How Meditation Reshapes Your Brain

Written by Max Miller on BIG THINK.

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.

Using this electroencephalograph technology, Davidson asked his monks, each with 10,000 to 50,000 hours of meditation practice over their lifetimes, to concentrate on "unconditional loving-kindness and compassion." A group of inexperienced meditators were also trained for one-week and then instructed to do the same. The results were dramatic, revealing two important things: first, the monks exhibited a higher ratio of high frequency gamma brainwaves to slower alpha and beta waves during their resting baseline before the experiment began; and when the monks engaged in meditation, this ratio skyrocketed—up to 30 times stronger than that of the non-meditators. In fact, the gamma activity measured in some of the practitioners was the highest ever reported in a non-pathological context. Not only did this suggest that long-term mental training could alter brain activity, it also suggested that compassion might be something that could be cultivated.

New neurobiological research bolsters the idea that meditation effects a permanent restructuring of the brain. In 2008 a team of researchers from UCLA led by Eileen Luders compared the brains of long-term meditators with those of control subjects. In the brains of the meditators, they found larger volumes of gray matter in the right orbito-frontal cortex and the right hippocampus, areas thought to be implicated in emotion and response control. "It is likely that the observed larger hippocampal volumes may account for meditators' singular abilities and habits to cultivate positive emotions, retain emotional stability, and engage in mindful behavior," Luders writes. They also discovered a marked increase of gray matter in the thalamus, which is thought to act as the brain's switchboard, relaying information between the cerebral cortex and subcortical areas. The change in size might allow for the meditators' enhanced sense of focus during their practice.

And it turns out, you don't have to be a yogi to reap the benefits of meditation. Even those who participate in short-term training courses can alter their brains, according to research published this summer: In a collaborative study between the University of Oregon and the Dalian University of Technology in China, neuroscientists discovered that a Chinese meditation technique called integrative body-mind training (IBMT) could alter the connectivity in the brain after just 11 hours of practice. Using a type of magnetic resonance called "diffusion tensor imaging," the researchers examined the white matter fibers connecting different brain regions before and after training. The changes were most dramatic in the anterior cingulate, an area implicated in emotion control.

Types of Brain Waves

The frequency of brainwaves varies among different mental states, indicating the amount of neuronal activity in the brain. Delta waves (below 4 Hz) are the longest waves and occur mostly during deep sleep. Theta waves (5-8 Hz) are seen most commonly in young children and in drowsy adults, often as an entree to sleep. Alpha waves (8-12 Hz) are the waves of an relaxed, non-aroused mind. Beta waves (12-30 Hz) are fast and low amplitude and are characteristics of an engaged mind. And finally gamma waves (30-100 Hz) are the highest in frequency and are thought to represent the synchronization of different brain areas as they carry out certain cognitive or motor functions. It is important to realize that the brain never produces just one type of these brain waves; they all occur simultaneously, but their ratios will change depending on one's mental state.


Takeaway

Far from being simply a relaxed state, meditation is a period of heightened activity in the brain—one that can actually reshape your brain. People as diverse as David Lynch and the Dalai Lama have touted the benefits of meditation, claiming that it can increase attention, combat stress, foster compassion, and boost health. And in the past two decades, neuroscientists have begun to understand the biological substrates of these claims. Research suggests that long-term meditation increases the orbitofrontal cortex, the hippocampus, and the thalamus, potentially increasing one's capacity for attention as well as compassion.