Analyzing the Impacts of Color on Aesthetic Judgment and Eye Movement Indicators of Experts and Non-experts in ArchitectureCase Study: Residential Building Façades in Tehran

The impacts of properties and design of the built environment has always been a concern for environmental psychology. Meanwhile role of façade design, as a visual effect of a building and effective way for beautification of the urban scape, is important and can be studied as emotional and eye behavior reactions of individuals. In this regard, the present study, in the field of psychophysics study, investigates "bottom-up" (color factor effect) and "top-down" (expertise factor effect) processes on eye movements during aesthetic judgment of new residential buildings in Tehran. The images are displayed in in two black-white and color modes. For this purpose, in a quantitative method of quasi-experimental design, the visual psychophysics is studied using an eye tracking tool. The eye tracker is known as a complementary tool in individuals’ cognitive processes assessment. In this study, five indicators for eye movement assessment (number of fixations, duration of fixations, duration of saccades, amplitude of saccades, and scan path) are investigated. The sampling method is voluntarily with random assignment, and the samples include 38 participants that were divided into two groups of architects (experts) and non-architects (non- experts) (21 experts and 19 women). The findings of the aesthetic judgment study show that there is a significant difference between selected images in these two groups for both color and black-white images. Architects prefer mixed materials façades while non-architects prefer the stone façades. The findings of the behavioral study also show that experts prefer images with the dominant red wavelength intensity and red / green contrast while non-experts prefer low contrast images. On the other hand, analysis of eye movement indicators and heat maps show differences in visual scanning pattern, preference for layers and facade features under the influence of "expertise" factor, rather than "color" factor. By examining static indicators, it is found that duration of fixations is influenced by expertise and architects takes more time on fixations. By a smaller number of fixations, they have higher fixations duration than non-architects in both display modes. In examining the dynamic indicators, it is also found that architects have lower scan path. On the other hand, by spending more time on observing the façade elements, the scan path length of architects is less than the non-architects. Furthermore, the non- architects tend to explore more regions in the presented image, while architects tend to focus on specific features of the image. It can also be seen that the heat maps pattern in black-white images is almost the same as the color ones, but the intensity of focus in the color images is lower. In general, the results of the study show a behavioral and cognitive difference between these two groups. Therefore, it can be concluded that the eye tracker as a complementary tool can be used for better understanding the visual impact of façades design and each of its functional indicators in human visual aesthetic perception. This can be used for evidence-based designs to optimize design solutions based on empirical evidence, scientific research, and other available information.