Rao Rajesh P N, Zelinsky Gregory J, Hayhoe Mary M, Ballard Dana H
Department of Computer Science, University of Rochester, Rochester, NY 14627, USA.
Vision Res. 2002 May;42(11):1447-63. doi: 10.1016/s0042-6989(02)00040-8.
Visual cognition depends critically on the moment-to-moment orientation of gaze. To change the gaze to a new location in space, that location must be computed and used by the oculomotor system. One of the most common sources of information for this computation is the visual appearance of an object. A crucial question is: How is the appearance information contained in the photometric array is converted into a target position? This paper proposes a such a model that accomplishes this calculation. The model uses iconic scene representations derived from oriented spatiochromatic filters at multiple scales. Visual search for a target object proceeds in a coarse-to-fine fashion with the target's largest scale filter responses being compared first. Task-relevant target locations are represented as saliency maps which are used to program eye movements. A central feature of the model is that it separates the targeting process, which changes gaze, from the decision process, which extracts information at or near the new gaze point to guide behavior. The model provides a detailed explanation for center-of-gravity saccades that have been observed in many previous experiments. In addition, the model's targeting performance has been compared with the eye movements of human subjects under identical conditions in natural visual search tasks. The results show good agreement both quantitatively (the search paths are strikingly similar) and qualitatively (the fixations of false targets are comparable).
视觉认知严重依赖于注视的瞬间方向。为了将目光转移到空间中的新位置，该位置必须由眼动系统进行计算并加以利用。这种计算最常见的信息来源之一是物体的视觉外观。一个关键问题是：光度阵列中包含的外观信息是如何转换为目标位置的？本文提出了一个完成此计算的模型。该模型使用从多个尺度的定向时空色度滤波器导出的图像场景表示。对目标物体的视觉搜索以从粗到细的方式进行，首先比较目标的最大尺度滤波器响应。与任务相关的目标位置表示为显著性图，用于规划眼动。该模型的一个核心特征是，它将改变注视的目标过程与在新注视点或其附近提取信息以指导行为的决策过程分开。该模型为许多先前实验中观察到的重心扫视提供了详细解释。此外，在自然视觉搜索任务的相同条件下，将该模型的目标性能与人类受试者的眼动进行了比较。结果在定量（搜索路径惊人地相似）和定性（错误目标的注视情况相当）两方面都显示出良好的一致性。
