Mental Fatigue Measurement Using EEG

1.1 Background We live in a highly technological and information-oriented society. The use of computers in modern society is omnipresent. They are used for innumerable applications in various sizes and forms. Over the past 20 years, the personal computer has become widely used, both in the office and at home. People use computers to write documents, maintain databases, manage finances, draw diagrams and graphics, make presentations, compile mailing lists, search computer databases, write application programs, use the Internet, and myriad other tasks. Since such work requires prolonged vigilance and mental activity with sedentary work, fatigue caused from visual display terminal(VDT) tasks frequently occurs in the workplace. Fatigue is a major, but usually neglected, factor that increases the occurrence of performance errors and lapses. Fatigue, especially mental fatigue, is inevitable for office workers and in life in general. Fatigue is usually related to a loss of efficiency and disinclination to effort. It is also possible that cumulative mental fatigue leads to decreased productivity in the workplace and induces critical errors in the worst cases. Many experimental studies have demonstrated that mental fatigue induces deterioration in cognitive functions. Responses become slower, more variable, and more error prone after mental fatigue (Scheffers et al., 1999; Dorrian et al., 2000; Smith et al., 2002). The importance of adequate fatigue monitoring could be demonstrated by the Exxon Valdez oil tanker accident. The direct cause of this, America’s worst oil spill, was a human performance error, which had been observed and cautioned about before; however, the warning had arrived too late in order to remedy the situation because the severely fatigued mate did not immediately respond to the warning (Dement and Vaughan, 1999). Deficits in perceptual processes after extended wakefulness are responsible for performance deficits. Mental fatigue refers to the effects that people may experience after or during prolonged periods of cognitive activity. In this sense, it is a very common phenomenon in everyday modern life. Therefore, the management of mental fatigue is important from the viewpoint of occupational risk management, productivity, and occupational health.