Abstract
A cue to understand individual differences of driver's mental fatigue is required from a viewpoint of better relationship between human and machine in driver support system. From Pavlov's and Eysenck's theory, it is suggested that there are some response types to stimulus in brain, which have relationship with fatigue and appear as a personality of introversion-extraversion. First, the stimulus response types were examined in an experiment with visual stimulus. As a result of brain waves analysis, extraversion corresponded to “excitation type” in which alpha wave frequency increased with the stimulus presentation, and introversion corresponded to “inhibition type” in which its frequency showed phasic decrease before increase. Next, the following model was assumed : mental fatigue (depression of brain activity) after task may be affected by interaction between introversion-extraversion (corresponding to stimulus response type) and mental task load (corresponding to stimulus). From analyses of alpha wave frequency, psychological state and standard deviation of reaction time in a simulated driving task experiment, it was thought that mental fatigue after the task was larger in extraverts than in introverts in the task with lower load and was lager in introverts in the higher load task. This result may support validity of the interaction model.
