The Mazatec velada, a ritual of divination and healing involving sacred mushrooms, is examined through both its cultural context and findings from experimental neuroscience. Psilocybin's effects on neurobiology—emotions, decision-making, and sensory imagery—help explain the subjective experiences of participants. However, experimental research often overlooks an individual's personal and collective history, which the velada incorporates. The authors argue that the ritual can inform experimental designs by integrating a person's history and beliefs. The resurgence of psychedelic medicine calls for a transdisciplinary dialogue merging anthropological perspectives with the set and setting of the entheogenic experience.
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.