Altered self-experiences arise in certain psychiatric conditions, and may be induced by psychoactive drugs and spiritual/religious practices. Recently, a neuroscience of self-experience has begun to crystallise, drawing upon findings from functional neuroimaging and altered states of consciousness occasioned by psychedelic drugs. This advance may be of great importance for psychiatry.
Nour, M. M., & Carhart-Harris, R. L. (2017). Psychedelics and the science of self-experience. 10.1192/bjp.bp.116.194738