Cortical Mechanisms of Visual Category Recognition and Learning

拟议研究的总结和相关性 人类有一种令人印象深刻的能力来识别感官刺激的类别成员。这种能力， 大脑的活动会被大脑疾病和病症破坏，如阿尔茨海默病，精神分裂症， 中风和注意力缺陷障碍是至关重要的，因为它使我们能够对刺激做出适当的反应， 我们在环境中遇到的事件。我们并不是生来就有一个与生俱来的类别库， 预先设定好的识别程序相反，我们通过经验了解熟悉的类别。我们的工作 结果表明，后顶叶皮层（PPC）和前额叶皮层（PFC）参与了分类 决策我们在视觉运动分类任务中记录了PPC和PFC的神经元，揭示了 这两个区域中的神经元根据它们学习到的类别成员关系对刺激进行鲁棒编码。这说明 这两个区域都涉及表示抽象视觉分类信息。我们还发现， 在PPC的因果关系与分类决策，使用可逆失活。该项目采用新颖的 记录技术，以监测外侧顶内区、额眼 场和上级丘。这将产生一个机械的理解， 这三个区域之间的相互作用使得能够进行作为分类决策基础的计算。这项工作 还将确定多种行为功能是如何由这个大脑网络介导的，包括眼睛。 运动和注意力，以及评估每个大脑区域对分类决策的因果意义。 虽然我们对大脑如何处理视觉特征（如颜色、方向和方向）已经有了很多了解， 运动），较少了解大脑如何学习和代表的意义，或类别，刺激。一 更好地理解视觉分类对于解决一些脑部疾病至关重要， 条件（如中风，阿尔茨海默病，注意力缺陷障碍，精神分裂症和中风），离开 需要视觉学习、识别和/或评估和响应的日常任务受损的患者 与感官信息相匹配该项目的长期目标是指导下一代 通过帮助发展对这些大脑疾病和紊乱的详细了解， 学习记忆和认知的大脑机制这些研究也与 理解和解决学习障碍，如注意力缺陷障碍和诵读困难， 相当一部分学龄儿童和年轻人。因此，详细了解基本的 分类决策和注意力的大脑机制可能会对原因提供重要的见解， 对涉及这些认知和感知能力的疾病的潜在治疗。

Summary and Relevance of Proposed Research Humans have an impressive capacity to recognize the category membership of sensory stimuli. This ability, which is disrupted by a brain-based diseases and conditions such as Alzheimer’s disease, schizophrenia, stroke, and attention deficit disorder, is critical because it allows us to respond appropriately to stimuli and events that we encounter in the environment. We are not born with an innate library of categories which we are preprogrammed to recognize. Instead, we learn about familiar categories through experience. Our work showed that the posterior parietal cortex (PPC) and prefrontal cortex (PFC) are involved in categorical decisions. We recorded from neurons in PPC and PFC during visual motion categorization tasks, revealing that neurons in both areas robustly encode stimuli according to their learned category membership. This shows that both regions are involved in representing abstract visual categorical information. We also showed that activity in PPC is causally related to categorical decisions, using reversible inactivation. This project uses novel recording techniques to monitor activity of large neural populations in the lateral intraparietal area, frontal eye field, and superior colliculus during categorical decisions. This will yield a mechanistic understanding of how interactions between these three regions enable computations which underlie categorical decisions. This work will also determine how multiple behavioral functions are mediated by this brain network, including eye movements and attention, as well assess the causal significance of each brain area to categorical decisions. While much is known about how the brain processes visual 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 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 detailed understanding of the basic brain mechanisms of categorical decisions and attention will likely give important insights into the causes and potential treatments for disorders involving these cognitive and perceptual abilities.