Inspired by the work of John C. Lilly, Chayefsky spent two years in Boston doing research to write his science fiction novel Altered States (HarperCollins, 1978), which he adapted for his last screenplay. In the film Chayefsky is credited under his real first and middle name, Sidney Aaron, because of disputes with director Ken Russell. Some of the events portrayed in this film seem to be based on the studies of the French surrealist author Antonin Artaud; the protagonist visits a tribe of isolated Mexican tribal people & participates in their sacred shamanic ritual involving local hallucinogens for the purpose of investigating the common religious experience. Much of the setting of this part of the film also appears to be based on Artaud's description of the natural, altho seemingly man-made landscape of the people. In the movie, this was represented by huge stone mushrooms often called hoodoos & attributed to the supernatural.
