Meditation induced cortical oscillatory modulations: A MEG case study

Collaborator: Stephen Hall, Aston University, UK

Study Summary:

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.
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