Department of Psychology, University of Pennsylvania.
Department of Psychology, Rutgers University.
J Exp Psychol Hum Percept Perform. 2021 Jan;47(1):134-139. doi: 10.1037/xhp0000874. Epub 2020 Nov 9.
To investigate the role of luminance range for lightness computations in complex 3-dimensional scenes we measured the change in lightness of a surface embedded within a relatively low-luminance-range context, as its perceived spatial position shifted from one plane to another. Our experiment tested conflicting claims between the coplanar ratio principle, according to which large depth effects require a high overall luminance range, and the anchoring theory, which predicts that depth effects can occur with a low overall range, given a sufficiently large difference between the highest luminance values in the 2 planes. Our results show decisive support for the anchoring theory but also hint at a large expansion of the perceived range of reflectances (gray shades) relative to the actual range within each plane. This expansion is qualitatively consistent with anchoring theory's scale normalization principle, but it is surprising in magnitude. Together with our earlier findings showing a massive compression of the perceived reflectance range in unsegmented high-dynamic-range Mondrians, our results underline the urgency of the scaling problem in lightness theory (how luminance range is mapped onto lightness range), a companion of the anchoring problem (which point on the lightness scale is anchored to which point on the luminance scale). (PsycInfo Database Record (c) 2020 APA, all rights reserved).
为了研究亮度范围在复杂三维场景中的明度计算中的作用，我们测量了嵌入在相对低亮度范围内的场景中的表面的明度变化，因为其感知的空间位置从一个平面移动到另一个平面。我们的实验检验了平面比原则和锚固理论之间的冲突，根据平面比原则，大的深度效应需要高的整体亮度范围，而锚固理论则预测，如果两个平面之间的最高亮度值之间存在足够大的差异，则可以在低整体范围下产生深度效应。我们的结果明确支持锚固理论，但也暗示了相对于每个平面内的实际范围，感知的反射率（灰度）范围有很大的扩展。这种扩展与锚固理论的比例归一化原则定性一致，但在数量上令人惊讶。结合我们之前的发现，即在未分段的高动态范围蒙德里安作品中，感知的反射率范围被极大地压缩，我们的结果强调了明度理论中比例问题（亮度范围如何映射到明度范围）的紧迫性，这是锚固问题（明度尺度上的哪个点锚定到亮度尺度上的哪个点）的伴生问题。（PsycInfo 数据库记录（c）2020 APA，保留所有权利）。
