In the journals: Mindfulness meditation practice changes the brain

Mindfulness meditation alters regions of the brain associated with memory, awareness of self, and compassion, according to a brain imaging study by researchers at Massachusetts General Hospital in Boston and the University of Massachusetts Medical School in Worcester. Other studies have found differences in the brains of experienced meditators compared with non-meditators, but this is the first investigation to document brain changes occurring over time in people learning how to meditate mindfully. Results were published in Psychiatry Research: Neuroimaging (Jan. 30, 2011).

Mindfulness meditation is the practice of paying attention to what you're experiencing from moment to moment without drifting into thoughts about the past or concerns about the future and without analyzing (or making judgments about) what is going on around you. It's not a new idea. Religious texts have extolled mindfulness for centuries, and it's central to Buddhism and other contemplative traditions.

Since the early 1980s, mindfulness meditation has increasingly found a place in mainstream health care and medicine because of evidence that it's good for emotional and physical health — for example, helping to reduce anxiety, stress, depression, chronic pain, psoriasis, headache, high blood pressure, and high cholesterol. Some studies suggest that it can improve immune function. And research has found an association between mindfulness meditation–induced improvements in psychological well-being and increased activity of telomerase, an enzyme important to the long-term health of cells. With advances in neuroimaging, scientists have begun to explore the brain mechanisms that may underlie these benefits.

The study. Researchers recruited 16 participants from the eight-week Mindfulness-Based Stress Reduction program at the University of Massachusetts Medical School's Center for Mindfulness. The participants attended weekly 2.5-hour group meetings in which they practiced mindfulness meditation and were given audio recordings of guided meditation exercises and told to practice daily at home. Before the start of the program and after its completion, researchers took MRI images of the meditators' brains as well as the brains of 17 non-meditators, who served as a control group.

The results. On average, the meditators spent about one half-hour a day meditating during the eight-week course. Questionnaire responses indicated that at the end of the eight weeks, they felt more capable of acting with awareness, observing, and remaining nonjudgmental. The MRI images showed that the meditators (but not the controls) had increased concentrations of gray matter (the "computing" or processing neurons) in several brain areas, including the hippocampus (a deep brain structure important for learning, memory, and the regulation of emotions) and other regions associated with remembering the past and imagining the future, as well as with introspection, empathy, and the ability to acknowledge the viewpoints of others. The authors suggested that these changes may be beneficial because of their impact on the synthesis of neurotransmitters (particularly serotonin and norepinephrine) that influence mood. In an earlier study of the same participants, the researchers had found that meditation practice reduced the concentration of gray matter in the amygdala, a region associated with fear, anxiety, and stress — and that this reduction was correlated with lower stress levels.

Limitations and implications. Although this study was well designed, it's not likely to be the last word on the subject. It was small, and the significance of changes in grey matter concentration isn't entirely clear. Also, brain changes were not correlated with the amount of time a meditator spent practicing, so other factors may play a role. Nonetheless, these findings suggest directions for research. We already know that learning new physical skills (such as juggling) can change the brain; this study offers intriguing new evidence that learning to think in a new way can do the same.