Dissecting the neural circuits for face perception in macaque inferotemporal cort

描述（由申请人提供）：本提案的目标是了解猕猴大脑中调节面部感知的神经回路。脸是灵长类大脑处理的最有意义的视觉形式之一，传递着关于身份、表情、性别、年龄和注意力方向的信息。功能性磁共振成像（fMRI）揭示了猕猴颞叶对人脸处理的专门化：大脑皮层的六个独立区域对人脸图像的反应比对其他物体图像的反应强烈得多。这些面部区域的专门化程度令人惊叹：当以单单元记录为目标时，迄今为止广泛测试的所有四个区域都几乎完全由面部选择细胞组成。这些区域被称为“面部斑块”，位于两个半球和个体之间的相似位置。功能磁共振成像（fMRI）和微刺激相结合的实验表明，面部斑块之间存在强烈的特异性联系，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式感知背后的神经机制，因为该系统专门用于处理一类复杂的形式，而且因为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核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。为了解决这一挑战，我们计划从四个方向对系统进行询问：1)表征：每个面部贴片中细胞的选择性和不变性是什么？2)行为作用：特定面部贴片失活对面部相关行为的影响是什么？3)连通性：面部贴片的接线图是什么？4)转换：每个面部补丁的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，并阐明颞下皮层的一般组织原理。

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.