Ethno Therapy, Music and Trance: An EEG Investigation into a Sound-Trance Induction

Abstract

Music has been used since ancient times in healing rituals. It has been played for people to induce altered states of consciousness (ASC), which change the focus of attention, mood, and thoughts about the world and the self. Music and altered states are connected in various ways concerning context, personal set, socio-ecological setting, and cultural beliefs. Discussion is ongoing as to whether music itself induces the changes via a “trance mechanism” or whether the setting and rituals connected to music are responsible for the induction of ASC. The authors conducted an explorative attempt to represent interdependencies of set and setting, sound and trance through electrophysiological correlation in the topographic spontaneous EEG. They opted for a sound trance induction with the sound of a body monochord (a bed-like stringed instrument producing a droning sound) in the context of a group ritual. In comparison with uninfluenced rest, they found individual changes in spontaneous EEG. Trance reactions to sound were seemingly more determined by the person’s susceptibility to hypnosis as measured by the Phenomenology of Consciousness Inventory than by sound alone.