In 2006, filmmaker David Lynch—a poet of the sublimely bizarre and the surreally normal—wrote a book on transcendental meditation. Describing his experience, he writes: "It takes you to an ocean of pure consciousness, pure knowingness. But it's familiar; it's you. And right away a sense of happiness emerges—not a goofball happiness, but a thick beauty."

Coming from the man behind disturbing mindbenders like "Eraserhead" and "Blue Velvet," it's hard to take this statement seriously. But Lynch is indeed being sincere; he has reportedly meditated for 20 minutes twice a day since the 1970s. And his belief in the power of this age-old practice is shared with an estimated 20 million people in the United States alone who engage some form of meditation.

Sharon Gannon, the co-founder of Jivamukti Yoga, the largest yoga center in the U.S., tells Big Think that meditation is all about ignoring stimuli. "We're so habituated to reacting to every stimulus," she says. If the phone rings, we answer it; if someone knocks at the door, we open it. But meditation is a space where we don't react to the stimuli that constantly bombard us; it is about letting go, and it paradoxically makes us better able to engage. "Without taking the time every day to let things come and let things go without acting upon it, you won't have clarity of mind," she says.

But what is actually happening in the brain as we seek nirvana? Meditators have long described their experiences as transformative states that are markedly different from normal consciousness, but only recently have researchers found the evidence to back this up.

Richard Davidson is one of the foremost researchers of meditation's effects on the brain. A Harvard Ph.D graduate and a friend of the Dalai Lama, he was chided early in his career for wanting to study something as unscientific as meditation. But in 2004 he became an overnight scientific celebrity for discovering that Buddhist monks exhibit vastly different brainwaves during meditation than normal people. Brainwaves are produced as the billions of neurons in our brains transmit action potentials down their axons to the synapses where they trigger the release of neurotransmitters. These action potentials are essentially electrical charges that are passed from neuron to neuron. By placing sensors on the scalp, researchers can detect not the individual firings of neurons—they are far too small and numerous to differentiate—but the sum total of this electrical activity, dubbed brainwaves for their cyclical nature.