Micro-phenomenology of immersion and perceived presences under DMT.

Psychedelic compound N,N-Dimethyltryptamine (DMT) is renowned for inducing highly immersive experiences, often including encounters with seemingly sentient presences. While such phenomena are well documented, immersion under psychedelics remains conceptually underdefined and phenomenologically underexplored. Here we apply micro-phenomenology to characterize immersion under DMT as a structured continuum from subtle to gross forms of immersion, and to examine how perceived presences arise within this continuum. Twenty-three participants received 20 mg intravenous DMT during simultaneous fMRI-EEG acquisition, followed by detailed micro-phenomenological interviews focused on the temporal unfolding of experience. Micro-phenomenological analysis methods yielded 125 phenomenological categories describing structural dimensions, including sensory and amodal faculties, spatial organisation, self-world configuration, and modes of social relatedness. Dynamic analysis revealed reliable developmental patterns, with bodily effects typically preceding visual and auditory ones, and perceived presences emerging only after multisensory integration and 3D spatial characteristics had developed, illustrating a hierarchical relationship between subtle and gross forms of immersion. Perceived presences varied widely in sensory modality, semantic complexity, and relational mode. These findings show immersion under DMT as a dynamic, constructive process, providing precise structural features for future neurophenomenological modelling, and supporting the view that DMT research may inform our understanding of immersive experience across other aetiologies, including ordinary experience of the world.