Psychorama, also called the precon process, is the act of communicating subliminal information through film by flashing images on the screen so quickly that they cannot be perceived by the conscious mind.
In 1958, a film called My World Dies Screaming (later retitled Terror in the Haunted House) marked Hollywood's first attempt to make use of this technique.
In it, images of bones, skulls, houses, fires, and videos of the band performing are flashed at various intervals.
Evanescence also utilized samples from "My World Dies Screaming" in some versions of their song "Understanding", the demo of "Whisper" and the introduction to the album Origin.
The TV show Babylon 5 featured an in-universe reference to supposed psychorama (the words "Trust the Corps" and "The Corps is Your Friend" appear on screen for four frames), although it is debatable whether intentional in-universe references are true psychorama.