FLicKeR is a Canadian documentary film written and directed by Nik Sheehan, produced by Maureen Judge and Silva Basmajian (NFB). The film is based on the book Chapel of Extreme Experience by John G. Geiger about the work of artist Brion Gysin and his Dreamachine. Gysin's Dreamachine used a 100-watt light bulb, a motor, and a rotating cylinder with cutouts. Its users would sit in front of it, close their eyes, and experience visions as a result of the flashes of light. Gysin believed that by offering the world a drugless high the invention could revolutionize human consciousness.