Singh proposes a cultural evolutionary theory of shamanic practices, including trance. We argue that cultural factors are deeply intertwined with biological aspects in shaping shamanic practices, and the underlying biology is critical. We discuss the neural underpinnings of rhythm-induced trance, how they can facilitate insight, and how altered states can promote healing.
Trance is an absorptive state of consciousness characterized by narrowed awareness of external surroundings and has long been used-for example, by shamans-to gain insight. Shamans across cultures often induce trance by listening to rhythmic drumming. Using functional magnetic resonance imaging (fMRI), we examined the brain-network configuration associated with trance. Experienced shamanic...