Shinomori K, Schefrin B E, Werner J S
Department of Information Systems Engineering, Kochi University of Technology, Japan.
J Opt Soc Am A Opt Image Sci Vis. 2001 Feb;18(2):310-8. doi: 10.1364/josaa.18.000310.
Wavelength discrimination functions (420 to 620-650 nm) were measured for four younger (mean 30.9 years) and four older (mean 72.5 years) observers. Stimuli consisted of individually determined isoluminant monochromatic lights (10 Td) presented in each half of a 2 degrees circular bipartite field with use of a Maxwellian-view optical system. A spatial two-alternative forced-choice method was used in combination with a staircase procedure to determine discrimination thresholds across the spectrum. Small but consistent elevations in discrimination thresholds were found for older compared with younger observers. Because the retinal illuminance of the stimuli was equated across all observers, these age-related losses in discrimination are attributable to neural changes. Analyses of these data reveal a significant change in Weber fraction across adulthood for a chromatically opponent pathway receiving primarily antagonistic signals from middle-wavelength-sensitive and long-wavelength-sensitive cones but not for a short-wavelength-sensitive cone pathway.
对4名年轻观察者（平均年龄30.9岁）和4名年长观察者（平均年龄72.5岁）测量了波长辨别函数（420至620 - 650纳米）。刺激物由使用麦克斯韦观察光学系统在2度圆形二分视野的每一半中呈现的单独确定的等亮度单色光（10特罗兰）组成。采用空间二选一强制选择法并结合阶梯程序来确定整个光谱的辨别阈值。与年轻观察者相比，年长观察者的辨别阈值有小幅但一致的升高。由于所有观察者的刺激物视网膜照度相等，这些与年龄相关的辨别能力损失归因于神经变化。对这些数据的分析表明，在成年期，对于主要接收来自中波敏感和长波敏感视锥细胞的拮抗信号的色拮抗通路，韦伯分数有显著变化，但对于短波敏感视锥细胞通路则没有。
