Advanced concentrative absorption meditation reorganizes functional connectivity gradients of the brain: 7T MRI and phenomenology case study of jhana meditation.

There is growing scientific interest in advanced meditation, and particularly the Theravada Buddhist advanced concentrative absorption meditation known as jhana (ACAM-J). ACAM-J includes a series of eight consecutive meditative states, which are radically altered states of consciousness. The neuroscience of ACAM-J, specifically brain reorganization, remains underspecified in part due to the difficulty of finding and studying expert ACAM-J meditators and challenges related to laboratory investigation of ACAM-J. Using a nonlinear dimensionality reduction technique applied to human functional neuroimaging in an intensive case study, we investigated brain reorganization during ACAM-J. We applied linear mixed models and correlations to explore relations among brain reorganization and ACAM-J phenomenology. Results demonstrated that ACAM-J induces disruption of the hierarchical organization of the brain by shifting the gradients toward a more globally integrated rather than segregated state between sensory-related and higher-order cognitive regions. Additionally, ACAM-J induces a separation between sensory-related and attention modulation-related regions, resulting in greater differentiation in functional organization of these regions, consistent with phenomenological reports. This study highlights the need for further research into brain reorganization and health-related implications of both short-term and long-term practice of ACAM-J. Key points/highlights The neuroscience of advanced concentrative absorption meditation (ACAM) has the potential to improve our knowledge of well-being and altered states of consciousness but remains underexplored due to methodological challenges. We investigated functional reorganization of the brain during ACAM-J using gradient analysis and demonstrated that ACAM-J disrupts the hierarchical organization of the brain during meditation. Additionally, we demonstrated that ACAM-J increases differentiation between primary sensory areas and areas related to attention modulation.