Cortical Areas and Neural Connections Underlying Scene Processing

描述（由申请人提供）：在人类受试者中，神经影像学和其他技术已经揭示了视觉皮层的不同区域对不同类型的视觉刺激有特异性反应。例如，人脸会选择性地激活大脑的一组特定区域，而场景会激活另一组区域，包括“PPA”、“TOS”和“RSC”区域。了解对环境中场景作出反应的区域的功能和联系，将为了解正常受试者导航和感知视觉场景所使用的总体策略提供基本的见解。此外，这些皮质中心的脑损伤与许多神经系统综合征有关，包括面孔失认症、导航失认症和威廉姆斯综合征。由于研究人类受试者的技术无法揭示该网络功能背后的所有基本神经机制，动物模型为理解环境感知的神经基础提供了重要手段。本建议的目标之一就是提供这样一个模型。我们的第一个目标（目标#1）是通过在非人类灵长类动物中使用功能性磁成像（fMRI）来证明三个场景响应区域的存在，然后定量地比较皮层图，以表明人类和猴子的场景响应区域是一致的。根据我们的初步数据，我们预计这一目标将成功完成。这将允许使用经典的微创技术（例如神经示踪剂）来阐明场景处理的特定电路（目标2）。三种基于核磁共振成像的技术（包括新方法）将用于追踪灵长类动物这三个区域之间的神经连接。多种追踪技术的使用将提供关于皮质连接的综合信息，并在一个共同的系统中验证每种技术。目标#2还将回答有关神经场景处理背后的神经连接的具体问题：这三个区域是否相互连接，和/或与背侧（“什么”）流连接，和/或与海马体多突触连接，在海马体中，“位置编码”神经元是众所周知的？在Aim #3中，我们将使用fMRI将感觉驱动的信息（在Aims #1/2中）跟踪到灵长类动物皮层中更高的大脑水平，这是在场景识别任务期间驱动的。在人类中，相同的识别任务在皮层斑块中产生了与面部识别任务不同的强劲活动。我们的假设是，当猴子执行相同的识别任务时，fMRI活动将在相应的皮层区域产生。成功完成所有目标将使用不同的基于mri的方法来展示警觉灵长类动物的场景处理网络，范围从感觉驱动到任务驱动，以及这些区域之间的联系。

DESCRIPTION (provided by applicant): In human subjects, neuroimaging and other techniques have revealed that different regions of visual cortex respond specifically to distinct types of visual stimuli. For instance, faces selectively activate one specific set of brain regions, and scenes activate a different set, including the areas named 'PPA,' 'TOS' and 'RSC'. Understanding the function and connections of the regions that respond to scenes in the environment will provide fundamental insights about the overall strategies used by normal subjects to navigate and to perceive visual scenes. Moreover, brain damage to each of these cortical centers has been implicated in numerous neurological syndromes, including prosopagnosia, navigation agnosia and Williams Syndrome. Because the techniques available to study human subjects cannot reveal all of the basic neural mechanisms underlying the function of this network, animal models provide an essential means to understand the neural basis of the environmental perception. One goal of this proposal is to provide such a model. Our first goal (Aim #1) is to demonstrate the existence of three scene-responsive areas by using functional magnetic imaging (fMRI) in non-human primates, then to compare the cortical maps quantitatively, to show that the scene-responsive regions correspond across humans and monkeys. Based on our preliminary data, we anticipate successful completion of this aim. This will enable the use of classical, minimally invasive techniques (e.g. neural tracers) to clarify the specific circuits of scene processing (Aim #2). Three MRI-based techniques (including novel methods) will be used to trace the neural connections between each of these three areas in primates. The use of multiple tracing techniques will furnish integrated information about the cortical connections, and validate each of the techniques in a common system. Aim #2 will also answer specific questions about the neural connections underlying neural scene processing: do these three areas connect with each other, and/or with the dorsal (the 'what') stream, and/or multi-synaptically to the hippocampus, in which 'place-coding' neurons are well-known? In Aim #3, we will use fMRI to track sensory-driven information (in Aims #1/2) to higher brain levels in primate cortex, which are driven during scene recognition tasks. In humans, an identical recognition task produced robust activity in the cortical patches distinct from those produced in a face recognition task. Our hypothesis is that fMRI activity will be produced in homologous cortical areas, when monkeys are performing an equivalent recognition task. Successful completion of all aims will use different MRI-based methods to demonstrate a scene- processing network in alert primates, ranging from sensory-driven to task-driven, and the connections between these areas.