Age-dependent effective connectivity between functionally anticorrelated networks under partial sleep deprivation

Partial sleep deprivation (PSD) is prevalent in modern societies and is associated with multiple domains of cognitive dysfunction. Evidence suggests that the balance between the default mode network (DMN), dorsal attention network (DAN), and salience network (SN) is crucial for internally and externally directed cognition and may be particularly vulnerable to PSD. This study investigated effective connectivity (EC) within and between these networks and whether these effects differ by age. Resting-state functional magnetic resonance imaging (fMRI) data were analysed using spectral dynamic causal modeling (spDCM) with parametric empirical Bayes after a night of full sleep and following PSD in younger (20–30 years, n = 39) and older (65–75 years, n = 34) adults. Within-network analysis revealed predominantly increased DMN connectivity in younger adults and more selective DMN reductions in older adults. The DAN was the least affected network in the within-network analysis. Further investigation of age-dependent effects showed relatively more PSD-related increases in EC in the older group than in the younger group, particularly within DAN and SN pathways. At the between-network level, younger and older adults showed a broadly similar organization at baseline, but this pattern changed differentially after PSD. In younger adults, PSD amplified the excitatory influence of the SN on the DMN and its inhibitory influence on the DAN. PSD also increased DAN-to-DMN connectivity, whereas older adults showed a partly reversed pattern, with a shift toward increased SN-to-DAN influence. These findings emphasize the age-dependent reorganization of directed relationships within large-scale networks after PSD.