The role of hallucinogenic drugs and sensory stimuli in Peruvian ritual healing.

On Peru's north coast, curanderos perform night-long curing ceremonies in which the mescaline-bearing cactus San Pedro is used. The concept of autonomic nervous system tuning is presented as the best explanation for the overall physiological effect of the ritual. An assessment of the possible therapeutic impact of this condition is provided. Organic response and symbolic message are seen to resonate in the purificatory connotations of the ritual.