Engram

Part of speech: noun

Pronunciation: /ˈɛnˌɡɹæm/

Definitions

1. A theoretical unit reflecting the idea of a memory stored within neural connections that influences cognitive recall and learning processes
2. A concept representing the physical imprint of a memory within the neural tissue that enables recollection
3. An imagined neurological mark or change believed to encode past experiences inside the brain

Etymology: Richard Semon, a German evolutionary biologist, coined the term in 1904, and he did so to explain how experience could leave a lasting physical trace in living tissue. In his book "Die Mneme" he argued that a stimulus alters organic substance, and he called that altered state the "Engramm" of the stimulus. The sum of the engrams an organism carries was its "Engrammschatz," and he distinguished inherited engrams from those acquired by the individual. The word is built from Ancient Greek "en," meaning "in," and "gramma," meaning "writing" or "picture," so the literal sense is something inscribed within. Semon was writing about a mark pressed into the body rather than on a page, which is why the metaphor of writing suited him. English first recorded the word in 1921, borrowing it directly from German. Its modern meaning, a memory trace stored in the brain, retains Semon's original idea of a physical imprint left by experience.

Synonyms: memory trace, impression, recollection, record, memorial