The Importance of Psychophysiological Factors in Comfort Studies

In the last years the concept of comfort is changed. Recent findings underline the role of physiological and psychological processes in determining the perception of individual’s comfort. Comfort has been traditionally measured in terms of physiological reactivity during the exposure to an environmental stimulus. In experimental studies, the activity of the autonomous nervous system is assessed by measuring Heart Rate Variability (HRV), while participants are exposed to the stimulation. The increase of the activity of the sympathetic nervous system and the decrease of the response of the parasympathetic nervous systems are considered indices of a stress (discomfort) response. Interestingly, recent studies have shown that the response to the stressor is also influenced by psychological processes. It has been found that the response of the autonomous nervous system changed as a function of the mood states, personal believes and personality traits of the participants. Although these results suggest the importance to evaluate both physiological and psychological variables, standards and technical guidelines for supporting comfort design are still based only on the definition of the physical parameters of the environmental stressors. This short communication examines the recent results concerning the role of psychological and physiological processes in comfort perception, showing the necessity to reduce the gap that exists between engineering research and findings of the current psychophysiological research.