Abstract
Color constancy – the ability to judge surfaces as having an unchanging reflectance under changing illuminations – is necessary for stable object recognition. Whilst many studies have investigated color constancy in adults, its developmental trajectory remains unknown. Here we ask whether daylight illumination priors, proposed to aid constancy, might depend on learning through experience. To study the development of color constancy, and use of daylight priors in childhood, we created a novel child-friendly color-matching task.
Fifty-two adults and 65 6-11 year-old children saw a dragon’s favorite colored sweet under a neutral illumination (D57). On the other side of the display, they picked a match from an array of eight sweets, containing a reflectance match (color constant) and a tristimulus match (color inconstant) under either a blueish/yellowish illuminant (typical daylights), or reddish/greenish illuminant (atypical daylights). Experiment 1 used 2D patches, whereas Experiment 2 used more realistic 3D rendered objects.
In Experiment 1, children had significantly higher color constancy indices (CCIs) than adults (p<.001). Furthermore, CCIs decreased with age during childhood (linear regression combining all illuminants, p<.001). In Experiment 2, there was no significant overall difference between adults and children, but a smaller but significant change with age (p=.041). There was also a significant age group x illuminant interaction, in which adults had slightly lower CCIs than children under blueish, reddish, and greenish illuminants but higher under yellowish.
By 6 years of age, children have well-developed color constancy, with adult-like performance when using realistic 3D stimuli. The results of Experiment 1 are opposite to those predicted by color constancy developing during childhood, but this may be influenced in part by different strategies used by adults and children. Children’s differing pattern of performance across illuminants - including worse for yellowish - partially supports the possibility that they are still developing a daylight prior.