Increased gray matter volume in the right angular and posterior parahippocampal gyri in loving-kindness meditators

Abstract

Previous voxel-based morphometry (VBM) studies have revealed that meditation is associated with structural brain changes in regions underlying cognitive processes that are required for attention or mindfulness during meditation. This VBM study examined brain changes related to the practice of an emotion-oriented meditation: loving-kindness meditation (LKM). A 3 T magnetic resonance imaging (MRI) scanner captured images of the brain structures of 25 men, 10 of whom had practiced LKM in the Theravada tradition for at least 5 years. Compared with novices, more gray matter volume was detected in the right angular and posterior parahippocampal gyri in LKM experts. The right angular gyrus has not been previously reported to have structural differences associated with meditation, and its specific role in mind and cognitive empathy theory suggests the uniqueness of this finding for LKM practice. These regions are important for affective regulation associated with empathic response, anxiety and mood. At the same time, gray matter volume in the left temporal lobe in the LKM experts appeared to be greater, an observation that has also been reported in previous MRI meditation studies on meditation styles other than LKM. Overall, the findings of our study suggest that experience in LKM may influence brain structures associated with affective regulation.

Fig. 1

Increased gray matter volumes in LKM experts compared with novices as revealed by VBM-Dartel. On the left side are the group differences (LKM experts > novices) overlaid on the average of the bias-corrected images of all subjects. On the right side are the glass brains showing all the clusters that survived corrected P < 0.05 or P < 0.1. Significant effects (P < 0.05, corrected) were detected in the (A) right angular and (B) posterior parahippocampal gyri. Trend-level effect (P < 0.1, corrected) was detected in the (C) left temporal lobe. No significant group differences were found for the opposite contrast (LKM experts < novices). Controlling for age or years of education did not affect the results.