Retter Talia L, Rossion Bruno
Perception. 2015;44(5):511-28. doi: 10.1068/p7826.
The separation of visual shape and surface information may be useful for understanding holistic face perception--that is, the perception of a face as a single unit (Jiang, Blanz, & Rossion, 2011, Visual Cognition, 19, 1003-1034). A widely used measure of holistic face perception is the composite face effect (CFE), in which identical top face halves appear different when aligned with bottom face halves from different identities. In the present study the influences of global face shape (ie contour of the face) and color information on the CFE are investigated, with the hypothesis that global face shape supports but color impairs holistic face perception as measured in this paradigm. In experiment 1 the CFE is significantly increased when face stimuli possess natural global shape information than when cropped to a generic (ie oval) global shape; this effect is not found when the stimuli are presented inverted. In experiment 2 the CFE is significantly decreased when face stimuli are presented with color information than when presented in grayscale. These findings indicate that grayscale stimuli maintaining natural global face shape information provide the most adept measure of holistic face perception in the behavioral composite face paradigm. More generally, they show that reducing different types of information diagnostic for individual face perception can have opposite effects on the CFE, illustrating the functional dissociation between shape and surface information in face perception.
视觉形状与表面信息的分离可能有助于理解整体面部感知——也就是说，将面部视为一个单一单元的感知（Jiang、Blanz和Rossion，2011年，《视觉认知》，第19卷，第1003 - 1034页）。一种广泛使用的整体面部感知测量方法是合成脸效应（CFE），在这种效应中，当相同的上半脸与来自不同身份的下半脸对齐时，会显得不同。在本研究中，研究了整体面部形状（即面部轮廓）和颜色信息对CFE的影响，假设是整体面部形状支持但颜色会损害在该范式中测量的整体面部感知。在实验1中，当面部刺激具有自然的整体形状信息时，CFE比裁剪为通用（即椭圆形）整体形状时显著增加；当刺激以倒置形式呈现时未发现这种效应。在实验2中，当面部刺激呈现颜色信息时，CFE比以灰度呈现时显著降低。这些发现表明，保持自然整体面部形状信息的灰度刺激在行为合成脸范式中提供了最能体现整体面部感知的测量方法。更一般地说，它们表明减少用于个体面部感知的不同类型信息诊断对CFE可能有相反的影响，说明了面部感知中形状和表面信息之间的功能分离。
