Where Do Memories Go?

Research suggests that the hippocampus, a structure near the core of the brain, maps and organizes memories, then directs them to other sections of the brain, perhaps to several sections at once. Exactly what a memory is made of, however, remains a mystery. There are many theories. One is that a memory is stored as an electrical charge; another is that special "memory molecules" or even entire cells hold memories; a third proposes that remembered information has caused changes in the chemical make-up of some cells. One researcher uses the term mnemon to describe a basic unit of memory that guides the formation of other memories.

Although no single site in the brain seems to have a monopoly on memory, the neocortex holds at least some long-term memories. When stimulated electrically, the neocortex, the brain's gray outermost layer, may release a rush of sensations - sounds, sights, smells - from long ago days.