Deterioration of Visibility of Scrolling Text Presented Nearby Image Moving in the Opposite Direction

Abstract

We investigate the visibility of scrolling text presented nearby a dynamically moving image. In two experiments, we evaluate the subjective speed and readability of scrolled fake addresses presented immediately above a moving grating pattern that covers a large part of the visual field. The drift speed and direction of the grating were controlled to reveal the visibility of the text. The results show that the scrolling addresses exhibited slower subjective speed and better readability when the grating moved in the same direction as the scrolling addresses. On the contrary, faster subjective speed and worse readability of the scrolling addresses were raised by the grating moving in the opposite direction. The strength of these effects was dependent on the speed difference between the scrolling addresses and the grating. These results suggest that the visibility of the scrolling text, assessed in terms of subjective speed and readability, strongly depends on nearby moving images.