Dissecting the neural circuits for face perception in macaque inferotemporal cort

描述(申请人提供)：这项计划的目标是了解猕猴大脑中调节脸部知觉的神经回路。面孔是灵长类动物大脑处理的最有意义的视觉形式之一，传达关于身份、表情、性别、年龄和注意力方向的信息。功能磁共振成像(FMRI)揭示了猕猴颞叶面部处理的专门化：大脑皮质的六个离散区域对人脸图像的反应比对其他物体的图像更强烈。脸部这些区域的专门化程度令人惊叹：当以单一单元记录为目标时，到目前为止广泛测试的所有四个区域都几乎完全由脸部选择细胞组成。这些区域被称为“脸部斑块”，位于两个半球的相似位置，并横跨个体。FMRI和微刺激相结合的实验表明，人脸斑块是强烈和特定的相互联系，而电生理实验表明，不同的斑块在功能上是不同的。人脸贴片系统提供了一个独特的机会来剖析形状感知的神经机制，因为该系统专门处理一类复杂的形状，而且它的计算组件在空间上是分离的。我们认为，理解面部贴片系统的中心实验挑战是理解每个贴片的功能专门化以及这种专门化是如何产生的。为了应对这一挑战，我们计划从四个方面来询问系统：1)表征：每个面片中的细胞的选择性和不变性是什么？2)行为角色：停用特定的面片对各种与人脸相关的行为有什么影响？3)连通性：面片的接线图是什么？以及4)转换：每个面片中输入和输出细胞之间的关键功能差异是什么？解决这些问题将阐明面部贴片系统内信息流的原理，并阐明颞下皮质的一般组织原理。

Description (provided by applicant): The goal of this proposal is to understand the neural circuits of the macaque brain mediating face perception. Faces are among the most meaningful visual forms processed by the primate brain, conveying information about identity, expression, gender, age, and direction of attention. Functional magnetic resonance imaging (fMRI) reveals a specialization for face processing in the macaque temporal lobe: six discrete regions of cortex respond much more strongly to images of faces than to images of other objects. The degree of specialization of these regions for faces is breathtaking: when targeted for single-unit recording, all four regions tested extensively so far turned out to consist almost entirely of face-selective cells. These regions, termed "face patches", are located at similar positions in the two hemispheres and across individuals. Experiments combining fMRI with microstimulation demonstrate that the face patches are strongly and specifically interconnected, yet electrophysiological experiments show that different patches are functionally distinct. The face patch system offers a unique opportunity to dissect the neural mechanisms underlying form perception, because the system is specialized to process one class of complex forms, and because its computational components are spatially segregated. We believe the central experimental challenge to understanding the face patch system is to understand the functional specialization of each patch and how this specialization comes about. To address this challenge, we plan to interrogate the system from four directions: 1) Representations: What are the selectivity and invariance properties of cells in each face patch?, 2) Behavioral Role: What is the effect of inactivating specific face patches on various face-related behaviors?, 3) Connectivity: What is the wiring diagram of the face patches?, and 4) Transformations: What are the key functional differences between input and output cells within each face patch? Addressing these questions will elucidate the principles of information flow within the face patch system and shed light on the general organizing principles of inferotemporal cortex.