Decoding Depth of Meditation: EEG Insights from Expert Vipassana Practitioners

Meditation practices have demonstrated numerous psychological and physiological benefits, yet capturing the neural correlates of varying meditative depths remains challenging. This study aimed to decode self-reported time-varying meditative depth in expert practitioners using EEG. Expert Vipassana meditators (n=34) participated in two separate sessions. Participants reported their meditative depth on a personally defined 1-5 scale using both traditional probing and a novel "spontaneous emergence" method. EEG activity and effective connectivity in theta, alpha, and gamma bands was used to predict meditative depth using machine/deep learning, including a novel method that fused source activity and connectivity information. We achieved significant accuracy in decoding self-reported meditative depth across unseen sessions. The "spontaneous emergence" method yielded improved decoding performance to traditional probing and correlated more strongly with post-session outcome measures. Best performance was achieved by a novel machine learning method which fused spatial, spectral, and connectivity information. Conventional EEG channel-level methods and pre-selected default mode network regions fell short in capturing the complex neural dynamics associated with varying meditation depths. This study demonstrates the feasibility of decoding personally defined meditative depth using EEG. The findings highlight the complex, multivariate nature of neural activity during meditation and introduce "spontaneous emergence" as an ecologically valid and less obtrusive experiential sampling method. These results have implications for advancing neurofeedback techniques and enhancing our understanding of meditative practices.