New study measures meditation's lasting emotional response in the mind

Over-activation by the amygdala has been known to affect everyone from war veterans with PTSD to children with anxiety disorders, and those who buy Effexor to treat depression or anxiety are often dealing with stress caused by this area in the brain. However, complementary and alternative medicine (CAM) such as meditation may be a possible supplement for those looking to nurture their mental health. In the United States, more than 20 million people, or 9.4 percent of the population, had used meditation to boost their health as of 2007, according to a national government survey about CAM.

While past medical studies have provided evidence that meditation offers an improvement to an individual's emotional well-being, only recently researchers at Massachusetts General Hospital (MGH), Boston University (BU) and various other research centers tested the hypothesis that frequently performing mediation could alter and reduce negative emotional stimuli. The report is published in the November issue of Frontiers in Human Neuroscience.

Measuring the emotional response
Beginning with an 8-week meditation program at the Emory University in Atlanta, participants in the study - healthy adults - were placed in one of three different groups. One set practiced mindful attention meditation, another compassion meditation and the last, a control group, was enrolled in an 8-week health education course. 

At two three-week intervals of the study, before it began and three weeks following the end, 12 volunteers representing each group were scanned by functional magnetic resonance imaging (fMRI) at the Athinoula A. Martinos Center in Boston. The testing found that different meditation exercises impact the brain differently, and those effects can be measured .

"Since the compassion meditation is designed to enhance compassionate feelings, it makes sense that it could increase amygdala response to seeing people suffer," said Gaëlle Desbordes, PhD, research fellow at the Martinos Center and at the BU Center for Computational Neuroscience and Neural Technology. "Increased amygdala activation was also correlated with decreased depression scores in the compassion meditation group, which suggests that having more compassion towards others may also be beneficial for oneself."

Enduring brain functions
Following completion of the program, the researchers used the amygdala - a two-sided area in the brain that processes memory and emotion - as a guide, and found that the compassion meditation group had a decrease of activity in the right amygdala when shown images with positive or neutral emotional content. However the mindful attention group showed a decrease in activation of the right amygdala to positive, neutral and negative images.

"Overall, these results are consistent with the overarching hypothesis that mediation may result in enduring, beneficial changes in brain function, especially in the area of emotional processing," explained Desbordes.