Functional magnetic resonance imaging of hippocampal activation during silent mantra meditation.
OBJECTIVE
The objective of the present study was to investigate whether moderately experienced meditators activate hippocampus and the prefrontal cortex during silent mantra meditation, as has been observed in earlier studies on subjects with several years of practice.


METHODS
Subjects with less than 2 years of meditation practice according to the Kundalini yoga or Acem tradition were examined by functional magnetic resonance imaging during silent mantra meditation, using an on-off block design. Whole-brain as well as region-of-interest analyses were performed.


RESULTS
The most significant activation was found in the bilateral hippocampus/parahippocampal formations. Other areas with significant activation were the bilateral middle cingulate cortex and the bilateral precentral cortex. No activation in the anterior cingulate cortex was found, and only small activation clusters were observed in the prefrontal cortex.


CONCLUSIONS
In conclusion, the main finding in this study was the significant activation in the hippocampi, which also has been correlated with meditation in several previous studies on very experienced meditators. We propose that the hippocampus is activated already after moderate meditation practice and also during different modes of meditation, including relaxation. The role of hippocampal activity during meditation should be further clarified in future studies, especially by investigating whether the meditation-correlated hippocampal activity is related to memory consolidation.
Center for Medical Image Science and Visualization, Linköping University, Linköping, Sweden. maria.engstrom@liu.se
Maria
M
Engström
Johan
J
Pihlsgård
Peter
P
Lundberg
Birgitta
B
Söderfeldt
D000328:Adult; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology; D005260:Female; D006179:Gyrus Cinguli / Q000502:physiology; D006624:Hippocampus / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D019122:Meditation; D008875:Middle Aged; D015013:Yoga; D055815:Young Adult