Aging and blur adaptation
Aging and blur adaptation
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DOI：
10.1167/7.6.8
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发表时间：
2007-01-01
影响因子：
1.8
通讯作者：
Werner, John S.
中科院分区：
文献类型：
--
作者：
Elliott, Sarah L.;Hardy, Joseph L.;Werner, John S.
尽管视网膜刺激的光谱分布发生了很大的变化，色敏感度也丧失了，但在老化的视觉系统中，颜色外观仍然非常稳定（P. B.德拉亨特，J.L.哈代，K. Okajima，& J. S. Werner，2005; J. S. Werner，1996）。这种稳定性可能反映了外周或中央色机制的适应性调整，以补偿衰老中的灵敏度损失。我们问是否类似的补偿性调整在维持空间视觉中发挥作用，以及适应本身是否显示出随着年龄的变化，通过检查适应对图像焦点判断的影响。适应制服后的感知后遗症。在年轻人和老年观察者之间比较了视野和模糊或锐化的图像。受试者适应一系列模糊或锐化的图像120秒，并使用两种选择的强制选择楼梯任务来改变。测试的滤波器指数，以定义最佳聚焦的主观点。有一个小的，但显着的差异，年轻和年长的观察员在所有三个适应条件下，最好的集中水平，可能反映了环境模糊水平的差异，这些群体经常接触。然而，两个年龄组之间的模糊后效应的大小没有差异。这些结果表明，虽然可能有小的差异，在长期的适应模糊，年轻和老年观察员没有不同的适应模糊的瞬态变化的强度。因此，调节模糊适应的神经过程似乎在很大程度上保持不变。
Color appearance remains remarkably stable in the aging visual system despite large changes in the spectral distribution of the retinal stimulus and losses in chromatic sensitivity (P. B. Delahunt, J. L. Hardy, K. Okajima, & J. S. Werner, 2005; J. S. Werner, 1996). This stability could reflect adaptive adjustments in peripheral or central chromatic mechanisms that compensate for sensitivity losses in senescence. We asked whether similar compensatory adjustments play a role in maintaining spatial vision-and whether the adaptation itself shows changes with aging-by examining the effects of adaptation on judgments of image focus. Perceptual aftereffects following adaptation to a uniform. field and blurred or sharpened images were compared between younger adults and older observers. Subjects adapted to a sequence of blurred or sharpened images for 120 s, and a two-alternative forced-choice staircase task was used to vary the. filter exponent of the test to define the subjective point of best focus. There was a small but significant difference between younger and older observers in the level perceived as best focused in all three adaptation conditions, possibly reflecting differences in the ambient blur level the groups are routinely exposed to. However, the magnitude of the blur after effect did not differ between the two age groups. These results suggest that although there may be small differences in the long-term adaptation to blur, younger and older observers do not differ in the strength of adaptation to transient changes in blur. The neural processes mediating adaptation to blur thus appear to remain largely intact with aging.