fMRI studies of meditation

Meditation is a conscious mental process that influences attention and emotional regulation. It has also been shown that meditation involves health-promoting benefits like stress reduction, decreased blood pressure, and higher pain threshold. However, the biological mechanisms behind the body’s response to meditation are poorly understood. Neuro-imaging is regarded as one of the most promising tools for investigations of the coupling between the mind and the body during meditation. Within this project the neural correlates to meditation are investigated by functional Magnetic Resonance Imaging (fMRI).

• Staff:

Birfgitta Söderfeldt , MD, PhD		Project Manager		Karolinska sjukh
Maria Engström , PhD				IMV/CMIV
Peter Lundberg , PhD				IMV/Radiation Physics

• Former Staff:

Jacob Moell , Student
Johan Pihlsgård , Student
Ulrika Berglind

• Project Description:

Studies on meditation


1. Brain activation achieved by compassion meditation

One Tibetan Buddhist with many years of compassion meditation practice participated in the study. During meditation the subject uses a technique to generate a feeling of love and compassion while reciting a mantra. The aim of the  study was to investigate the neural correlates of compassion meditation in one experienced meditator by functional Magnetic Resonance Imaging (fMRI). The most significant finding was the activation in the left medial prefrontal cortex extending to the anterior cingulate gyrus. Other significant loci of activation were observed in the right caudate body extending to the right insula and in the left midbrain close to the hypothalamus. The results in this study are in concordance with the hypothesis that compassion meditation is accompanied by activation in brain areas involved with empathy as well as with happy and pleasant feelings, i.e. the left medial prefrontal cortex and the anterior cingulate gyrus.

Reference

M. Engström and B. Söderfeldt. Brain activation during compassion meditation: a case study. In press  J. Alternative and Complimentary Medicine, 2010.






2. Functional Magnetic Resonance Imaging of Hippocampal Activation During Silent Mantra Meditation

Objectives: 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.



Reference

M. Engström, J. Pihlsgård, P. Lundberg, and Birgitta Söderfeldt. Functional magnetic resonance imaging of hippocampal activity during silent mantra meditation. J Alternative and Complimentary Medicine, 16:1253-1258, 2010, 2010.