Zazen meditation and no-task resting EEG compared with LORETA intracortical source localization.

During Zazen meditation, experienced practitioners show increased alpha-1 and alpha-2 brain wave activity in a right-lateralized cluster spanning prefrontal areas, insula, somatosensory, motor, and temporal cortices compared to resting without a task. Decreased alpha and beta-2 activity occurs in the left angular gyrus, and decreased beta-1 and beta-2 activity in a large bilateral posterior cluster including visual cortex, posterior cingulate cortex, and parietal cortex. These patterns involve parts of the default mode network and suggest enhanced automatic memory and emotion processing alongside reduced conceptual thinking and self-reference, supporting a more detached moment-to-moment awareness during Zazen.

Study at a glance

Abstract

Meditation is a self-induced and willfully initiated practice that alters the state of consciousness. The meditation practice of Zazen, like many other meditation practices, aims at disregarding intrusive thoughts while controlling body posture. It is an open monitoring meditation characterized by detached moment-to-moment awareness and reduced conceptual thinking and self-reference. Which brain areas differ in electric activity during Zazen compared to task-free resting? Since scalp electroencephalography (EEG) waveforms are reference-dependent, conclusions about the localization of active brain areas are ambiguous. Computing intracerebral source models from the scalp EEG data solves this problem. In the present study, we applied source modeling using low resolution brain electromagnetic tomography (LORETA) to 58-channel scalp EEG data recorded from 15 experienced Zen meditators during Zazen and no-task resting. Zazen compared to no-task resting showed increased alpha-1 and alpha-2 frequency activity in an exclusively right-lateralized cluster extending from prefrontal areas including the insula to parts of the somatosensory and motor cortices and temporal areas. Zazen also showed decreased alpha and beta-2 activity in the left angular gyrus and decreased beta-1 and beta-2 activity in a large bilateral posterior cluster comprising the visual cortex, the posterior cingulate cortex and the parietal cortex. The results include parts of the default mode network and suggest enhanced automatic memory and emotion processing, reduced conceptual thinking and self-reference on a less judgmental, i.e., more detached moment-to-moment basis during Zazen compared to no-task resting.