Neuroscience Reveals the Secrets of Meditation’s Benefits
Contemplative practices that extend back thousands of years show a multitude of benefits for both body and mind
Oct 14, 2014 |By Matthieu Ricard, Antoine Lutz and Richard J. Davidson
When the Society for Neuroscience asked Tenzin Gyatso, the 14th Dalai Lama (the leader of Tibetan Buddhism), to address its annual meeting in Washington, D.C., in 2005, a few hundred members among the nearly 35,000 or so attending the meeting petitioned to have the invitation rescinded. A religious leader, they felt, had no place at a scientific meeting. But this particular leader turned out to have a provocative and ultimately productive question to pose to the gathering. “What relation,” he asked, “could there be between Buddhism, an ancient Indian philosophical and spiritual tradition, and modern science?”
The Dalai Lama, putting action before rhetoric, had already started trying to find answers to his own question. Back in the 1980s, he had sparked a dialogue about science and Buddhism, which led to the creation of the Mind & Life Institute, dedicated to studying contemplative science. In 2000 he brought new focus to this endeavor: he launched the subdiscipline of “contemplative neuroscience” by inviting scientists to study the brain activity of expert Buddhist meditators—defined as having more than 10,000 hours of practice.
For nearly 15 years more than 100 monastics and lay practitioners of Buddhism and a large number of beginning meditators have participated in scientific experiments at the University of Wisconsin–Madison and at least 19 other universities. The article you are reading, in fact, is the product of a collaboration between two neuroscientists and a Buddhist monk who originally trained as a cell biologist.
A comparison of the brain scans of meditators with tens of thousands of hours of practice with those of neophytes and nonmeditators has started to explain why this set of techniques for training the mind holds great potential for supplying cognitive and emotional benefits. The goals of meditation, in fact, overlap with many of the objectives of clinical psychology, psychiatry, preventive medicine and education. As suggested by the growing compendium of research, meditation may be effective in treating depression and chronic pain and in cultivating a sense of overall well-being.
The discovery of meditation’s benefits coincides with recent neuroscientific findings showing that the adult brain can still be deeply transformed through experience. These studies show that when we learn how to juggle or play a musical instrument, the brain undergoes changes through a process called neuroplasticity. A brain region that controls the movement of a violinist’s fingers becomes progressively larger with mastery of the instrument. A similar process appears to happen when we meditate. Nothing changes in the surrounding environment, but the meditator regulates mental states to achieve a form of inner enrichment, an experience that affects brain functioning and its physical structure. The evidence amassed from this research has begun to show that meditation can rewire brain circuits to produce salutary effects not just on the mind and the brain but on the entire body.
What Is Meditation?
Meditation has roots in the contemplative practices of nearly every major religion. The prevalence of meditation in the media has given the word various meanings. We will refer to meditation as the cultivation of basic human qualities, such as a more stable and clear mind, emotional balance, a sense of caring mindfulness, even love and compassion—qualities that remain latent as long as one does not make an effort to develop them. It is also a process of familiarization with a more serene and flexible way of being.
In principle, meditation is relatively simple and can be done anywhere. No equipment or workout attire is needed. The meditator begins by assuming a comfortable physical posture, neither too tense nor too lax, and by wishing for self-transformation and a desire for others’ well-being and for the alleviation of their suffering. Later the practitioner must stabilize the mind, which is too often disorderly—and occupied by a stream of inner chatter. Mastering the mind requires freeing it from automatic mental conditioning and inner confusion.
We will examine here what happens in the brain during three common types of meditation developed through Buddhism and now practiced in secular programs in hospitals and schools throughout the world. The first one, focused-attention meditation, aims to tame and center the mind in the present moment while developing the capacity to remain vigilant to distractions. The second one, mindfulness, or open-monitoring meditation, tries to cultivate a less emotionally reactive awareness to emotions, thoughts and sensations occurring in the present moment to prevent them from spiraling out of control and creating mental distress. In mindfulness, the meditator remains attentive, moment by moment, to any experience without focusing on anything specific. Finally, another type of practice is known in Buddhist tradition as compassion and loving kindness and fosters an altruistic perspective toward others.
Under the Scanner
Neuroscientists have now begun to probe what happens inside the brain during the various types of meditation. Wendy Hasenkamp, then at Emory University, and her colleagues used brain imaging to identify the neural networks activated by focused-attention meditation. In the scanner, the participants trained their attention on the sensation produced by breathing. Typically during this form of meditation, the mind wanders from an object, and the meditator must recognize this and then restore attention to the gradual rhythm of the inhaling and exhaling. In this study, the meditator had to signal mind wandering by pressing a button. Researchers identified four phases of a cognitive cycle: an episode of mind wandering, a moment of becoming aware of the distraction, a phase of reorienting attention and a resumption of focused attention.
Each of the four phases involves particular brain networks. The first part of the cycle, when a distraction occurs, increases activity in the wide-ranging default-mode network (DMN). This network includes areas of the medial prefrontal cortex, the posterior cingulate cortex, the precuneus, the inferior parietal lobe and the lateral temporal cortex. The DMN is known to become activated during mind wandering and to play a general role in building and updating internal models of the world based on long-term memories about the self or others.
The second phase, becoming aware of a distraction, occurs in other brain areas such as the anterior insula and the anterior cingulate cortex, regions of what is called the salience network. This network regulates subjectively perceived feelings, which might, for instance, lead to being distracted during a task. The salience network is thought to play a key role in detecting novel events and in switching activity during meditation among assemblies of neurons that make up the brain’s large-scale networks. It may shift attention away from the default-mode network, for instance.
The third phase engages additional areas—among them the dorsolateral prefrontal cortex and the lateral inferior parietal lobe—that “take back” one’s attention by detaching it from any distracting stimulus. Finally, in the fourth and last phase, the dorsolateral prefrontal cortex continues to retain a high level of activity, as the meditator’s attention remains directed toward an object such as the breath.
In our laboratory at Wisconsin, we further observed different patterns of activity depending on a practitioner’s level of experience. Veteran meditators with more than 10,000 hours of practice showed more activity in these attention-related brain regions compared with novices. Paradoxically, the most experienced meditators demonstrated less activation than the ones without as much experience. Advanced meditators appear to acquire a level of skill that enables them to achieve a focused state of mind with less effort. These effects resemble the skill of expert musicians and athletes capable of immersing themselves in the “flow” of their performances with a minimal sense of effortful control.
To study the impact of focused-attention meditation, we also studied its volunteers before and after a three-month retreat with intensive meditation exercises for at least eight hours a day. They received headphones that broadcast sounds at a given frequency, occasionally mixed with slightly higher-pitched sounds. They had to focus on the sounds played in one ear for 10 minutes and react to periodically interspersed high-pitched tones. After the retreat, we found that meditators, compared with a nonmeditating control group, showed less trial-to-trial variation in their reaction times on this highly repetitive task, which lent itself easily to distractions. The result suggested that the meditators had an enhanced capacity to remain vigilant. The brain’s electrical responses to high-pitched tones remained more stable at the second session only for the meditators.
Stream of Consciousness
The second type of well-studied meditation also involves another form of attention. Mindfulness, or open-monitoring meditation, requires the meditator to take note of every sight or sound and track internal bodily sensations and inner self-talk. The person stays aware of what is happening without becoming overly preoccupied with any single perception or thought, returning to this detached focus each time the mind strays. As awareness of what is happening in one’s surroundings grows, normal daily irritants—an angry colleague at work, a worried child at home—become less disruptive, and a sense of psychological well-being develops.