Norman J Farley, Holmin Jessica S, Beers Amanda M, Cheeseman Jacob R, Ronning Cecilia, Stethen Angela G, Frost Adam L
Department of Psychology & Center for the Study of Lifespan Development, Western Kentucky University, Bowling Green, KY 42101-1030, USA.
Atten Percept Psychophys. 2012 Oct;74(7):1512-21. doi: 10.3758/s13414-012-0340-x.
Two experiments evaluated the ability of younger and older adults to visually discriminate 3-D shape as a function of surface coherence. The coherence was manipulated by embedding the 3-D surfaces in volumetric noise (e.g., for a 55 % coherent surface, 55 % of the stimulus points fell on a 3-D surface, while 45 % of the points occupied random locations within the same volume of space). The 3-D surfaces were defined by static binocular disparity, dynamic binocular disparity, and motion. The results of both experiments demonstrated significant effects of age: Older adults required more coherence (tolerated volumetric noise less) for reliable shape discrimination than did younger adults. Motion-defined and static-binocular-disparity-defined surfaces resulted in similar coherence thresholds. However, performance for dynamic-binocular-disparity-defined surfaces was superior (i.e., the observers' surface coherence thresholds were lowest for these stimuli). The results of both experiments showed that younger and older adults possess considerable tolerance to the disrupting effects of volumetric noise; the observers could reliably discriminate 3-D surface shape even when 45 % of the stimulus points (or more) constituted noise.
两项实验评估了年轻人和老年人根据表面连贯性视觉辨别三维形状的能力。通过将三维表面嵌入体积噪声中来操纵连贯性（例如，对于55%连贯的表面，55%的刺激点落在三维表面上，而45%的点占据相同空间体积内的随机位置）。三维表面由静态双眼视差、动态双眼视差和运动来定义。两项实验的结果都表明了年龄的显著影响：与年轻人相比，老年人需要更高的连贯性（对体积噪声的容忍度更低）才能进行可靠的形状辨别。由运动定义和静态双眼视差定义的表面产生了相似的连贯性阈值。然而，由动态双眼视差定义的表面的表现更优（即，观察者对这些刺激的表面连贯性阈值最低）。两项实验的结果都表明，年轻人和老年人对体积噪声的干扰效应具有相当的耐受性；即使45%（或更多）的刺激点构成噪声，观察者也能可靠地辨别三维表面形状。
