The Default Mode Network: Where Spontaneous Thought Meets Memory Consolidation

The default mode network (DMN) is a distributed set of brain regions that is active during task-free, or “resting state,” periods. Various cognitive processes operate autonomously in the absence of external inputs or demands. Spontaneous thoughts—mental experiences that accompany ongoing cognition—are ubiquitous during wakeful rest. Spontaneous memory reactivations—neural events that replay recently learned information—also occur at rest and have a fundamental role in long-term memory consolidation. Here we review recent research on how the DMN may act as a neural workspace to jointly support spontaneous thought and memory consolidation. We identify gaps in the current understanding of the DMN’s function and propose avenues to study how spontaneous thought and memory systems may operate synergistically. Through our review of closely related yet traditionally siloed literatures, we aim to bridge the gap between research on spontaneous thought and memory consolidation to advance understanding of the DMN’s function.