The idea of figure and ground was first posited by a Danish psychologist in the early 1900s. He used a simple cardboard cutout to test whether people see the central image or whatever is around it. We now know the experiment as the drawing that can be seen as a white vase if you look at the middle of the image, or as two black faces in profile if you focus on the periphery. The model of perception was useful to psychologists, who were attempting to understand how the brain identifies and remembers things.
