Effects of color scheme and visual fatigue on visual search performance and perceptions under vibration conditions

Visual search represents one of the most encountered human-computer interaction tasks. However, the effect of visual fatigue on visual search, especially in conditions involving vibrations, remains largely known. The objective of this study was to assess the effects of color scheme and visual fatigue on visual search performance and perceptions in different vibration conditions. We conducted an experiment in which 24 participants performed four visual-search tasks involving different numbers of targets. Each search task was based on a three-way (2 x 3 x 24) within-subjects design that comprised two visual-fatigue statuses (high and low visual fatigue), three vibration conditions (static, fore-and-aft, and lateral vibration), and 24 color schemes for the visual search interfaces. The outcomes were visual search performance (i.e., task completion time and accuracy), perceptions (i.e., mental workload, perceived task difficulty, and discomfort), and user preference. Visual fatigue and color schemes significantly affected task completion time in all four visual search tasks (p < 0.05) but only partially influenced accuracy in certain tasks. The vibration condition did not affect task completion time and accuracy in any task. Visual fatigue and vibration significantly affected mental workload and perceived task difficulty (p < 0.001). Discomfort was affected only by visual fatigue (p = 0.001) but not affected by vibration. White-on-black and yellow-on-black were the preferred color schemes in the high visual fatigue and low visual fatigue conditions, respectively (p < 0.05). The findings have practical implications for the design of human-computer interfaces in conditions involving vibrations and visual fatigue. (250 words)