FMRI INVESTIGATIONS OF THE PARAHIPPOCAMPAL PLACE AREA

所有的导航生物都必须回答一个基本的问题， 是吗我实验室过去8个月的功能磁共振成像研究 在大脑皮层中发现了一个区域我们称之为海马旁区 (PPA)，这似乎在解决这个问题方面发挥了核心作用。 我们已经在30名受试者中的28名中对PPA进行了功能定位 测试并表明PPA以高度选择性的方式响应， 时尚的视觉刺激描绘的地方，反应强烈时， 受试者观看室内和室外场景的照片， 对常见物体和面孔的照片的反应很弱。 的目标 拟议的研究是详细说明PPA的确切功能 相关的神经结构（例如，海马体、嗅周和 内嗅皮层和顶叶区域）的位置感知， 导航和空间认知。 第一部分的实验奠定了 为今后的研究奠定基础， PPA的功能特性和相关结构的详细信息。 第二部分中的实验旨在精确表征 驱动PPA的各种刺激。在明确定义了 激活PPA的刺激类别，第三部分将确定 处理PPA和相关神经结构的性质 在这些刺激下进行。 具体来说，这些实验测试了 PPA和其他区域参与I）感知 刺激的分析（知觉假说），ii） 将该感知信息与存储的 地方的出现（承认假说），iii） 将知觉信息编码到记忆中（记忆 编码假设），和/或iv）确定如何从 当前位置到认知地图中的某个其他已知位置， 即路线规划假设（Route-Planning Hypothesis）

All navigating organisms must answer the fundamental question, where am I now? FMRI research in my lab over the last 8 months has identified a region of cortex we call the parahippocampal place area (PPA), which appears to play a central role in solving that problem. We have functionally localized the PPA in 28 out of 30 subjects tested and have shown that the PPA responds in a highly selective fashion to visual stimuli depicting places, responding robustly when subjects view photographs of indoor and outdoor scenes, yet only very weakly to photographs of common objects and faces. The goal of the proposed research is to specify the precise function of the PPA associated neural structures (e.g., the hippocampus, perirhinal and entohinal cortex, and parietal regions) in place perception, navigation, and spatial cognition. The experiments in Part I lay the groundwork for future studies by characterizing the anatomical and functional properties of the PPA and associated structures in detail. The experiments in Part II are designed to precisely characterize the kinds of stimuli that drive the PPA. Having clearly defined the categories of stimuli that activate the PPA, Part III will determine the nature of the processing the PPA and associated neural structures carry out on those stimuli. Specifically, these experiments test the involvement of the PPA and other regions in I) the perceptual analysis of the stimulus (the Perception Hypothesis), ii) the comparing of that perceptual information to stored representations of the appearances of places (the Recognition Hypothesis), iii) the encoding of theat perceptual information into memory (the Memory Encoding Hypothesis), and/or iv) determining how to get from the current location to some other known location in the cognitive map, i.e. route planning (the Route-Planning Hypothesis)