Fiorentini A, Porciatti V, Morrone M C, Burr D C
Dipartimento di Psicologia, Università di Roma, La Sapienza, Italy.
Vision Res. 1996 Nov;36(21):3557-66. doi: 10.1016/0042-6989(96)00032-6.
We have investigated whether ageing affects selectively the responses to equiluminant patterns of pure colour contrast. In two groups of subjects (mean ages 29 and 72 yr) contrast thresholds were measured psychophysically for the detection and for the discrimination of the direction of motion of drifting gratings. The gratings were modulated either in pure luminance contrast (and uniform colour), or pure chromatic contrast (red-green equiluminant gratings). In subjects of the same age groups, visual evoked potentials (VEP) were recorded in response to gratings with either pure luminance contrast or pure colour contrast sinusoidally reversed in contrast at various temporal frequencies. It was shown that psychophysical contrast sensitivity for equiluminant patterns deteriorates significantly with age, and VEP latency increases. However, these effects of ageing on the responses to patterns of pure colour contrast are substantially the same as those observed in the same subjects for stimuli with pure luminance contrast. The results suggest that ageing causes a small and unspecific decline of the response of the visual system to luminance and colour contrast.
我们研究了衰老是否会选择性地影响对纯色对比度等亮度图案的反应。在两组受试者（平均年龄分别为29岁和72岁）中，通过心理物理学方法测量了检测和辨别漂移光栅运动方向的对比度阈值。光栅以纯亮度对比度（和均匀颜色）或纯颜色对比度（红-绿等亮度光栅）进行调制。在同一年龄组的受试者中，记录了视觉诱发电位（VEP），以响应在不同时间频率下对比度呈正弦反转的纯亮度对比度或纯颜色对比度的光栅。结果表明，等亮度图案的心理物理学对比度敏感性会随着年龄的增长而显著下降，VEP潜伏期会增加。然而，衰老对纯色对比度图案反应的这些影响与在相同受试者中观察到的对纯亮度对比度刺激的影响基本相同。结果表明，衰老会导致视觉系统对亮度和颜色对比度的反应出现轻微且非特异性的下降。
