Effects of speed, motion type, and stimulus size on dynamic visual search: A study of radar human-machine interface

Human visual perception behavior in dynamic environments could be affected by the motion properties of stimuli. The purpose of this study was to investigate the effects of motion type, size, and speed of stimulus on visual search performance and visual comfort in both single-and double-target tasks. Twenty participants attended an experiment in which they finished two tasks at three speeds (low, medium, and high), in two motion types (flicker, uniform), with varied levels of stimulus size (small, medium, and large) on a display. The search time, accuracy, critical flicker frequency, visual comfort, and cognitive load were recorded to provide a comprehensive understanding of participants' visual preferences during the experiment. The results indicated the increasing speed would weaken participants performance on visual search tasks; Medium-sized stimuli were recommended considering search efficiency and cost-effectiveness; More impor-tantly, the present study also found that flicker motion led to better task performance in the low-speed task, due to increased alertness and lead physiological arousal effects, which may imply the past studies have overstated the negative effects of flickering in dynamic environments.