Development and recovery time of mental fatigue and its impact on motor function.

Abstract Mental fatigue is commonplace but there is limited understanding of the neural underpinnings of its development, the time course of its recovery, and its impact on motor function. Hence, this study used neural (electroencephalography) and motor measures to investigate the development and recovery of mental fatigue. Twenty participants performed a 60-minute N-back task, with neural activity compared within the task. Additionally, pre-task neural and motor measures were compared to assessments beginning at 0, 30 and 60 minutes post-task. Alpha power increased during the task and was greater than baseline at 30 and 60 minutes post-task. Motor skills were impaired at ∼10-15 minutes post-task but recovered at ∼40-45 minutes. Using a unique combination of neural and motor measures, our results suggest that attentiveness and, possibly, selectiveness in inhibiting irrelevant information are impaired after an acute mentally-fatiguing task. Notably, recovery time differed for neural and motor measures.