Information integration study of Metelli's and Morinaga's theories of achromatic transparency

Abstract

Information integration methodology was used to test Metelli's and Morinaga's theories of achromatic transparency. Stimuli were transparent achromatic disks on a background formed by two adjacent horizontal rectangles. The common border of these rectangles divided each disk in two halves. L et P and Q be the luminances of the left and right halves of a disk and let A and B be those of the left and right rect- angles, respectively. Transparency is given by the ratio (P - Q) / ( A - B) in Metelli's theory and is given by a weighted average of the ratios ( P - Q) / ( A - Q) and (P - Q) / ( P - B) in Morinaga's theory. Participants rated the transparency of disks with A and B fixed and P and Q combined factorially. Morinaga's theory closely predicted the obtained patterns of factorial curves and Metelli's theory predicted them incorrectly. Morina ga's theory could also account well for individual diffe rences in the ratings of transparency. The results support the general idea that transparency depends on the integration of luminance information rather than on the integration of lightness information. In everyday life we often see objects through transparent media. This fact raises two basic problems: that of quantifying the subjective visibility of objects seen through transparency and that of specifying the operations of integration of luminance information that generate this visibility. Anderson's (1981, 1982, 1996, 2008) information integration theory provides a solution for the problem of quantification and a methodology for the specification of integration operations. The present study used Anderson's information integration methodology to test Metelli's and Morinaga's theories of achromatic transparency.