Electroencephalography when meditation advances: a case-based time-series analysis.
Cognitive processing November 1, 2013 Jui-Feng Tsai, Shaw-Hwa Jou, WenChun Cho et al.
During breath meditation, theta brainwave activity increased significantly compared to rest, but alpha activity did not. When the meditator reached an advanced meditative stage, both alpha and theta activity increased significantly compared to breath meditation alone. Compared to rest, the advanced stage showed significantly higher alpha and theta activity. The findings suggest that internalized attention, reflected by theta activity, strengthens progressively through meditation phases, while relaxation, reflected by alpha activity, becomes significant only after reaching an advanced stage.