An engram, as used in Dianetics and Scientology, is a detailed mental image or memory of a traumatic event from the past that occurred when an individual was partially or fully unconscious.
"[7] L. Ron Hubbard re-used Semon's concept when he published Dianetics: The Modern Science of Mental Health in 1950.
According to physician Joseph Winter, who collaborated in the development of the Dianetics philosophy, Hubbard had taken the term "engram" from a 1936 edition of Dorland's Medical Dictionary, where it was defined as "a lasting mark or trace...In psychology it is the lasting trace left in the psyche by anything that has been experienced psychically; a latent memory picture.
He later repudiated the idea that an engram was a physical cellular trace, redefining his concept as being "a mental image picture of a moment of pain and unconsciousness".
[10] Scholar Richard Holloway writes that according to Scientology, engrams are "damaging experiences that happen by accident," bruises through time implanted on thetans through the course of millions of lives.
Hubbard wrote, "Implants result in all varieties of illness, apathy, degradiation, neurosis and insanity and are the principle causes of these in man."