Neural Basis of Categories

描述：(由申请人提供)虽然对分析视觉环境的物理属性的神经机制了解很多， 人们对这些分析的结果知之甚少：分配 赋予刺激意义的类别。我们小组开发了一种新的范例 用于研究视觉类别。变形系统用于混合原型 猫和狗组成的单个图像，每个图像都有一定的 猫和狗的比例。这使得我们可以不断地改变形状和 准确定义类别边界。猴子被训练来判断两个 相继呈现的图像来自同一类别。我们最近发现了一个 前额叶皮质(PFC)类别信息的神经关联：单一 在交界处显示神经活动急剧变化的神经元 类别，但类别内的活动差异相对较小。 我们现在计划使用这个范例来解决基本问题 关于类别表示法。使用多个电极 技术，我们将同时记录来自PFC和 下颞叶皮质(TIC)，一个被认为是重要的视觉皮质区域 用于视觉类别。这将使我们能够直接比较和对比 它们的神经特性和相对时序，因此提供了精确的 评估各自对基于类别的行为的贡献。我们会 还要测试海马体中的类别编码，海马体是一个共享密切联系的区域 与TIC和PFC的解剖和功能关系。来探索是否 分类和识别有共同的神经基础，我们会记录下来 当猴子在分类之间来回切换时，PFC和ITC活动 刺激和识别个别类别成员。要确定是否 分类编码神经元是高度专门化的(就像“脸部细胞”)，我们将 用各种现实世界的刺激来测试它们。以确定是否 多个类别成员关系由单独的神经集成或 取而代之的是多路传输到单个神经元上，我们将在猴子切换时进行记录 在将一组刺激归类到两个不同的类别方案下之间。 因为分类是认知的核心，这个项目的数据具有 有可能对广泛的行为和人类疾病产生影响。这个 从经验中快速收集概念和意义的能力在 各种神经精神障碍，如自闭症和精神分裂症。通过 识别对这些能力重要的大脑结构，辨别它们的 相关角色，并揭示它们的神经机制，我们可以开辟一条道路 旨在缓解他们功能障碍的药物和行为疗法。

DESCRIPTION: (provided by applicant) While much is understood about neural mechanisms that analyze the physical attributes of the visual environment, little is known about the culmination of these analyses: the assignment of categories that give stimuli meaning. Our group has developed a novel paradigm for studying visual categories. A morphing system is used to blend prototypes of "cats" and "dogs" into single images, with each image having a certain proportion of cat vs. dog. This allows us to continuously vary shape and precisely define a category boundary. Monkeys are trained to judge whether two successively presented images are from the same category. We recently found a neural correlate of category information in the prefrontal cortex (PFC): single neurons that show a sharp change in neural activity at the boundary between categories but relatively little differences in activity within a category. We now plan to use this paradigm to address fundamental questions about category representations. Using multiple electrode techniques, we will simultaneously record neural activity from the PFC and the inferior temporal cortex (TIC), a visual cortical area thought to be important for visual categories. This will allow us to directly compare and contrast their neural properties and relative timing and thus afford a precise assessment of the respective contributions to category-based behaviors. We will also test for category-coding in the hippocampus, a region that shares a close anatomical and functional relationship with the TIC and PFC. To explore whether categorization and identification have common neural substrates, we will record PFC and ITC activity while monkeys switch back and forth between categorizing stimuli and identifying individual category members. To determine if category-coding neurons are highly specialized (like "face cells"), we will test them with a wide range of real world stimuli. To determine whether multiple category memberships are represented by separate neural ensembles or instead multiplexed onto single neurons, we will record while monkeys switch between categorizing a set of stimuli under two different category schemes. Because categorization is central to cognition, data from this project has the potential to impact on a wide range of behaviors and human disorders. The ability to quickly glean concepts and meaning from experience is disrupted in a variety of neuro psychiatric disorders such as autism and schizophrenia. By identifying brain structures important for these abilities, discerning their relative roles, and uncovering their neural mechanisms, we can open a path to drug and behavioral therapies designed to alleviate their dysfunction.