Distinctive and Complementary Roles of Default Mode Network Subsystems in Semantic Cognition
Journal of Neuroscience April 8, 2024 Ximing Shao, Katya Krieger‐Redwood, Meichao Zhang et al. 20 citations
The default mode network (DMN) typically deactivates during external tasks but supports semantic cognition. Analysis of four human fMRI datasets shows that its subsystems respond differently: the frontotemporal subsystem activates across domains and modalities, especially during abstract verbal tasks, and shows more tuned states with higher semantic retrieval demands. The medial temporal subsystem activates for both perceptually coupled scenes and decoupled autobiographical memory, with stronger responses to picture associations, supporting scene construction. The core DMN consistently deactivates, particularly for externally oriented tasks. These distinct responses relate to each subsystem's location on intrinsic connectivity gradients, revealing complementary roles in semantic cognition.