Updated

Deutsche Welle published a science explainer on the brain's default mode network (DMN), the group of brain regions that become active when a person is not focused on an external task. The article says the DMN helps people revisit memories, reflect on who they are, imagine future scenarios, understand other people and connect ideas, turning experiences into an internal story of identity. Scientists identified it through brain-imaging experiments in the 1990s and early 2000s, comparing activity during demanding tasks with rest periods. The piece also describes the salience network, which monitors for important signals and shifts attention when action is needed, and says the DMN and this network constantly interact. It notes the DMN is not always beneficial: in depression it can get caught in repetitive negative loops called rumination, and Alzheimer's disease targets key DMN areas linked to autobiographical memory. The article says sleep loss and stress have direct evidence for disrupting DMN connectivity, while the effect of smartphone scrolling on the DMN is unproven. It suggests protecting sleep, taking quiet breaks, and embracing boredom.