Functional Organization of Visual Object Processing

描述（由申请人提供）：在灵长类视觉系统的高水平（例如那些涉及视觉对象处理的，在“腹侧流”中，包括颞下皮层），我们并不完全了解神经处理。现有的证据主要是基于1)猕猴的单单元记录，或2)人类的功能性磁共振成像（fMRI）。因为这些证据来自不同的技术，在不同的灵长类动物中，有着不同的历史背景，所以很难将这些信息整合到对视觉物体在大脑中如何处理的连贯理解中。这些信息对于最终理解自闭症、面孔失认症和其他失认症以及精神分裂症尤其重要。在这里，我们建议在人类和猕猴中使用功能磁共振成像（fMRI），并在猴子中使用解剖学技术，以缩小这一信息差距，并定义“灵长类”腹侧流的共同功能结构。在许多可能的物体刺激中，我们专注于处理面部的专门神经区域。在目标#1中，我们将使用一种新的功能磁共振成像方法来绘制人类和猴子的面部（和其他物体）产生的活动，以测试如何在皮层地形上绘制特定的刺激变化。目前关于该主题的fMRI信息是基于对多种刺激（对象类别）和/或适应效应的反应，而不是单个刺激产生的直接的、高分辨率的活动图。在目标#2中，我们定量地比较了人类和猴子的面部和物体选择活动的fMRI图，以进一步测试这两个物种中哪些皮质区域“匹配”，哪些不匹配。在测试并确认这些面部和物体选择区域“匹配”之后，我们可以使用经典的神经生物学技术在猕猴身上进一步研究它们（例如目标#3和4），作为人类相应区域的模型。在目标#3中，我们将使用新的基于核磁共振成像的技术来绘制相对于被不同物体激活的附近区域的面部选择皮质区域之间的神经连接。在目标#4中，我们将使用精神物理学来测量猴子的面部感知，并在fmri定义的面部选择区域进行损伤，以测试对面部选择区域的损伤是否可以解释人类患者的面部失认症（面部“失明”）的临床综合征。

DESCRIPTION (provided by applicant): At high levels of the primate visual system (e.g. those involved in visual object processing, in the 'ventral stream' including inferotemporal cortex), we do not fully understand the neural processing. Existing evidence is based largely on 1) single unit recordings from macaque monkey, or from 2) functional magnetic resonance imaging (fMRI) in humans. Because such evidence arises from quite different techniques, in different primates, with different historical backgrounds, it can be difficult to integrate this information into a coherent understanding of how visual objects are processed in brain. Such information is especially important for the eventual understanding of autism, prosopagnosia and other agnosias, and schizophrenia. Here we propose to use functional magnetic resonance imaging (fMRI) in both humans and macaque monkeys, and anatomical techniques in monkeys, to narrow this information gap and to define the common functional architecture of 'primate' ventral stream. Among many possible object stimuli, we focus on specialized neural regions which appear to process faces. In aim #1, we will use a novel fMRI approach to map the activity produced by faces (and other objects), in humans and monkeys, to test how specific stimulus variations are mapped across the cortical topography. Current fMRI information on this topic is instead based on responses to multiple stimuli (object categories) and/or adaptation effects - rather than direct, high-resolution maps of activity produced by individual stimuli. In aim #2, we quantitatively compare the fMRI maps for face- and object-selective activity in humans and monkeys, to further test which of these cortical regions 'match' each other in the two species, and which do not. After testing and confirming that these face- and object-selective regions 'match', we can study them further using classical neurobiological techniques in the macaque (e.g. aims #3 and 4), as a model for corresponding regions in humans. In aim #3, we will use novel MRI-based techniques to map the neural connections to-and-from the face-selective cortical regions, relative to nearby regions which are activated by different objects. In aim #4, we will measure face perception using psychophysics in monkeys, and make lesions in the fMRI-defined face-selective regions, to test whether damage to the face-selective regions may explain the clinical syndrome of prosopagnosia (facial 'blindness') in human patients.