
While it is claimed that meditation can train our brains to increase self-esteem, empathy and trust, improve memory, intelligence and creativity, and cure depression, skin disorders, anxiety and substance abuse, how it actually works is little understood. Recently, however, it has been found that the power of thought alone can change the shape and structure of our brains. Psychiatrist Andrea DiMartini found that people who have had violent hallucinations wake up with post-traumatic stress disorder, their brains restructured by the power of their imagination. There’s no obvious reason why this shouldn’t work the other way around, to make people happier. “We work out at the gym to stay healthy,” says Matthieu Ricard, one of the monks tested by Davidson, “we should spend the same effort cultivating basic human qualities, such as inner peace, inner freedom and loving kindness.” Together, he says, that can bring about genuine happiness.
So what was found in the minds of the monks? Taken together, the fMRI scans showed that the more experienced meditators had higher levels of brain activity than the novices, suggesting that a lifetime of meditation may have made them more active. All that extra activity was concentrated in the brain’s left prefrontal cortex, too, the same part of the brain that lights up when people feel happy and caring or see pictures of smiling, healthy babies. Beyond that, though, it was hard to say anything for sure. While fMRI scanners have been churning out beautiful maps of the brain for 20 years, no one really knows how to read them.