Several studies aimed at evaluating intellectual productivity and specially
designed tasks were given. However, the result may not be reflected the actual intellectual
productivity because the designed tasks are different from office works. Meanwhile,
there are two mental states (work and temporary rest state) in office workers which are
changing alternatively during mental work. If the mental states of the workers can be
detected, the productivity can be measured more accurately. In this study, the authors
aimed at developing a detection method of temporary rest state while performing mental
works by measuring physiological indices such as EEG, ECG, and EMG of extraocular
muscles and orbicularis oculi muscle. From these measured indices, the authors extracted
6 features which were alpha and beta brain waves, low and high frequency waves of heart
rate, and the intervals of eye blink and saccade eye movement. They were used to detect
a temporary rest state by using Mahalanobis Discrimination Analysis. As a result of
the subject experiment, it was found that the detection accuracy was 80.2%. This result
shows the possibility to use the physiological indices as one of the mental state detection
methods