Mental fatigue can be defined either semantically, or though the consideration of an operational setting. For the purposes of this paper, a working operational definition of mental fatigue has been chosen and reflects changes in performance, which are attributed to time-on-task. A consideration of the effects of fatigue on different human information processing stages will be considered, through an examination of sensory, detection, and motor related ERP components. Data recorded during two studies will be reported. In the first of these studies subjects performed a visual oddball procedure for a period of 2 hours. Increases in response times were accompanied by changes in both stimulus locked and response locked activity. These effects were greatest over frontal scalp. In the second study subjects performed a simulated train-driving task, over a period of 4 hours. A 10 minute break was taken at the midpoint. ERPs associated with control interactions, and responses to warning tones will be presented and discussed within an overall model of mental fatigue.
This work was funded by the Human Science Domain of the UK Ministry of Defence Scientific Research Programme.