Peterson Mary A, Salvagio Elizabeth
Department of Psychology, University of Arizona, Tucson, AZ 85721, USA.
J Vis. 2008 Dec 15;8(16):4.1-13. doi: 10.1167/8.16.4.
Convexity has long been considered a potent cue as to which of two regions on opposite sides of an edge is the shaped figure. Experiment 1 shows that for a single edge, there is only a weak bias toward seeing the figure on the convex side. Experiments 1-3 show that the bias toward seeing the convex side as figure increases as the number of edges delimiting alternating convex and concave regions increases, provided that the concave regions are homogeneous in color. The results of Experiments 2 and 3 rule out a probability summation explanation for these context effects. Taken together, the results of Experiments 1-3 show that the homogeneity versus heterogeneity of the convex regions is irrelevant. Experiment 4 shows that homogeneity of alternating regions is not sufficient for context effects; a cue that favors the perception of the intervening regions as figures is necessary. Thus homogeneity alone does not alone operate as a background cue. We interpret our results within a model of figure-ground perception in which shape properties on opposite sides of an edge compete for representation and the competitive strength of weak competitors is further reduced when they are homogeneous.
长期以来，凸性一直被视为一种有力线索，用以判断边缘两侧的两个区域中哪个是有形状的图形。实验1表明，对于单一边缘，人们仅有微弱的偏向，倾向于将图形视为位于凸面一侧。实验1至3表明，只要界定交替凸凹区域的边缘数量增加，且凹面区域颜色均匀，那么将凸面一侧视为图形的偏向就会增加。实验2和3的结果排除了对这些背景效应的概率总和解释。综合来看，实验1至3的结果表明，凸面区域的同质性与异质性无关。实验4表明，交替区域的同质性不足以产生背景效应；需要一个有利于将中间区域感知为图形的线索。因此，仅同质性本身并不能作为背景线索发挥作用。我们在一个图形-背景感知模型中解释我们的结果，在该模型中，边缘两侧的形状属性竞争表征，当弱竞争者属性相同时，其竞争强度会进一步降低。
