General anaesthesia as fragmentation of selfhood: insights from electroencephalography and neuroimaging
British Journal of Anaesthesia February 4, 2018 Jamie Sleigh, Catherine E. Warnaby, Irene Tracey 35 citations
Selfhood depends on brain processes that allow a person to experience being a distinct, capable agent. It includes a hierarchy of components: core self (awareness of existence), embodied self (sentience), executive self (agency), and higher-order cognition. Consciousness and selfhood are related but not identical; understanding selfhood helps explain partial consciousness during anesthesia. Brain-imaging and EEG studies show that anesthetic drugs selectively impair self-related networks, especially the anterior insula and salience network, causing depersonalization at moderate doses while preserving disembodied self-awareness. Unlike natural sleep, where loss of agency and sentience tracks with decreasing self-awareness, anesthesia maintains posterior brain connectivity even at high concentrations, possibly marking a core self involved in reduced energy homeostasis.