Ard shape, and had a horizontal thickness of 9 pixels (0.22 deg). The dimensions of the relatable and non-relatable standard shapes are shown in Figure 2. The support ratio, which is the visible edge length divided by the total edge length (Shipley Kellman, 1992) was 0.25 for the oblique contours of the standard shapes. A modest support ratio was chosen to increase the chances of finding cogniti