Bourguignon
1 reported that 90% of human societies have institutionalized one or more altered states of consciousness and that 57% of these states are related to possession trances. It is possible that possession trances have a common neurophysiological mechanism across healthy individuals. Although trances involving tranquil arousal states such as Zen, yoga, and transcendental meditation are well studied with spontaneous electroencephalograms (EEGs) (often in laboratories), there are no neurophysiological studies of possession trances involving hyperarousal active states induced within natural contexts in the field. Access to participants who participate in true possession trances is very limited because these trances typically occur within sacred contexts, many of which disallow outside experimenters
2. The functional limitations of equipment for field use further complicate the study of these phenomena
3.
Overcoming these problems, we completed the first successful recordings of EEG signals from a participant in a possession trance in the field in Bali, Indonesia
4. The present study expands upon this initial work. The aim of this study was to examine EEG characteristics during possession trances.
