B

Anomalous surfaces

Anomalous squares are supported by the collinear borders of truncated disks. The direction of truncation determines whether the square appears as a foreground figure (as in Anomalous square in the foreground) or as an aperture in the surrounding anomalous surface (Anomalous square as a hole). In both cases the brightnesses of the square region and its surround appear different, with color in the foreground always more pronounced than in the background. Clocks (1 and 2) are the artistic transposition of the phenomenon discovered in the scientific domain. Here, black disks are replaced by radial textures that Kanizsa generated by rotating the canvas while maintaining constant his microbrushstrokes. The Anomalous squares emerge also when the inducer-background contrast is inverted (see negative images of Anomalous square in the foreground and Anomalous square as a hole).