Mid-air Image's Background Changes the Impression of a Mid-air Image

Abstract

Previous research in perceptual science has shown that peripheral information can easily change the perception of an object. However, mid-air images are rarely used as targets in such studies. In this study, we placed the ground below a mid-air image and investigated how changing the ground image affected the perception of the mid-air image. Specifically, we confirmed through psychophysical experiments that shadow length variation changes depth perception (Experiment 1) and that the relative motion of a mid-air image and the ground image changes speed perception (Experiment 2). The results of Experiment 1 showed that increasing the shadow length from its exact value increased the perceived depth of the mid-air image by 16% while decreasing the shadow length from its exact value decreased the perceived depth of the mid-air image by 26%. The results of Experiment 2 showed that the perceived speed of the mid-air image when the ground was moving in the opposite direction of the mid-air image was 58% faster than the perceived speed when the ground was moving in the same direction. We expect that the grounds created in this study can extend the range of depth and speed perception in content designs using mid-air images.