PERCEIVED TEXTURE SEGREGATION IN CHROMATIC ELEMENT-ARRANGEMENT PATTERNS - HIGH-INTENSITY INTERFERENCE

An element-arrangement pattern is composed of two types of elements th at differ in the ways in which they are arranged in different regions of the pattern. We report experiments on the perceived segregation of chromatic element-arrangement patterns composed of equal-size red and blue squares as the luminances of the surround, the interspaces and th e background (surround plus interspaces) are varied. Perceived segrega tion was markedly reduced by increasing the luminance of the interspac es. Perceived segregation was approximately constant for constant rati os of interspace luminance to square luminance and increased with the contrast ratio of the squares. Unlike achromatic element-arrangement p atterns composed of squares differing in lightness [Beck et al (1991). Vision Research, 32, 719-743] perceived segregation did not decrease when the luminance of the interspaces was below that of the squares. S imilar results were obtained for red and yellow, red and green, green and yellow, green and blue, and blue and yellow squares, Perceived seg regation based on edge alignment was not interfered with by high inten sity interspaces. Stereoscopic cues that caused the squares composing the element-arrangement pattern to be seen in front of the interspaces did not greatly improve perceived segregation. One explanation of the results is in terms of inhibitory interactions among achromatic and c hromatic cortical cells tuned to spatial frequency and orientation. Al ternately, the results may be explained in terms of how the luminance of the interspaces affects the grouping of the squares for encoding su rface representations. Neither explanation accounts fully for the data and both mechanisms may be involved. Copyright (C) 1996 Elsevier Scie nce Ltd.