How does fatigue affect cognitive load through emotion regulation strategies in unmanned forklift scenarios?

<i>Objectives</i>. Operators monitoring unmanned forklifts may still experience fatigue despite relatively low physical demands, which can increase cognitive load and pose safety risks. Emotion regulation may buffer fatigue-related impairment, but the mechanisms remain unclear, particularly for two emotion regulation strategies: cognitive reappraisal and expressive suppression. This study examined whether emotion regulation strategies mediate the association between multidimensional fatigue and cognitive load in unmanned forklift monitoring. <i>Methods</i>. Sixty-five participants completed a monitoring task involving unmanned forklift trucks and reported fatigue (task engagement, distress, worry), emotion regulation strategies (cognitive reappraisal, expressive suppression) and cognitive load via self-report scales. <i>Results</i>. Structural equation modeling analysis revealed that higher levels of task engagement - serving as an indicator of fatigue - were associated with higher self-reported propensities for cognitive reappraisal. Moreover, individuals who more frequently employed a cognitive reappraisal strategy reported lower levels of cognitive load. Cognitive reappraisal significantly mediated the relationship between task engagement and cognitive load. Through fuzzy-set qualitative comparative analysis, this study identified four distinct configurations that reduce cognitive load. <i>Conclusion</i>. The findings underscore the importance of emotion regulation for understanding cognitive demands in unmanned forklift scenarios. Future research could expand intervention approaches to better support operators' psychological well-being in such settings.