A new study discovers participation in a meditation program can impact brain functions even when someone is not actively meditating.
Investigators at Massachusetts General Hospital (MGH), Boston University (BU), and several other research centers also discovered brain changes were specifically linked to the type of meditation practiced.
Research findings are published in the journal Frontiers in Human Neuroscience.
“The two different types of meditation training our study participants completed yielded some differences in the response of the amygdala — a part of the brain known for decades to be important for emotion — to images with emotional content,” said Gaëlle Desbordes, Ph.D., corresponding author of the report.
“This is the first time that meditation training has been shown to affect emotional processing in the brain outside of a meditative state.”
Prior research has established a link between meditation training and improved emotional regulation among practitioners.
However, although neuroimaging studies have found that meditation training appeared to decrease activation of the amygdala – a structure at the base of the brain that is known to have a role in processing memory and emotion – those changes were only observed while study participants were meditating.
In the new study, researchers investigated the hypothesis that meditation training could also produce a generalized reduction in amygdala response to emotional stimuli – a response that can be measurable by functional magnetic resonance imaging (fMRI).
Participants had enrolled in a larger investigation into the effects of two forms of meditation, based at Emory University in Atlanta.
Healthy adults with no experience meditating participated in 8-week courses in either mindful attention meditation — the most commonly studied form that focuses on developing attention and awareness of breathing, thoughts and emotions — and compassion meditation, a less-studied form that includes methods designed to develop loving-kindness and compassion for oneself and for others.
A control group participated in an 8-week health education course. fMRI brain imaging was performed on 12 participants within three weeks before beginning and three weeks after completing the training.
The scans were performed as the volunteers viewed a series of 216 different images – 108 per session – of people in situations with either positive, negative or neutral emotional content.
Meditation was not mentioned in pre-imaging instructions to participants, and investigators confirmed afterwards that the volunteers had not meditated while in the scanner.
Participants also completed assessments of symptoms of depression and anxiety before and after the training programs.
In the mindful attention group, the after-training brain scans showed a decrease in activation in the right amygdala in response to all images, supporting the hypothesis that meditation can improve emotional stability and response to stress.
In the compassion meditation group, right amygdala activity also decreased in response to positive or neutral images.
But among those who reported practicing compassion meditation most frequently outside of the training sessions, right amygdala activity tended to increase in response to negative images – all of which depicted some form of human suffering.
No significant changes were seen in the control group or in the left amygdala of any study participants.
“We think these two forms of meditation cultivate different aspects of mind,” Desbordes said. “Since compassion meditation is designed to enhance compassionate feelings, it makes sense that it could increase amygdala response to seeing people suffer.”
Researchers also found that 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.
Desbordes believes the results are consistent with the overarching hypothesis that meditation may result in enduring, beneficial changes in brain function, especially in the area of emotional processing.
Source: Massachusetts General Hospital