The M170 reflects a viewpoint-dependent representation for both familiar and unfamiliar faces
The M170 reflects a viewpoint-dependent representation for both familiar and unfamiliar faces
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DOI：
10.1093/cercor/bhm060
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发表时间：
2008-02-01
期刊：
影响因子：
3.7
通讯作者：
Andrews, Timothy J.
中科院分区：
文献类型：
--
作者：
Ewbank, Michael P.;Smith, William A. P.;Andrews, Timothy J.
本研究的目的是确定在何种程度上的神经表征的面孔在视觉皮层是观点依赖或观点不变。脑磁图被用来测量诱发反应的面孔在适应范式。使用熟悉和不熟悉的面孔，我们比较了M170反应的幅度重复图像相同的脸与图像的不同的脸。我们发现，从相同的角度来看，与不同面孔的图像相比，重复呈现相同的人脸图像时，M170振幅会降低。为了确定这种对人脸身份的适应是否对视点的变化是不变的，我们在一个块内改变了人脸的视角。我们发现，当同一张脸的图像从不同的角度显示时，反应的减少不再明显。这种观点依赖的结果模式对熟悉和不熟悉的面孔都是一样的。这些结果意味着，无论是面部选择性M170反应反映了面部处理的早期阶段，或面部识别的计算基础上依赖于一个视点依赖的神经元表示。
The aim of this study was to determine the extent to which the neural representation of faces in visual cortex is viewpoint dependent or viewpoint invariant. Magnetoencephalography was used to measure evoked responses to faces during an adaptation paradigm. Using familiar and unfamiliar faces, we compared the amplitude of the M170 response to repeated images of the same face with images of different faces. We found a reduction in the M170 amplitude to repeated presentations of the same face image compared with images of different faces when shown from the same viewpoint. To establish if this adaptation to the identity of a face was invariant to changes in viewpoint, we varied the viewing angle of the face within a block. We found a reduction in response was no longer evident when images of the same face were shown from different viewpoints. This viewpoint-dependent pattern of results was the same for both familiar and unfamiliar faces. These results imply that either the face-selective M170 response reflects an early stage of face processing or that the computations underlying face recognition depend on a viewpoint-dependent neuronal representation.