Mental fatigue and task performance
The impact of work on task performance and on the health of employees has received a lot of attention over the past decades. This seems to be justified by the number of workers that are assessed as work disabled on mental grounds. In the Netherlands,, for example, one in every three work disability benefit recipients receives a diagnosis of this kind. In addition, mental fatigue might have important consequences for cognitive functioning. It is known that especially under conditions of high demand on the information processing system, human performance is prone to failures or inaccuracies. These phenomena are of special importance, since they might lead to accidents
In general, workers use different methods to protect the information processing system from overload. For example, working hours are punctuated by short rest periods, that is, coffee breaks and pauses for lunch. To further prevent performance against deterioration due to increasing levels of mental fatigue, we all use stimulants in the form of a cup of coffee or tea. Additionally, the information processing system itself has several very specific built in mechanisms to protect the system against overload. For instance, not all the information provided by the environment reaches the level of consciousness and is processed in a controlled and effortful mode.