Trance, an absorptive state with narrowed external awareness used by shamans for insight, was studied with fMRI in 15 experienced shamanic practitioners listening to rhythmic drumming. During trance, three brain regions—posterior cingulate cortex, dorsal anterior cingulate cortex, and left insula/operculum—showed stronger hubs (higher eigenvector centrality). The posterior cingulate cortex, a default network hub for internal thought, coactivated with control-network regions, suggesting amplified internal neural streams. Auditory pathway seeds were less connected, indicating perceptual decoupling from repetitive drumming. This network reconfiguration may support extended internal thought and insight.
Nondual meditation, specifically Open Presence (OP) practice, is associated with reduced bodily self susceptibility and increased large-scale integration of functional brain networks. Expert meditators with over 10,000 hours of practice showed lower global network eccentricity during OP compared to novices, particularly in dorsal attention, ventral attention, and frontoparietal networks, indicating greater integration. These neural patterns correlated positively with measures of bodily self illusion and negatively with cognitive defusion, a construct reflecting reduced self-grasping toward thoughts. The findings suggest that nondual awareness involves alterations in self-representation and large-scale functional brain integration.