Within-texture collinearity improves human texture segmentation

Spatial arrangement has been shown to facilitate both detection of a threshold target by collinear flankers and detection of smooth chains within random arrays of suprathreshold elements. Here, we investigate the effect of alignment between texture elements on orientation-based texture segmentation. Textures composed of Gabor elements were used in a figure-discrimination task. The degree of collinearity within the texture was manipulated, and threshold figure-ground orientation differences found. A facilitative effect of collinearity on segmentation was seen, which was insensitive to Gabor carrier phase at the texture-element co-axial spacing of 3lambda used here. The pattern of results with respect to collinearity could not be attributed simply to improved linkage of local orientation contrast at figure borders in isolation, and instead suggests a role for the figure interior in texture segmentation.