Thresholds for color discrimination in English and Korean speakers

摘要

Categorical perception (CP) is said to occur when a continuum of equally spaced physicalchanges is perceived as unequally spaced as a function of category membership (Hamad,S. (Ed.) (1987). Psychophysical and cognitive aspects of categorical perception: A criticaloverview. Cambridge: Cambridge University Press). A common suggestion is that CP forcolor arises because perception is qualitatively distorted when we learn to categorize adimension. Contrary to this view, we here report that English speakers show no evidenceof lowered discrimination thresholds at the boundaries between blue and green categorieseven though CP is found at these boundaries in a supra-threshold task. Furthermore, thereis no evidence of different discrimination thresholds between individuals from two lan-guage groups (English and Korean) who use different color terminology in the blue-greenregion and have different supra-threshold boundaries. Our participants' just noticeable dif-ference (JND) thresholds suggest that they retain a smooth continuum of perceptual spacethat is not warped by stretching at category boundaries or by within-category compres-sion. At least for the domain of color, categorical perception appears to be a categorical,but not a perceptual phenomenon.