<P> 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 . It is considered to be pseudoscientific and is different from the meaning of "engram" in cognitive psychology . According to Dianetics and Scientology, from conception onwards, whenever something painful happens while the "analytic mind" is unconscious, engrams are supposedly being recorded and stored in an area of the mind Scientology calls the "reactive mind". </P> <P> The term engram was coined in 1904 by the German scholar Richard Semon, who defined it as a "stimulus impression" which could be reactivated by the recurrence of "the energetic conditions which ruled at the generation of the engram ." L. Ron Hubbard re-used Semon's concept when he published Dianetics: The Modern Science of Mental Health in 1950 . He conceived of the engram as a form of "memory trace", an idea which had long existed in medicine . 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 ." Hubbard had originally used the terms "Norn", "comanome" and "impediment" before alighting on "engram" following a suggestion from Winter . Hubbard equates the reactive mind to the engram or reactive memory bank . An engram is described as a "cellular level recording" that includes both physical and emotional pain . Engrams are stored in chains or series of incidents that are similar . Hubbard describes the engram as "a definite and permanent trace left by a stimulus on the protoplasm of a tissue . It is considered a unit group of stimuli impinged solely on the cellular being ." </P>

In the vocabulary of scientologists engrams are defined as