PRIMACY OF DIMENSIONS IN COLOR-PERCEPTION

In this study, we used a procedure called selective/divided rotation t o investigate the role of dimensions in the perception of color. Ss pe rformed either selective-attention or divided-attention tasks to paire d dimensions created from each of 3 orientations of axes in color spac e: 0-degrees, 22.5-degrees, and 45-degrees. We evaluated a Euclidean h ypothesis, namely, that speeded classification of interacting dimensio ns is invariant to rigid rotation of stimulus axes. All experiments ob tained evidence against this Euclidean hypothesis. Experiments 1 to 4 showed that selective attention was best at the orientation correspond ing to saturation and brightness, suggesting primacy of these dimensio ns. The results were replicated with the pairs hue-saturation (Experim ent 7) and hue-brightness (Experiment 8). We conclude that interacting dimensions can be primary and that dimensional primacy characterizes much of perceptual experience.