Integrated Phenomenology and Brain Connectivity Demonstrate Changes in Nonlinear Processing in Jhana Advanced Meditation.

During an advanced concentrative absorption meditation called jhana, characterized by highly stable attention and mental absorption, the brain's nonoscillatory dynamics—captured by nonlinear connectivity metrics—distinguish the meditative state better than oscillatory synchrony. Combining attention-related phenomenological ratings with these nonlinear metrics improves the detection of the meditative state compared to using neural data alone. Deeper absorption states show an equalization of feedback and feedforward processes, suggesting a balance between internally and externally driven information processing. The findings, based on EEG recordings from a single meditator with over 20,000 hours of practice across 29 sessions, offer initial insights into the distinct neural dynamics of refined conscious states.

Study at a glance

Abstract

We present a neurophenomenological case study investigating distinct neural connectivity regimes during an advanced concentrative absorption meditation called jhana (ACAM-J), characterized by highly stable attention and mental absorption. Using EEG recordings and phenomenological ratings (29 sessions) from a meditator with +20,000 hr of practice, we evaluated connectivity metrics tracking distinct large-scale neural interactions: nonlinear (weighted symbolic mutual information and directed information), capturing nonoscillatory dynamics, and linear (weighted phase lag index) connectivity metrics, capturing oscillatory synchrony. Results demonstrate ACAM-J are better distinguished by nonoscillatory compared with oscillatory dynamics across multiple frequency ranges. Furthermore, combining attention-related phenomenological ratings with weighted symbolic mutual information improves Bayesian decoding of ACAM-J compared with neural metrics alone. Crucially, deeper ACAM-J indicate an equalization of feedback and feedforward processes, suggesting a balance of internally and externally driven information processing. The results from this intensively sampled case study are a promising initial step in revealing the distinct neural dynamics during ACAM-J, offering insights into refined conscious states and highlighting the value of nonlinear neurophenomenological approaches to studying attentional states.