Control over the scheduling of simulated office work reduces the impact of workload on mental fatigue and task performance.

Two experiments tested the hypothesis that task-induced mental fatigue is moderated by control over work scheduling. Participants worked for 2 hr on simulated office work, with control manipulated by a yoking procedure. Matched participants were assigned to conditions of either high control (HC) or low control (LC). HC participants decided their own task scheduling, whereas LC participants had to follow these fixed schedules. For Experiment 1, fatigue was higher in LC participants who worked harder, so Experiment 2 compared control effects in high- and low-workload groups. As predicted, the impact of workload was reduced under HC conditions, for subjective fatigue, and most secondary tasks and aftereffects. The findings are interpreted within the framework of compensatory control theory.