An EEG Analysis of the Effects of Color and Ceiling Height on the Perceived Restorativeness of Users-Focused on Indoor Common Spaces of Educational Facilities

Intentionally involving color and factoring ceiling heights in the design aspect of public spaces such as educational facilities, carries with it a potential to contribute to the emotional recovery of ordinary individuals. This study analyzes the restorative effect of color and ceiling height in 50 participants through EEG measurements. They were divided into two groups where a quasi-experiment was performed to measure relative alpha and beta waves and perceived restorativeness (PR) while viewing four 3D images of indoor lounge spaces on college campuses. Group A was assigned soft tones with low saturation and high brightness, most associated with having a positive effect on recovery. Group B was assigned vivid tones with high saturation and medium brightness, most associated with having a negative effect on recovery. The results indicated that group A experienced a restorative effect in both EEG and PR unlike group B. Higher relative alpha and lower relative beta were observed in cool colors over warm ones, and noticeable in spaces with high ceilings rather than with low ones, indicating a relaxed state with higher restorativeness. Based on this study, it was confirmed that ceiling height takes precedence over color; spaces with high ceilings and cool colors are helpful for recovery and relaxation purposes. In addition, higher relative beta was observed in warm colors with medium brightness and high saturation with a high ceiling, indicative of arousal. However, this response was restricted to EEG results, making it necessary to consider the physiological response of users during spatial evaluation.