Shape Recognition and Figure-Ground Organization

从理论上理解视觉感知的尝试通常将感知过程划分为可以同时进行的过程和必须连续进行的过程。大多数理论家认为图形-背景组织和形状识别是相继进行的。图形-背景组织是确定视野中的哪些区域表示图形以及哪些区域构成观看图形的背景。图形和背景区域由轮廓隔开；轮廓被分配到的区域看起来是可识别的图形，而另一个区域看起来是一个没有区别的背景，只是看起来在图形后面继续。尽管形状识别和图形-背景组织之间存在联系，但这些理论家认为图形-背景组织必须先于形状识别，无论是明确的还是含蓄的，都支持这样一种观点，即一个人只有在有需要识别的图形时才能识别图形。因此，图形-背景关系通常被认为仅由刺激变量确定(即，变量，例如轮廓两侧的两个区域的相对面积、对称性、凸度和包络)。然而，与这一论点相反，彼得森实验室之前的研究表明，某些形状识别分析是在确定图形和背景之前进行的。这些实验可以很容易地整合到当前形状识别的理论方法中，从而使这一论点过时。计划中的实验将检验形状识别过程对图形-背景计算有贡献的条件。一系列实验将识别哪些特定类型的轮廓(例如，亮度轮廓、双目视差轮廓和/或颜色轮廓)允许在分析与图形-背景组织相关的刺激变量的同时执行形状识别计算。另一系列实验将测试与可逆图形-背景刺激的两种解释相对应的形状表征是否在图形-背景轮廓分配之前被同时激活。第三系列实验将试图阐明图形-背景计算中形状识别变量和刺激变量之间相互作用的规则。这些实验将提供有关视觉处理的基本方面的信息，包括分析物理变量与知觉组织中的认知变量相互作用的方式。这些实验肯定会与物理场景的代理设计相关。

Theoretical attempts to understand visual perception often partition perceptual processes into those processes that can be performed simultaneously and those that must be performed successively. Most theorists have assumed that figure-ground organization and shape recognition are performed successively. Figure-ground organization is the determination of which regions in the visual field represent figures and which constitute the backgrounds against which the figures are viewed. Figure and ground regions are separated by a contour; the region to which the contour is assigned appears to be the recognizable figure, whereas the other region appears to be an undifferentiated ground which simply appears to continue behind the figure. Despite the linkage between shape recognition and figure-ground organization, these theorists have argued that figure-ground organization must precede shape recognition, appealing either explicitly or implicitly to the argument that one cannot recognize a figure until there is a figure to be recognized. Consequently, figure-ground relationships are generally conceived to be determined by stimulus variables only (i.e., variables such as the relative areas, symmetries, convexities, and enclosure of the two regions on either side of a contour). Contrary to this argument, however, previous studies in Peterson's laboratory have shown that certain shape recognition analyses are conducted prior to the determination of figure and ground. These experiments can be readily integrated into current theoretical approaches to shape recognition, thereby rendering this argument obsolete. The planned experiments will examine the conditions under which shape recognition processes can contribute to figure-ground computations. One series of experiments will identify which specific types of contours (e.g., luminance contours, binocular disparity contours, and/or color contours) permit shape recognition computations to be performed simultaneously with the analysis of the stimulus variables relevant to figure-ground organization. Another series of experiments will test whether the shape representations corresponding to both interpretations of a reversible figure-ground stimulus are activated simultaneously prior to the assignment of the figure-ground contour. A third series of experiments will attempt to explicate the rules governing the interactions between shape recognition variables and stimulus variables in figure-ground computations. These experiments will provide information about fundamental aspects of visual processing, including the manner in which analyses of physical variables interact with cognitive variables in perceptual organization. These experiments are certain to be relevant to the design of surrogates for physical scenes.