Vanishing Girls, Mysterious Blacks

Participants had to indicate the location of points on what might be called "amodal contours" in some works of art. The works represented mutually quite different cases. In one case, there were not even scattered modal cues, thus the amodal contour had to be hallucinated on the basis of generic familiarity. Here, observers indicated coherent geometrical structures (to a good approximation a smooth curve), although at idiosyncratic locations. In another case, we presented an ambiguous image that led to much more "fuzzy" amodal completions. We also presented an image that had at least some similarity to a configuration treated by Kanizsa. Here, observers were coherent and they mutually agreed, so the scarce modal cues apparently largely dictated the awareness.