Variation of chromatic sensitivity across the life span

Thresholds were measured along three directions in color space for detectin g an equiluminant color change of a set of bars embedded in a larger field of spatio-temporal achromatic noise for observers ranging in age from 3 mon ths to 86 years. Pre-verbal observers were assessed with a forced-choice pr eferential-looking technique while older observers responded orally or manu ally. Over the life span, thresholds could be described along each color ax is tested by a curve with two trends. Thresholds decreased with each doubli ng of age by nearly a factor of two until adolescence. Thereafter, threshol ds increased by a factor of 1.4-2 with each doubling of age. Sensitivity to chromatic differences varied similarly along all three axes tested, sugges ting uniformity in the sensitivity of chromatic mechanisms across the life span. (C) 2000 Elsevier Science Ltd. All rights reserved.