In one experienced compassion meditator, generating feelings of love and compassion while reciting a mantra activated the left medial prefrontal cortex extending to the anterior cingulate gyrus, as well as the right caudate body extending to the right insula and the left midbrain near the hypothalamus. These brain areas are involved with empathy and pleasant feelings, supporting the hypothesis that compassion meditation engages neural circuits related to social emotions.
Moderately experienced meditators with less than two years of practice show significant activation in the hippocampus and parahippocampal formations during silent mantra meditation, as measured by functional magnetic resonance imaging. Activation also occurred in the middle cingulate cortex and precentral cortex, but not in the anterior cingulate cortex, and only small clusters appeared in the prefrontal cortex. The findings suggest that hippocampal activation occurs early in meditation practice and across different meditation styles, including relaxation. The authors propose further research to clarify whether this hippocampal activity relates to memory consolidation.