Contributions of default mode network to subjective valuation and maladaptive decision making

The default mode network (DMN) has been central to cognitive neuroscience research for over two decades, yet understanding of its contribution to decision-making remains incomplete. This review synthesizes recent evidence demonstrating that the DMN directly supports subjective valuation and value-based decision-making. Anatomically and functionally, core DMN regions-including the ventromedial prefrontal cortex and posterior cingulate cortex-overlap extensively with the brain's valuation system, suggesting that they may perform shared computational roles. Further, emerging research has identified distinct subregions within the posterior cingulate cortex that support different aspects of internal simulation, memory retrieval, and evaluative processing. Beyond localized activation, the DMN dynamically interacts with reward-related regions (such as the ventral striatum), memory systems (such as the hippocampus), and frontoparietal control networks during value-guided decisions, especially in social contexts. These network interactions flexibly shift with motivational demands and individual differences, providing new insights into how subjective value emerges across diverse situations. Disruptions in these network dynamics have been documented throughout development and in psychiatric conditions, including depression and schizophrenia, revealing mechanisms that underpin maladaptive decision making. Collectively, these findings position the DMN not as a passive or task-negative system, but rather as an integrative hub essential for constructing internal valuations and guiding goal-directed behavior.