Rubin's vase ("The Two Face, One Vase Illusion")

Gestalt principles "Figure-Ground" model Figure-ground perception was first discovered by Edgar Rubin in 1915. Though Rubin never really considered himself a Gestalt psychologist, his work with figure-ground perception was embraced by its founders and led to the development of a major Gestalt law. According to this phenomenon, when we perceive a visual image, we tend to simplify it by separating it into figure and ground. The figure is the object you perceive. The ground is everything in the background. So if in the image above you saw a white circle, the circle is the figure and the surrounding black space is the background.