Color naming and categorization in inherited color vision deficiencies

Abstract

Dichromatic subjects can name colors accurately, even though they cannot discriminate among red-green hues (Jameson & Hurvich, 1978). This result is attributed to a normative language system that dichromatic observers developed by learning subtle visual cues to compensate for their impoverished color system. The present study used multidimensional scaling techniques to compare color categorization spaces of color-vision deficient (CVD) subjects to those of normal trichromat (NT) subjects, and consensus analysis estimated the normative effect of language on categorization. Subjects sorted 140 Munsell color samples in three different ways: a free sorting task (unlimited number of categories), a constrained sorting task (number of categories limited to eight), and a constrained naming task (limited to eight basic color terms). CVD color categories were comparable to those of NT subjects. For both CVD and NT subjects, a common color categorization space derived from the three tasks was well described by a three-dimensional model, with the first two dimensions corresponding to reddish-greenish and yellowish-bluish axes. However, the third axis, which was associated with an achromatic dimension in NTs, was not identified in the CVD model. Individual differences multidimensional scaling failed to reveal group differences in the sorting tasks. In contrast, the personal color naming spaces of CVD subjects exhibited a relative compression of the yellowish-bluish dimension that is inconsistent with the typical deutan-type color spaces derived from more direct measures of perceptual color judgments. As expected, the highest consensus among CVDs (77%) and NTs (82%) occurred in the naming task. The categorization behaviors studied in this experiment seemed to rely more on learning factors, and may reveal little about CVD perceptual representation of colors.

Recognition Memory for Colored and Black-and-White Scenes in Normal and Color Deficient Observers (Dichromats)

“…Another study indicated that dichromats’ performance was significantly better (i.e. more similar to normal observers’ performance) in a color-naming task using eight basic color terms (BCT: red, green, yellow, blue, brown, pink, orange, and purple) consisting of naming color samples than it was in a free sorting task [5]. Recently, Lillo et al [7] reported that when the participants’ task was to select the best example of a given BCT, there was a significant difference between dichromats and NTs only for derived colors (brown, purple, orange, pink and gray) but not for primary colors (red, green, yellow, blue, black and white).…”

Does Dichromatic Color Simulation Predict Color Identification Error Rates?

“…It is well established that dichromats often identify colors correctly (some of the time) that are on the same dichromatic line of confusion and that their use of color names does not correspond to their color discrimination ability. [13][14][15][16][17][18][19][20][21] Their use of color names depends on experience, 14,21 size of the stimuli, 15,17,20 both relative and absolute brightness differences in the stimuli, 13,14,16,18,21 and whether there are constraints placed on the color names. 14,19,20 Some of these factors are likely responsible for the error asymmetries in our results.…”

“…14,17,19,21 Exactly how they use this information appears to be dependent on the display characteristics, context, and past experience. These higher order factors mean that modeling color discrimination and identification data within linear and nonlinear color vision models will be unsatisfactory.…”

How Do Things Look to the Color-Blind?

“…One deuteranope, in particular, behaved exactly like someone with normal color vision. Bonnardel (2006) required subjects to name 140 colored chips, presented individually against a grey background in random order using eight basic color terms.…”