High-Frequency rTMS Facilitates Mental Fatigue Recovery in Healthy Young Adults

In the contemporary society, mental fatigue is a major challenge to the efficiency of production and safety of daily life, highlighting the necessity of exploring effective intervention strategies. Here, 73 healthy adults (male/female = 36/37, age = 22.6 ± 2.2 yrs) were recruited to participate in a randomized, single-blind, sham-controlled study. Specifically, the high-frequency repetitive transcranial magnetic stimulation (rTMS) was applied to the left dorsolateral prefrontal cortex (DLPFC) in-between a sustained attention task to explore, for the first time, the feasibility and efficacy of promoting fatigue recovery. EEG data obtained during task were then projected to cortical space through source imaging, followed by functional brain network construction and quantitative graph theoretical analysis. Compared to the sham group, the real rTMS group exhibited preserved reaction times and significantly alleviated subjective worry. These behavioral benefits were accompanied by an intervention-related reorganization of brain networks. Specifically, rTMS-related modulation of long-range fronto-temporal connectivity and shifts in nodal centrality within the right fronto-parietal network and the posterior cingulate cortex (PCC) was also revealed. Further inspection of global graphical properties showed that brain network developed toward a higher segregation state after the intervention, as indicated by the increased local efficiency and clustering coefficient. Our findings indicate that high-frequency rTMS mitigates mental fatigue not through passive rest, but by promoting a functional transition of large-scale brain networks toward a more efficient topological state. This study confirmed the feasibility of rTMS as an effective intervention for fatigue recovery, and contributed to the development of precise, neurobiologicallybased strategies for fatigue intervention.