ABSTRACT
Edwin Holt was an early proponent of a form of realism that holds that the perceptual world corresponds to invariant aspects of the physical world. This chapter explains the idea by introducing many variants of the contrast asynchrony principle. The primary idea to be gleaned from these visual displays is that perceived grouping can be determined by second-order information in the image even though the elements of the image have a similar first-order appearance. That is, the contrast asynchrony demonstrates that people often report a sensitivity to the first-order information when they are really demonstrating sensitivity to the second-order information. The chapter examines the contrast and spatial scale in "weaves," a variant of the Hermann Grid illusion. It suggests that in order to understand the organization of the displays, a more sophisticated understanding of the physical stimulus is required, an idea not out of line with Holt's general worldview.
