Meditation doesn't only affect the brain while you're meditating. This may not be news to people who meditate. They often report that the practice provides long-lasting benefits. But a new study finds that simply learning how to meditate creates physical changes that can be seen and measured during the brain's everyday activities. It also found that different types of meditation training seem to produce different subtle, but noticeable, beneficial changes in the human brain.

Like other research probing the science behind meditation, this study suggests that meditation is a lot more than a one-size-fits-all treatment for a few mental woes; it's a much more versatile tool for fine-tuning the human mind.

Two different types of meditation, two different types of changes seen in the brain.

The study looked at the effects of teaching two different forms of meditation to healthy adults at Emory University in Atlanta. One group of adults learned mindful attention meditation, a type of mindfulness meditation that focuses on breathing, thoughts and emotions. One aspect of mindful attention meditation is to get people to take the stress and unpleasantness that occur in their lives more in stride than they have been doing and to be less overwhelmed by it.

The other group learned compassion meditation, a type of meditation that seeks to increase a person's compassion for oneself and others.

Participants received eight weeks of training and were flown to Boston for brains scans (fMRI) twice -- three weeks before starting their training and three weeks after completing their training. During these scans, participants, who were not meditating, were shown 108 different images of people in varying emotional situations--from happy to neutral to sad.

Which type of meditation the people had learned dictated how they reacted to these images. And the differences could be seen in the subjects' amygdala, an area of the brain known to be intimately involved in emotion and memory.

There were two very obvious differences seen in the right amygdala of participants. In the people who learned mindful attention meditation, there was a decreased activity towards all images seen after their meditation training. Whether the images were of happy, sad or neutral people, the right amygdala of mindful attention trainees reacted less strongly to these images after their training. This is what you'd expect from training that succeeds at getting people to react less strongly to all the slings and arrows that the world throws at them.

But in the compassion training group, those who reported practicing compassion meditation most frequently outside the lab showed the strongest activation of the right amygdala in response to sad images, all of which showed people suffering. Once again, an indication that the training was effective, this time at increasing compassion.

Two different types of meditation, two different types of changes seen in the brain.

This isn't the first study to show that meditation can cause physical changes in the brain. The pain resistance shown by experienced Zen meditators is accompanied by a noticeable thickening in the anterior cingulate cortex of the meditator's brain. And people who took a mindfulness based stress reduction (MBSR) course showed both an increase in the amount of grey matter in their hippocampus and a decrease in the amount of grey matter in their amygdala. But the current study may well be the first one to characterize multiple changes caused by multiple schools of meditation.

With all the studies that are currently trying to link benefits of meditation to changes in specific regions of the brain, it can be easy to forget just how many different ills and woes meditation can help people overcome. From pain relief that rivals morphine to simply helping relieve feelings of loneliness, it's this versatility that may ultimately prove to be meditation's most impressive quality.

An article on the study appears in Frontiers in Human Neuroscience .