Cognitive and Perceptual Augmentation Through Neuromodulation during Fatiguing Tasks is Sex-specific

Transformative paradigms to proactively mitigate fatigue through noninvasive neurostimulation, such as transcranial direct current stimulation (tDCS), have been shown to be more effective than existing interventions. The study aimed to evaluate the effectiveness of HD-tDCS (High-Definition) as a fatigue countermeasure on vigilance and perceived fatigue on longer bouts of mental fatigue. Thirty-two participants were assigned to active stimulation and sham groups, and they took part in a 2 hr fatigue protocol of 2-back visuospatial working-memory tests. To evaluate the effect of active stimulation, separate linear mixed-effect models with the group (stimulation/sham), phase (pre/post), and sex (male/female) were analyzed. The results showed the effectiveness of HD-tDCS in slowing fatigue-related declines across both cognitive and perceptual channels, with fatigue reduction being more effective in women. These observations could inform sex-based considerations to improve the operational readiness of tDCS-based countermeasure systems to help mitigate fatigue among emergency and military personnel.