Hierarchical structural-functional coupling reorganization after acute sleep deprivation: Links to spatial working memory and lateralization.

Although previous studies have documented acute sleep deprivation (ASD)-induced alterations in brain structure and function, how the hierarchical coupling between these two modalities is reorganized following ASD, and whether such reorganization is associated with spatial working memory (SWM), remain to be systematically elucidated. Fifty healthy adult males completed a 1-back SWM task and underwent multimodal magnetic resonance imaging before and after ASD. We systematically examined ASD-related changes in structural-functional (SC-FC) coupling at three hierarchical levels (regional, intra-network, and inter-network) and assessed their associations with SWM performance. Finally, this study calculated the lateralization index (LI) of SC-FC coupling and evaluated its ability to discriminate ASD from normal sleep states. Compared with the baseline state, ASD induced significant reorganization of SC-FC coupling, exhibiting pronounced regional specificity and hierarchical differences. In particular, both regional and inter-network SC-FC coupling of the left limbic network showed a trend-level negative correlation with omission rate after ASD. In addition, the LI of SC-FC coupling in the subcortical network exhibited a moderate level of discriminative performance in distinguishing between the two states. Multilevel reorganization of SC-FC coupling induced by ASD provides new evidence for the neural mechanisms underlying SWM impairment. Moreover, the lateralization features of SC-FC coupling show potential as neuroimaging biomarkers for fatigue or state monitoring.