Study on Physiological Responses to Color Stimulation

Recently, many areas including design have been evolving from being conventionally function‐oriented to being sensibility‐oriented, and this trend has prompted an increase in the importance of sensory stimulation. Among various elements that stimulate human senses and satisfy sensibility, color is directly influenced by human sensibility and is the primary visual simulation emanating from objects. While previous research on color and sensibility has typically used a qualitative evaluation, the purpose of this present study is to examine quantitative color design through a more systematic and scientific color design approach. For this purpose, we applied systematic analysis through the subjective evaluation of sensibility and the objective evaluation of the biosignal response, and quantitatively assessed how human sensibility responds to color and each color image. The experiment was conducted with 30 healthy male and female adults in a color room (4×3.5×2.5m) of six different colors – red, orange, yellow, green, blue and purple – and biosignals were measured such as heart rate variability (HRV), blood pressure, intraocular pressure, and body temperature, while color stimulation was applied for 5 minutes. Subjective sensibility was measured on the 7‐point scale of the SD method before and after the experiment using 20 emotional adjectives extracted through the KJ method, and the results were analyzed objectively. Professional papers and previous works state that, universally, warm colors help to activate the sympathetic nerve system, while cold colors affect the parasympathetic nerve system. However, this experiment shows that by adjusting color luminosities to fit preferred levels of individual test subjects rather than using the typical color luminosities and stimulating with the adjusted colors, warm colors do positively affect the parasympathetic nerve system to calm the body and mind through the emotional adjective evaluation and the physiological signal measurement evaluation. This means that physiological and psychological reactions from colors can be assessed differently through the preferred color or luminosity of the user. In addition, intraocular pressure, blood pressure, and body temperature also showed significant differences between before and after color stimulation. In the evaluation of subjective sensibility, the analysis of emotional adjectives was consistent with the objective evaluation of biosignal before and after color stimulation, and the results differed among the colors.