Neural Basis of Categories

描述：（由申请人提供）虽然对神经系统有很多了解， 分析视觉环境的物理属性的机制， 关于这些分析的最终结果知之甚少： 赋予刺激意义的类别。我们的团队开发了一种新的模式 来研究视觉分类。变形系统用于混合原型 将“猫”和“狗”分成单个图像，每个图像具有一定的 猫与狗的比例这使我们能够不断改变形状， 准确定义类别边界。猴子被训练来判断两个 连续呈现的图像来自同一类别。我们最近发现了一个 前额叶皮层（PFC）中类别信息的神经相关：单个 神经元在神经活动中显示出急剧的变化， 类别，但在一个类别内的活动差异相对较小。 我们现在计划用这个范例来解决一些基本问题 关于类别表示的。使用多个电极 技术，我们将同时记录PFC和 下颞叶皮层（TIC），一个被认为是重要的视觉皮层区域， 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间，从而提供了一个精确的 评估各自对基于类别的行为的贡献。我们将 我们还测试了海马体中的分类编码，海马体是一个与人类有着密切联系的区域。 与TIC和PFC的解剖和功能关系。 分类和识别有共同的神经基质，我们将记录 PFC和ITC活动，而猴子在分类之间来回切换 刺激和识别个体类别成员。以确定是否 类别编码神经元是高度专业化的（如“脸细胞”），我们将 用广泛的真实的世界刺激来测试它们。以确定是否 多个类别成员由单独的神经集合表示，或者 我们将记录猴子切换的同时， 在两种不同的分类方案下对一组刺激进行分类。 由于分类是认知的核心，因此来自该项目的数据具有 可能对广泛的行为和人类疾病产生影响。的 从经验中快速收集概念和意义的能力被破坏， 各种神经精神疾病，如自闭症和精神分裂症。通过 识别对这些能力很重要的大脑结构，辨别它们的 相对角色，并揭示其神经机制，我们可以打开一条道路， 药物和行为疗法旨在减轻他们的功能障碍。

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.