Abstract
At last year’s VSS we presented the Binding Ring Illusion (McCarthy, Kupitz and Caplovitz, 2011) revealing the size of a circular array is subject to assimilation processes. The Binding Ring experiments revealed the outer edges of the array elements serve as a boundary for this assimilation. Is the perceived size of a circular array dictated by this same outer edge? Experiment 1 examined how array element size influences the array’s perceived size. Experiment 2 examined how the orientation of triangular elements influences an array’s perceived size. Experiment 3 examined the perceived size of circular outlines made of differing outline thicknesses. Results: the size of the array elements has no influence on the perceived size of the array itself. This suggests that either the midpoint or center of gravity of the elements is used as a reference point for constructing the perceived size of the array. The results of the second experiment demonstrated that it is the center of gravity and not the midpoint of the elements that is used. In contrast, when the sizes of two explicitly defined circles are compared, one with a thick outline and one with a thin outline, subjects match the sizes based on the radius of the inner edge of the circles and not the center of the outline contour. Conclusions: the outer edge of a circular array that serves as a boundary for assimilation in the Binding Ring Illusion is not the cue used to construct the perceived size of the array itself. Instead, the perceived size of a circular array is based on the distance between the center of the array and the center of gravity of the array elements. In contrast, the perceived sizes of circular outlines are based on on the center of the outlines but rather their inner radius.
Meeting abstract presented at VSS 2012