The effects of flicker on the perception of figure and ground.

Abstract

Flickering areas of the visual field are perceived predominantly as backgrounds and the adjacent nonflickering areas are seen as figures. The effect of flicker on anchoring a region as ground is optimal within a limited range of temporal frequencies. Within the temporal frequencies used in the present experiments, the effect was greatest at 6.3 and 8.3 Hz. At these flicker rates the flickering regions were seen as ground over 75% of the time, whereas at 1.4 and 12.5 Hz the flickering regions were seen as ground less than 60% of the time. The average temporal luminance of the flickering and nonflickering areas was kept equal, so the figure-ground perception we found is not due to any luminance differences between the two regions. The flickering areas seen as ground were also perceived to lie on a depth plane behind the nonflickering figure regions. The amount of perceived depth separation increased as the regions became more perceptually anchored. The temporal tuning function offlicker-induced ground appears to be similar to those of visual pathways most sensitive to high temporal frequency.