Kim C B, Mayer M J
Department of Psychology, University of Wisconsin-Madison 53706.
J Opt Soc Am A Opt Image Sci Vis. 1994 Jul;11(7):1958-69. doi: 10.1364/josaa.11.001958.
Foveal flicker contrast sensitivity was measured for healthy adults at temporal frequencies from 2.5 to 50 Hz. The first experiment compared two-interval forced-choice (2IFC) and yes-no detection (Y-N) testing procedures for younger (19-33-year-old) and older (67-73-year-old) observers. The 2IFC technique resulted in higher absolute estimates of sensitivity. However, within a method, relative differences were similar. Therefore the two methods gave similar estimates of temporal contrast-sensitivity change with age. Experiment 2 compared 89 observers from 18 through 77 years of age to explore the effect of the time course of aging on flicker sensitivity. The 2IFC procedure was used, and retinal illuminance changes with age were controlled. Significant overall losses in contrast sensitivity were found for the 45-54, 55-64, and 65-77-year-old age groups. Overall sensitivities for the 35-44-year-old group were comparable with or (not significantly) higher than those for the 18-24- and 25-34-year-old groups. The results suggested that (1) foveal temporal contrast sensitivity does not decline until after 44 years, (2) losses after 44 years are in amplitude but not in temporal resolution of the visual response, and (3) the mean rate of loss is approximately 0.78 decilog per decade after 44 years. These results are consistent with the existence of three phases of development of temporal contrast sensitivity over the life span. The results also emphasize the importance of including healthy-eyed age-matched controls in studies of flicker sensitivity in visual dysfunctions that affect mainly older adults.
对健康成年人在2.5至50赫兹的时间频率下测量了中央凹闪烁对比敏感度。第一个实验比较了年轻（19 - 33岁）和年长（67 - 73岁）观察者的双间隔迫选（2IFC）和是/否检测（Y - N）测试程序。2IFC技术得出的敏感度绝对估计值更高。然而，在一种方法内，相对差异是相似的。因此，这两种方法对随年龄变化的时间对比敏感度给出了相似的估计。实验2比较了89名年龄在18岁至77岁之间的观察者，以探讨衰老时间进程对闪烁敏感度的影响。使用了2IFC程序，并控制了视网膜照度随年龄的变化。发现45 - 54岁、55 - 64岁和65 - 77岁年龄组的对比敏感度总体有显著下降。35 - 44岁组的总体敏感度与18 - 24岁和25 - 34岁组相当或（无显著差异）更高。结果表明：（1）中央凹时间对比敏感度在44岁之后才开始下降；（2）44岁之后的下降是视觉反应幅度上的下降，而非时间分辨率上的下降；（3）44岁之后平均下降速率约为每十年下降0.78分贝。这些结果与时间对比敏感度在整个生命周期中存在三个发展阶段的观点一致。这些结果还强调了在主要影响老年人的视觉功能障碍的闪烁敏感度研究中纳入年龄匹配的健康对照的重要性。
