DRAMATIC MODULATIONS OF BRAIN ACTIVITY INDUCED DURING MEDITATION:
A MEG CASE STUDY
Meditation is both an ancient spiritual practice as well as a contemporary technique for relaxing the body and calming the mind. It is recognized as a component of almost all religions, and has been practiced for over 5,000 years. Meditative techniques originally came from Asian religious practices and have been widely adopted in western society, where the health benefits associated with meditation have become widely recognised. Research suggests that meditation is of therapeutic advantage in the treatment of many clinical disorders such as epilepsy, although the basis of this effect in terms of electrical brain activity and other processes is unclear.
To better understand how this ancient practice affects the brain we used magnetoencephalography (MEG) to measure changes in brain activity during meditation. The mystical experiences brought about by meditation were recorded and evaluated and the influence these experiences were correlated with brain activity.
We invited a senior member of the Brahma Kumaris World Spiritual Organisation, with more than 30 years of expertise in meditative practice, to participate in this study. During the meditation session, while we recorded MEG measures of brain activity, the meditator experienced a strong sense of ‘oneness’ (unity) and light, alongside a reduced awareness of the self and what was going on around her (a silencing of the usual noise of the mind).
The results demonstrated strong desynchronisation over somatosensory, auditory and visual cortices, which seem likely to reflect the reduction in attention to sensory processing. The increases in synchronous gamma activity in the cerebellum was associated with her acute experience of unity and light. The results also demonstrated that although meditation is a technique employed for relaxation, it stimulates a substantial increase in circulatory rate (from 60 to 90bpm), which possibly reflects an increased neural metabolic demand.
What is clear from this study is that meditation is an active process, which directly modulates the oscillatory activity of the brain. The findings from a single participant demonstrated up to 180% change in oscillatory power (in the gamma frequency range), which is orders of magnitude greater than any MEG study has previously reported.
This Figure shows synchronisation in the cerebellum during the meditation phase. Demonstrating an increase in activity in the gamma (30-70Hz) frequency range. This result is particularly pronounced (>150%) in the second phase of meditation (20-30 minutes).
The synchronisation of gamma activity evident in the right cerebellum represents the most substantial increase seen in brain oscillatory activity from baseline to meditative state. If any comparison can be made between these objective measures and subjective experience, we would tentatively suggest that synchronisation might be related to the process of heightened conscious attention.