People have speculated over the value of meditating for thousands of years. Meditating seems to improve people’s mood, increase their self-awareness, and help them relax. Of course, mere hearsay will not convince neurologists—only empirical investigation will. To that end, a group of researchers headed by the Massachusetts General Hospital (MGH) recently investigated to see if there are any benefits to meditation, finding that persistent meditation can increase gray matter density in the brain.

So, what exactly does that mean? Gray matter is responsible for most of the tasks that involve experiencing the world: gathering sensory data from the body and sending it to where it needs to go. This is in contrast to white matter, which basically sets the speed for how fast sensory data travels throughout the body. Gray matter is like the cargo, and white matter is like the truck.

To investigate whether meditation has any impact on gray matter at all (or any area of the brain in general), the scientists at MGH gathered two groups: a meditation group of 16 people who would meditate for 8 weeks under the auspices of the Mindfulness-Based Stress Reduction (MBSR) Program at the University of Massachusetts Center for Mindfulness, and a control group that would not meditate over the same period of time.

The meditation regiment consisted of weekly meetings with the MBSR and meditation homework, where the meditation group listened to recordings for guided meditation. They were told to journal their time meditating, and on average each person spent 27 minutes a day meditating. Additionally, the MGH took a magnetic resonance image (MRI) of all the participants' brains before and after the eight-week period.

Compared to the control group, the meditation group’s brain structure had changed after the eight-week timeframe. The follow-up MRI revealed denser gray matter in the hippocampus as well as in structures of the brain associated with introspection and compassion, and less dense gray matter in the amygdala, a part of the brain associated with stress and anxiety. The control group experienced none of these changes, suggesting that meditation, indeed, was the x factor.

Interestingly, the meditation group did not show changes in their insula, a part of the brain associated with self-awareness. This either may be because meditation does not change the brain in this regard or because it takes more than eight weeks for changes in the insula to occur.

Astonishing as it sounds, this MGH study appears to have correlated meditation with physical changes in the brain itself. Even if such correlations never appear for the insula, the hippocampus and other regions of the brain undoubtedly saw changes for the better in the meditation group. While this research has obvious implications for psychology and psychiatry, we should remember that meditation techniques arose from religious traditions. Western religions may find reason in this research to reexamine, and perhaps re-engage, their own meditative and contemplative practices.

For more, see “Mindfulness meditation training changes brain structure in 8 weeks” in Physorg.

And see here for the abstract of the original article, "Mindfulness practice leads to increases in regional brain gray matter density," in Psychiatry Research: Neuroimaging.