Experimental investigation about effect of emotion state on people's thermal comfort

Abstract

Emotion affects people's cognition, perception and reaction to the outside world. The psychological and physiological changes brought by different emotion states may have some impact on people's perception to thermal environment. The objective of this study is to investigate whether emotion state would have some influence on people's thermal perception and comfort. In this study, experiments were carried out. Eighteen college students were recruited in the experiments. Their emotion states were induced to be joyful (positive) or boring (negative) by watching videos which would arouse intended negative or positive emotions. There was no emotion induction for neutral state. The experiments were conducted in three temperature conditions (21°C, 24°C and 27°C) and three activity levels (sitting, standing and exercising). Subjective questionnaires about participants’ emotion state, thermal sensation, thermal comfort, thermal expectation and thermal environment satisfaction were collected. Physiological parameters were measured including skin temperature, heart rate, blood pressure and heart rate variability. The results showed that emotion state affected thermal perception and comfort only while sitting and standing and not during exercise. For the two light activities, subjects’ thermal comfort vote for boring emotion was significantly higher than that of joyful and neutral state, which meant that subjects’ felt less comfortable under boring emotion. The thermal sensation vote of boring emotion became higher. Participants tended to be warmer in boring emotion state. The results about thermal satisfaction vote and thermal expectation also indicated that the evaluation gets worse in boring state. The analysis of physiological parameters showed that, in light activities, both systolic blood pressure and heart rate increased under boring state compared to neutral and joyful state. The heart rate variability index (LF/HF) was higher under boring state and lower under joyful state than that of neutral state. Both systolic pressure and heart rate were found to be positively correlated with thermal sensation vote in different emotion states, while higher LF/HF was related to less thermal comfort conditions. During exercising, subjective questionnaires and physiological parameters did not change significantly with different emotion states.