Wright Alissa, Barton Jason J S
Faculty of Medicine, University of Toronto, Toronto, Canada.
Vision Res. 2008 Nov;48(25):2545-54. doi: 10.1016/j.visres.2008.08.019. Epub 2008 Oct 4.
Current models of face processing support an orientation-dependent expert face processing mechanism. However, even when upright, faces are encountered from different viewpoints, across which a face processing system must be able to generalize. Different computational models have generated competing predictions of how viewpoint variation might affect the perception of upright versus inverted faces. Our goal was to examine the interaction between viewpoint variation and orientation on face discrimination. Sixteen normal subjects performed an oddity paradigm requiring subjects to discriminate changes in three simultaneously viewed morphed faces presented either upright or inverted. In one type of trial all the faces were seen in frontal view; in the other all faces varied in viewpoint, rotated 45 degrees from each other. After the effects of orientation were adjusted for perceptual difficulty, there were only main effects of orientation and viewpoint, with no interaction between orientation and viewpoint. We conclude that the effects of viewpoint variation on the perceptual discrimination of faces is not different for upright versus inverted faces, indicating that its effects are independent of the expertise that exists for upright faces.
当前的面部处理模型支持一种依赖于朝向的专家级面部处理机制。然而，即使面部是正立的，人们也会从不同视角遇到它们，而面部处理系统必须能够在这些视角之间进行泛化。不同的计算模型对视角变化可能如何影响正立与倒立面部的感知产生了相互竞争的预测。我们的目标是研究视角变化和朝向对面部辨别能力的相互作用。16名正常受试者进行了一个奇异范式实验，要求受试者辨别同时呈现的三张正立或倒立的变形面部的变化。在一种试验类型中，所有面部都以正视图呈现；在另一种试验类型中，所有面部的视角都不同，彼此之间旋转了45度。在针对感知难度调整了朝向的影响后，仅存在朝向和视角的主效应，朝向和视角之间没有交互作用。我们得出结论，视角变化对正立和倒立面部感知辨别的影响并无差异，这表明其影响独立于正立面部所存在的专门处理机制。
