Neuroanthropology of shamanic trance: a case study with a ritual specialist from Mexico.

An 81-year-old Mexican shaman, who recognized her gift in childhood, underwent electroencephalographic recording while performing three activities: reading cards for diagnosis, performing a limpia (cleansing) with eggs, stones, and bells, and entering an incorporation trance believed to allow a deceased entity to use her body as a communication channel. Alpha activity appeared when she was concentrated, suggesting a hypnagogic-like state. Predominant beta and gamma oscillations were observed, indicating a potential plastic phenomenon that modulates the assimilation of external and internal referents, guiding action, attention, and integration of mnemonic, sensory, and imaginative elements. The authors interpret shamanic trance as a biological potential of the human brain to induce non-ordinary states of consciousness shaped by cultural beliefs and practices.

Study at a glance

Abstract

In Mexico, shamans are recognized for the gift of entering a deep trance that allows them to know the origin of the diseases and conflicts that afflict people. They commonly treat patients through limpias (cleansing) to extract negative elements sent by a witch or that were "collected" in places that harbor "evil winds." We present a case study of an 81-year-old Mexican shaman who noticed her gift in childhood. Electroencephalographic recordings were made while the shaman performed three activities: reading cards to diagnose a patient and answer the questions he posed; limpia with chicken eggs, stones, and bells to absorb adverse "things"; and the incorporation trance through which the deceased is believed to occupy the shaman's body to use it as a communication channel. Alpha activity was observed when concentrated, suggesting a hypnagogic-like state. Predominant beta and gamma oscillations were observed, suggesting a potential plastic phenomenon that modulates the assimilation of external and internal referents guiding temporal schemes for action, attention, and the integration of mnemonic, sensory, and imaginative elements. We used a neuroanthropological approach to understand shamanic trance as a biological potential of the human brain to induce non-ordinary states of consciousness linked to cultural beliefs and practices.