As you can see, in both Japanese prints and Art Nouveau, they both use or have resemblances of nature and geometry. There is a sense of color and movement.
Once again, this evolved into something more. More color was wanted and added to these pieces. To create an even bigger impact and intensity, vibrating colors were used. In the image to the left, with the use of geometry and colors, the image appears to be moving even though it really is not. These pieces are often referred to as non-relational pieces as well. Why? Non-relational pieces are just as they sound - they are not related to anything, have no real purpose or subject. They are art for the sake of art.
With the play of color and the knowledge of the eye, Max Wertheimer and two other psychologist formed the Gestalt theory. One image having two different appearances depending on looking at negative or positive space created quite an interest.