Cortical Mechanisms of Visual Category Recognition and learning

描述（由申请人提供）：人类和其他高级动物具有令人印象深刻的能力，能够识别各种感官刺激的行为意义或类别成员。这种能力是至关重要的，因为它使我们能够对我们在与环境的互动中遇到的持续不断的刺激和事件做出适当的反应。这种能力被许多大脑疾病和条件（如阿尔茨海默病、精神分裂症和中风）所破坏。当然，我们并不是生来就有一个内置的有意义的类别库，比如“桌子”和“椅子”，我们预先设定了识别这些类别的程序。相反，我们通过经验学会识别这些刺激的意义。这里提出的研究目标是更详细地了解视觉刺激的行为相关性或类别隶属性的学习和识别的大脑机制。最近，我们发现后顶叶皮层在视觉刺激的类别隶属性编码中起作用。在这些研究中，我们记录了顶叶皮层的神经元在执行分类任务时的情况，其中360个运动方向被分为两个任意的类别，并由一个习得的类别边界划分。这些记录表明，顶叶神经元对刺激物进行了稳健的分类编码，表明顶叶视觉表征可以反映视觉刺激物学习意义的抽象信息。本研究的目的是建立对LIP类别表征的机制理解，并比较LIP与参与学习和编码视觉刺激行为意义的其他大脑区域（如前额叶皮质）的作用。虽然人们对大脑如何处理简单的感官特征（如颜色、方向和运动方向）了解很多，但对大脑如何学习和代表刺激的意义或类别知之甚少。更好地了解视觉学习和分类对于解决一些脑部疾病和病症（例如中风、阿尔茨海默病、注意力缺陷障碍和精神分裂症）至关重要，这些疾病和病症使患者在需要视觉学习、识别和/或评估和适当响应感官信息的日常任务中受损。弗里德曼博士研究的长期目标是通过帮助发展对学习、记忆和识别基础的大脑机制的详细了解，帮助指导这些基于大脑的疾病和障碍的下一代治疗。这些研究也与理解和解决学习障碍有关，例如注意力缺陷障碍和阅读障碍，这些障碍影响了很大一部分学龄儿童和年轻人。因此，更详细地了解学习和注意力的基本大脑机制，可能会对涉及这些认知能力的疾病的原因和潜在治疗方法提供重要的见解。公共卫生相关性：我们识别视觉刺激的行为意义或意义的能力对于计划和执行成功的行为以响应我们的环境至关重要。因此，我们研究的长期目标是提供对视觉刺激的行为意义的学习和识别背后的大脑过程的详细和机械的理解。详细了解这些大脑机制对于理解和最终解决学习、记忆和识别方面的严重缺陷至关重要，这些缺陷经常伴随大脑疾病和中风、精神分裂症和阿尔茨海默病等疾病。

DESCRIPTION (provided by applicant): 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 and stroke, 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 of the behavioral relevance, or category membership, of visual stimuli. Recently, we found evidence that the posterior parietal cortex plays a role in encoding the category membership of visual stimuli. In these studies, we recorded from neurons in the parietal cortex during performance of a categorization task in which 360: of motion directions were grouped into two arbitrary categories that were divided by a learned category boundary. These recordings revealed that parietal neurons 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 LIP category representations and to compare the roles of LIP and other brain areas (e.g. prefrontal cortex) that are involved in learning and encoding the behavioral significance of visual stimuli. 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, and schizophrenia) 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 Dr. Freedman's research is to help 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. PUBLIC HEALTH RELEVANCE: Our ability to recognize the behavioral significance, or meaning, of visual stimuli is essential for planning and carrying out successful behaviors in response to our surroundings. Thus, the long term goal of our research is to provide a detailed and mechanistic understanding about the brain processes that underlie the learning and recognition of the behavioral significance of visual stimuli. A detailed understanding of these brain mechanisms is critical for understanding and ultimately addressing the profound deficits of learning, memory and recognition that frequently accompany brain diseases and conditions such as stroke, schizophrenia and Alzheimer's disease.