This work has revealed striking similarities between remembering the past and imagining or simulating the future, including the finding that a common brain network underlies both memory and imagination. Here we discuss a number of key points that have emerged during recent years, focusing in particular on the importance of distinguishing between temporal and non-temporal factors in analyses of memory and imagination, the nature of differences between remembering the past and imagining the future, the identification of component processes that comprise the default network supporting memory-based simulations, and the finding that this network can couple flexibly with other networks to support complex goal-directed simulations. This growing area of research has broadened our conception of memory by highlighting the many ways in which memory supports adaptive functioning.
TLDR: Memory is complex and the human brain is multi-plex and uses a lot of re-usability and optimization. Meaning memory and imagination use the same systems. Think of it like a system that has components A, B, C, D, E, F. Memory uses A, C,D, E Then imagination uses B, C, D, E. Lots of overlap depending on context.
