mnemon
/ˈniːmɒn/Psychology
noun
The minimum physical change in a brain, or other system, which constitutes the storage of a single piece of information in the memory; a unit of memory.
Origin
1960s; earliest use found in John Zachary Young (b. 1907). From ancient Greek μνήμη memory + -on; apparently coined by A. Cherkin, whose forthcoming paper is discussed by Young.