A rested development: Effort regulation strategy maintains task performance but alters ERPs in task-induced cognitive fatigue

The effects of task-induced cognitive fatigue on performance, strategy, and P300 event-related potentials (ERPs) were examined. Fatigue was induced by task load with participants completing either 700 mental rotation trials with (high fatigue) or without (low fatigue) a secondary task to increase fatigue. No differences were found between groups when examining mental rotation task decision accuracy or strategy; however, the number of trials in which the participant's total trial time was greater than twice their average was influenced by experimental manipulations designed to increase task difficulty. These 'minibreaks', referred to as blocking, may have served to regulate effort expenditure in order to preserve task performance. P300 peak amplitude differed between groups, with high blocking participants showing a reduced amplitude and more dispersed P300 topology compared to low blockers. These results provide compelling evidence that performance outcome may not be affected by task demands if a compensatory effort strategy is utilized.