Abstract
Previous study studies have demonstrated 4-month-old infants have color constancy. However, these studies did not control the luminance contrasts precisely. To solve this problem, we presented stimuli in which luminance cues are eliminated, and tested the infant's color constancy more precisely.
In the study of color constancy, it is important to exclude the possible luminance artifacts. We first obtained subjective isoluminance in each infant by using the minimum motion paradigm (Maurer, Lewis, Cavanagh & Anstis, 1989), and used these data to control the luminance in the stimuli.
We used a familiarization paradigm in the present study. In the familiarization phase, two identical face-like patterns were presented side by side. They were surrounded by small patches of various colors. Such a Mondrian-like pattern is expected to improve the performance of color constancy. The colors of face-like pattern and patches were simulating OSA color chips, based on spectrophotometric data. In the test phase, the chromaticity of the whole pattern changed to simulate illuminant-color changes, except either of the face-like pattern, which was presented with the same chromaticity as in the familiarization phase. If infants have color constancy, they would attribute it to changes in illumination, and the face-like pattern with chromaticity change may appear as a novel object surface. We controlled the intensity of illuminant to prevent changes in luminance of the two face-like patterns, so that the infants could not use the luminance contrast as a clue to discriminate two face-like patterns. If color constancy is present in infants, they will show a preference to the non-change pattern, which seemed to appear as a novel object surface under a novel illumination.
Current results suggested that the 4–5-month-old infants had a significant preference for the non-change face-like pattern. This result suggests that the 4–5-month-old infants have the color constancy.
Acknowledgements: This research was supported by PRESTO (Japan Science and Technology Agency) and a Grant-in-Aid for Scientific Research (18300090, 20119002) from Japan Society for the Promotion of Science.