Effect of changes in indoor thermal factors and task difficulty on psychophysiological indices

Indoor thermal quality affects the conditions of the occupant who is doing tasks in an indoor environment, and also task performance. Therefore, appropriate control of thermal factors is important to improve the conditions of occupant, such as thermal comfort sensation and the arousal level which is related to task performance. In order to determine guidelines how to control the thermal factors for improving the comfort sensation and arousal level, it is necessary to evaluate the condition of occupant by using quantitative and continuously measurable indices such as physiological indices. In this study, we aimed to clarify the relationship between the condition of occupant and physiological indices which is affected by changes in thermal factor and task level. We measured subjective evaluation and physiological indices such as electroencephalogram (EEG), electrocardiogram (ECG), respiration, and skin temperature of 10 participants in 4 experimental conditions consisted of different temperature and arithmetic task level. From the result of time-series analysis and correlation analysis among the experimental conditions, the subjective evaluation value, and physiological indices, it is showed that difference of task level can affect to the correlation between the conditions of occupant and physiological indices. These result suggests that the effect of task level on physiological indices should be considered in order to evaluate the conditions of occupant by using physiological indices.