Leading scientists from Harvard University, Yale University, Massachusetts Institute of Technology, the Mind/Body Medical Institute and other organizations have found the first structural evidence relating meditation practice to changes in the brain. According to a study published in the November 28 issue of Neuroreport (2005; 16 [17], 1893–97), regular practice of meditation correlates with increased thickness in a number of corticol regions associated with sensory, cognitive and emotional processing. Investigators believe that regular meditation practice may also slow age-related thinning of the frontal cortex.

Researchers used magnetic resonance imaging [MRI] to analyze the thickness of the cerebral cortex in 20 experienced practitioners of Buddhist insight meditation and 15 control participants. Insight meditation—also referred to as “mindful meditation”—involves cultivating a present-state awareness of the mind’s activity without judgment or elaboration. The intent is simply to observe the mind and requires highly focused concentration.

Study subjects were not monks. They were Western practitioners who incorporated their practice into busy lives involving careers, families, friends and outside interests. Two were full-time meditation teachers, three were part-time yoga or meditation teachers, and the others meditated an average of once a day for 40 minutes. All had participated in at least one weeklong meditation retreat. The control group consisted of 15 participants with no meditation or yoga experience.

In reaching their conclusion, the study authors speculated that “other forms of yoga and meditation will likely have a similar impact on cortical structure, although each tradition would be expected to have a slightly different pattern of cortical thickening based on specific mental exercises involved.”

This study is significant for collecting the first tangible evidence of actual changes in brain structure associated with meditation. Similar to the way in which we can observe changes in our muscle tone and size as a result of physical exercise, we are beginning to be able to observe and measure changes in the size of brain tissue as a result of meditation. Much more research is needed to study larger numbers of participants and to observe how these changes develop over time.