Analysis of brain criticality and complexity in the meditative state

Meditation practices are widely recognized as potentially valuable means for promoting physical and mental health, but to date the mechanisms underlying these benefits remain unclear. In this study we investigate the effects of meditation on brain signals by analyzing electroencephalographic (EEG) data from three different groups of meditators (Himalaya Yoga Tradition, Vipassana, and Isha Shoonya Yoga) and a control group. The EEG dataset is publicly available and was collected at the Meditation Research Institute (MRI) in Rishikesh, India[1]. Participants performed two 20-minute sessions: one of meditation and the other of mind wandering. During the first 10 minutes of the meditation session, they were asked to pay attention exclusively to their breath. Starting from the preprocessed EEG data we computed several complexity and criticality related measures: Higuchi Fractal Dimension, Lempel-Ziv, Long Range Temporal Correlation, Power Spectral Density, Slope of the Aperiodic Component of the Power Spectrum and Sample Entropy. By comparing three conditions (breath focus, meditation and mind wandering) within each group, we found that changes in brain criticality and complexity characteristic of the meditative state already begin during the breath focus phase. These findings provide new insights into the early neural mechanisms of meditation.