Cortical Mechanisms of Visual Category Recognition and Learning

拟议研究的摘要和相关性 人类和其他高级动物有令人印象深刻的能力来认识到行为的重要性，或者 类别成员，范围广泛的感觉刺激。这种能力被许多大脑所破坏 阿尔茨海默氏症、精神分裂症、中风和注意力缺陷障碍等疾病和状况 至关重要，因为它允许我们对连续的刺激和事件做出适当的反应 在我们与环境的互动中相遇。当然，我们与生俱来就没有一个内置的图书馆 有意义的类别，如“桌子”和“椅子”，我们被预先编程来识别。相反，我们 学会通过体验来认识这类刺激的意义。这里提出的研究的目标是 对学习和识别背后的大脑机制有更详细的了解 视觉类别。最近的研究表明，后顶叶皮质和前额叶皮质都是 参与对视觉刺激的类别成员进行编码并形成分类决策。在这些 研究中，我们记录了在执行分类任务期间顶叶皮质的神经元 360度的运动方向被分成两个任意的类别，这两个类别被学习的类别划分 边界。这些记录显示，这两个区域的神经元根据它们的 学习类别成员关系，表明顶层视觉表征可以反映抽象信息 关于视觉刺激的习得意义。拟议研究的目标是开发一种机械式的 理解视觉皮层中的视觉特征表征如何快速转化为类别 在顶叶和前额叶皮质进行编码，以了解灵活的基于规则的决策的机制 制作，并确定神经元类别表征在类别期间如何实时发展 学习过程。 虽然对大脑如何处理简单的感觉功能(如颜色、方向和 运动方向)，对大脑如何学习和表示意义或类别知之甚少 刺激物。更好地理解视觉学习和分类对于解决一些 大脑疾病和状况(例如中风、阿尔茨海默病、注意力缺陷障碍、精神分裂症和 中风)，使患者在需要视觉学习、识别和/或评估的日常任务中受损 以及对感官信息做出适当的反应。这个项目的长期目标是指导下一步 这些基于大脑的疾病和障碍的治疗方法的产生，通过帮助制定详细的 了解构成学习、记忆和识别的大脑机制。这些研究还包括 与理解和解决学习障碍相关，如注意力缺陷障碍和 阅读障碍，这影响了相当一部分学龄儿童和年轻人。因此，一个更详细的 对学习和注意力背后的基本大脑机制的理解可能会对 对涉及这些认知能力的障碍的原因和可能的治疗方法的见解。

Summary and Relevance of Proposed Research Humans and other advanced animals have an impressive capacity to recognize the behavioral significance, or category membership, of a wide range of sensory stimuli. This ability, which is disrupted by a number of brain diseases and conditions such as Alzheimer's disease, schizophrenia, stroke, and attention deficit disorder, is critical because it allows us to respond appropriately to the continuous stream of stimuli and events that we encounter in our interactions with the environment. Of course, we are not born with a built in library of meaningful categories, such as “tables” and “chairs”, which we are preprogrammed to recognize. Instead, we learn to recognize the meaning of such stimuli through experience. The goal of the studies proposed here is to move towards a more detailed understanding of the brain mechanisms underlying the learning and recognition visual categories. Recent work has shown that both the posterior parietal cortex and prefrontal cortex are involved in encoding the category membership of visual stimuli and forming categorical decisions. In these studies, we recorded from neurons in the parietal cortex during performance of a categorization task in which 360º of motion directions were grouped into two arbitrary categories that were divided by a learned category boundary. These recordings revealed that neurons in both areas robustly encoded stimuli according to their learned category membership, suggesting that parietal visual representations can reflect abstract information about the learned significance of visual stimuli. The goals of the proposed studies are to develop a mechanistic understanding of how visual feature representations in visual cortex are rapidly transformed into category encoding in parietal and prefrontal cortices, to understand the mechanisms of flexible rule-based decision making, and to determine how neuronal category representations develop in real time during the category learning process. While much is known about how the brain processes simple sensory features (such as color, orientation, and direction of motion), less is known about how the brain learns and represents the meaning, or category, of stimuli. A greater understanding of visual learning and categorization is critical for addressing a number of brain diseases and conditions (e.g. stroke, Alzheimer's disease, attention deficit disorder, schizophrenia, and stroke) that leave patients impaired in everyday tasks that require visual learning, recognition and/or evaluating and responding appropriately to sensory information. The long-term goal of this project is to guide the next generation of treatments for these brain-based diseases and disorders by helping to develop a detailed understanding of the brain mechanisms that underlie learning, memory and recognition. These studies also have relevance for understanding and addressing learning disabilities, such as attention deficit disorder and dyslexia, which affect a substantial fraction of school age children and young adults. Thus, a more detailed understanding of the basic brain mechanisms underlying learning and attention will likely give important insights into the causes and potential treatments for disorders involving these cognitive faculties.