A Paired Comparison Analysis of Color Selectivity in Metacontrast

Abstract

In metacontrast masking of chromatic stimuli, visibility of a target stimulus is reduced by a similar-colored mask. The degree of metacontrast was measured as a function of color difference between target and mask for 8 isoluminant colors using the paired-comparison method. Color selectivity of metacontrast did not differ between cardinal (L–M or S–(L+M)) and intermediate mask colors. The width of color tuning was comparable to that predicted from linear combinations of cone outputs. These results suggest that colorselective metacontrast results from intra-channel interaction of color signals in multiple channels that combine cone signals in a linear fashion.