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Sarina Hui-Lin, Kevin W. Bronson-Castain; Lightness constancy in 4-month-old infants: With and without a white anchoring point cue. Journal of Vision 2002;2(10):49. doi: https://doi.org/10.1167/2.10.49.
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© ARVO (1962-2015); The Authors (2016-present)
Purpose. In adult literature, lightness constancy tends to breakdown when a white anchoring point is absent. Using real surfaces and real illuminants, Chien & Teller. (OSA 2001) reported that 4-month-old infants exhibit lightness constancy tested with a white background. Our present goal is to test whether infants show a reduced constancy when a white anchoring point cue is unavailable.
Methods. The Forced-choice Novelty Preference technique was used to measure infants' novelty responses. The apparatus was a 24″′ 30″ ′ 24″ (L′H′D) testing chamber with a front 12″ ′12″ viewing window. The stimuli were real papers (Color-Aid grey series) of different reflectance (60% (light grey) and 20% (dark grey)), and were patterned as square smiley faces. The background reflectance was either 90% (white) in the white background (full cue) experiment, or 5 % (black) in the black background (no-anchoring cue) experiment. Two incandescent illuminants differing by about a factor of 3 were used. In the familiarization phase of each trial, infants were exposed to two identical smiley faces under one illumination. In the test phase, the illumination was either increased or decreased. The infant was presented one smiley face that had the same reflectance but with a novel luminance and another smiley face with a novel reflectance but the same luminance. If a white anchoring cue is important, we expect to see that infants show consistent preferences to the novel reflectance in the white background experiment, and no consistent preferences in the black background experiment.
Results. In the white background experiment, infants looked more at the face with a novel reflectance (i.e. reflectance-matched face was seen as familiar), suggesting the presence of lightness constancy. In the black background condition, infants looked equally frequently at both faces (as if both faces appeared novel), suggesting a reduced constancy.
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