Characteristic spatiotemporal features of large-scale functional network architecture in posttraumatic stress disorder.

Understanding how trauma reshapes the brain's large-scale functional architecture requires a framework that integrates both spatial and temporal dimensions. In this study, we applied a multimodal analytic framework that combines functional connectivity gradient mapping with energy landscape analysis. This approach allowed us to characterize cortical reconfiguration in trauma-exposed controls (TEC) and individuals with posttraumatic stress disorder (PTSD). Gradient-based analyses revealed widespread spatial displacements along the first two functional dimensions - particularly within the visual, salience and default mode networks - for both TEC and PTSD participants. PTSD participants further displayed amplified disruptions along a higher-order cognitive gradient, indicating a more pronounced breakdown of large-scale functional organization. We also introduced a novel gradient-based distance metric to more precisely quantify topological alterations within the embedding space. State-based modeling of these network dynamics revealed that trauma exposure reshapes the brain's coactivation landscape. While both trauma-exposed controls and PTSD participants deviated from normative dynamic profiles, individuals with PTSD exhibited less frequent but more stable anomalous states. This stability may be indicative of a shift away from flexible adaptation towards pathological consolidation. Our findings delineate how trauma reorganizes brain function across complementary facets of spatial embedding and dynamic coordination, highlighting the utility of integrative frameworks for advancing system-level models of trauma-related disorders. Thus, this work offers a conceptual foothold for future investigations into the functional architecture of PTSD.