Figure 2.

Crowding and flipping demo. The Bouma law mk 2 says that, for any given location and direction in the visual field, critical spacing, measured between the centers of the target and the flankers, is conserved. Thus, crowding should be unaffected by any change that does not affect center-to-center spacing, such as flipping an object about its center. Here we present a demo that appears to contradict this law. In each test row, we will ask you to identify a target. The bottom row shows you all six possible targets. In the first and second rows, while fixating the plus sign on the right, try to identify the target (the middle object). Identifying is hard when the jagged (feature-rich) edge of the flanker is near to the target (first row) and easier when it is far (second row) even though center-to-center spacing (and the set of features) is unchanged. This breaks the Bouma law mk 2. Crowding seems to depend specifically on the distance of the jagged edge of the flanker, not the distance of the flanker itself, from the target.