Can we restore memories we’ve lost?

Memories are stored in pieces in various regions of the brain. The different pieces contain information such as the sight, sound, and emotional reactions that occurred during an experience. The pieces are then linked into a coherent combination called a memory engram. Some research in mice suggests that if the brain is temporarily impaired, access to a memory may be temporarily lost, but it’s still there and has the potential to be retrieved later. It’s not clear yet if lost memories can be restored in humans.