Measures of Subjective Variables in Visual Cognition

当人们被要求做一些与视觉有关的认知任务时，比如想象一个物体或在一个大的视觉阵列中搜索一个特定的物体，众所周知，显示器的某些物理上可测量的“客观”方面，例如它的复杂性，会影响人们完成任务的方式。此外，主观方面也会影响人们的表现，这些方面是无法用肉体测量的，比如熟悉度或意义。很少有实验将客观变量与主观变量充分分离，以至于人们可以断定哪些实验效果不够具体。本研究项目的实验将把主观变量从客观变量中分离出来，并将考察主观变量在一系列基于视觉的认知任务中的作用，包括表象任务、搜索任务和知觉反转任务。这些任务都潜在地受到观察者关于要想象或操纵的形状的结构的知识的影响。这项研究源于这样一个概念，即视觉认知中的主观效果是由观看者关于构成形状的特定组件以及这些组件的相对位置的结构知识所中介的；结构知识越多，图像可以被操作、搜索和扫描得越快，因此观看者的表现就越高效。实验将检验这一概念，并在此过程中，试图将结构性知识的结构与整体加工的结构分开，并考察空间注意与结构性知识之间的相互作用。最后，这项研究将开发任务的功能分类，以确定产生主观效果的加工类型。假说是，当任务允许对可分类的基本形状进行心理操作时，这些效应就会发生，而不是要求对详细的特定形状进行操作。这种任务分类，连同结构知识的结构，可能有助于识别在要求速度和准确性的真实世界任务中使用的视觉认知的“功能词汇”。

When people are asked to do a number of cognitive tasks involving vision, such as imaging an object or searching for a particular object in a large visual array, it is well known that certain physically measurable, "objective" aspects of the display, such as its complexity, influence how people do the tasks. In addition, subjective aspects, ones that cannot be measured physically, such as familiarity or meaning, also influence people's performance. Few experiments have separated objective from subjective variables sufficiently that one can tell conclusively which ones underly particular experimental effects. The experiments in this research project will isolate subjective variables from objective variables and will examine the role of subjective variables in a series of visually-based cognitive tasks, including imagery tasks, search tasks, and perceptual reversal tasks. These tasks are all potentially influenced by the viewer's knowledge regarding the structure of the shape to be imagined or manipulated. The research flows from the notion that subjective effects in visual cognition are mediated by the viewer's structural knowledge regarding the particular components from which a shape is constructed and the relative locations of these components; the greater the structural knowledge, the faster images can be manipulated, searched, and scanned, and hence, the more efficient the viewer's performance. The experiments will test this notion and, in the process, will attempt to separate the construct of structural knowledge from that of wholistic processing and to examine the interaction between spatial attention and structural knowledge. Finally, the research will develop a functional taxonomy of tasks to identify the types of processing that yield subjective effects. The hypothesis is that these effects will occur when tasks permit the mental manipulation of categorizable, basic- level shapes rather than requiring manipulation of detailed particular shapes. This taxonomy of tasks, together with the construct of structural knowledge, may be useful in identifying the "functional vocabulary" of visual cognition that is employed in real-world tasks requiring speed and accuracy.