Non-invasive Electrophysiological Characterization of Distinctive Meditative States in a Yogi during Samaadhi.
International journal of yoga January 1, 2025 D Narayana Dutt, G R Ganesh Rao, C R Ramaswamy et al.
During about 30 minutes of meditative Samaadhi, a Yogi par excellence showed a substantial reduction in breathing amplitude to less than 5% of pre-meditation levels, along with subjectively measured decreases in heartbeat and pulse amplitude. Cardiac electrical activity remained intact, but the data suggested a possible considerable reduction in cardiac mechanical activity. Muscle contractions were consistently higher. A unique pattern of alpha and beta activity appeared in frontal EEG electrodes, and occipital electrodes showed alpha with occasional beta activity. With eyes open during meditation, occipital alpha and beta activity persisted, which is atypical because occipital alpha normally vanishes when eyes are open. These patterns were distinct from those of awake, dreaming, and sleeping states.