Meditation Improves Cognition, Studies Show

Researcher presents brain imagery evidence that meditation and yoga improve cognition at AAAS event.

When Sara Lazar was in graduate school, she attended a yoga class because a physical therapist she had visited for knee and back pain said she needed to stretch. As a Ph.D. student in molecular biology, she had no expectation that the class would do anything except maybe get her back in training for a marathon.

“At that point, I equated yoga with power pyramids and tin-foil hats,” said Lazar, associate researcher in the psychiatry department at Massachusetts General Hospital and an assistant professor in psychology at Harvard Medical School. When the yoga teacher would claim that certain poses provided health benefits, Lazar said she rolled her eyes.

After three or four weeks, however, Lazar noticed dramatic changes in how she felt mentally. “I was calmer. I was less reactive,” said Lazar, who spoke at a September 28 Neuroscience & Society event co-sponsored by the American Association for the Advancement of Science and the Dana Foundation. “It was clear to me that it was the yoga practice.”

AAAS and the Dana Foundation have collaborated on the Neuroscience & Society lecture series since 2012, with twenty events so far reaching 3400 attendees. The purpose of the series is to provide a public forum for experts to share the latest advances in brain research and what they might mean for individuals and society.

After Lazar’s experience with yoga, she finished her Ph.D. and switched as a post-doc to researching whether, and if so how, meditation and yoga can change your brain.

Yoga and meditation can affect the brain's structure and function, according to a researcher at a AAAS-Dana Foundation Neuroscience & Society event. | Michael Madd/Flickr (CC BY-NC-ND 2.0)

The first study Lazar and her colleagues undertook involved regular practitioners of meditation and those who did not meditate. The two groups were demographically matched for gender, race, age and education.

The study, using scans of the subjects’ brains, showed that the meditators had more gray matter, which equates with more neuronal activity and better performance, in certain areas. The insula, which is associated with the integration of thoughts, senses and emotions, was thicker in gray matter in the meditation practitioners. So was the prefrontal cortex, which handles working memory and fluid intelligence, or IQ. In her presentation, Lazar pointed out that other studies have shown that people who have practiced meditation long-term have higher IQs than non-meditators.

A question that arose in response to the study, however, was whether the brains of people who meditated were different for other reasons. For instance, was the diet of people who meditated different? The next challenge was to see if it was possible to show, not only differences in brain matter between meditators and non-meditators, but to document actual changes associated with meditation activity.

For this challenge, Lazar and her team recruited study subjects from the Center for Mindfulness at the University of Massachusetts Medical School. The researchers used magnetic resonance imaging (MRI) to scan the brains of the participants before and after they took an eight-week class called Mindfulness-Based Stress Reduction. People who were on a wait-list for the class served as a control group, having their brains scanned at the same times as those who took the class.

According to Lazar, several regions of the brains of the subjects who took the class showed increases in gray matter that did not occur in the control group. The posterior cingulate, an area associated with focus, showed changes. The temporo-parietal junction, an area associated with empathy and compassion, also changed over the eight weeks. And the area of the cerebellum into the brainstem changed, a modification that is associated with well-being. The hippocampus, which is smaller in people who have experienced trauma, showed an increase in size. 

At the same time, the amygdala, which is associated with anxiety, decreased in size, even though the subjects were still experiencing stress in their lives.

“There was nothing about their environment that was changing. All of them still had their crazy boss, still had the relatives that drove them nuts, their commute,” said Lazar. “Nothing had changed except for their amygdala. So, what we’re seeing is the amygdala is responding, not to the actual environment, but to your response to the environment.” 

Meanwhile, Lazar’s lab has also looked at the effect of yoga and meditation on aging. In a study involving yoga practitioners, meditators and controls who did no yoga or meditation, the yogis and meditators had preserved the thickness in the prefrontal cortex and insula, two areas of the brain that usually decrease with age, causing a loss of fluid intelligence.

“This really suggests that meditation may have a bit of an anti-aging effect,” Lazar said. “It may protect our brains from the normal effects of aging.”

Lazar summed up her presentation with a nod to the research question she embarked upon when she first started her research. “My take-home message,” she said, “is meditation can really change your brain.”

[Associated Image Credit: Joffers951/Wikimedia Commons (CC BY-SA-4.0)]