Abstract
The objective of this study is to evaluate the effect of daily repetitive mental workload on physiological indices. Especially, the index derived from the nasal skin temperature(NST) measured by the infrared thermography was focused. The NST was the physiological index representing the sympathetic nervous system activity. The NST declines with the sympathetic nervous system's activation. The mental workload causes sympathetic nervous system's activation, so the mental workload can be measured by NST as a declining temperature. We have found that the relationship between the amount of mental workload and the NST declining under time pressure, even more complex stimuli. However, there's no study on evaluating the NST measured for the repetitive mental workload for certain period of time. In this paper, the NST and other physiological indices, which were Fmθ wave component of Electroencephalograms(EEG) and high frequency component(HF) of R-wave interval time series of Electrocardiograms(ECG) were serially measured and evaluated on repetitive mental workload. Significant difference was found between those NST indices in each experiment by paired t-test. A stability of NST as an evaluation index for MWL was proved.