Neural Substrates Of Stimulus Recognition And Associatio

刺激识别和联想的神经基质

• 批准号: 6823947
• 负责人: ELISABETH A MURRAY
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF MENTAL HEALTH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6823947
• 关键词: amygdala; association learning; entorhinal cortex; hippocampus; memory; neural information processing; prefrontal lobe /cortex; sensory mechanism; stimulus /response; visual perception

The Section on the Neurobiology of Learning & Memory of the Laboratory of Neuropsychology, NIMH, studies the neural mechanisms underlying perception, learning, memory, and other cognitive processes. To this end, we have examined the effects of selective cerebral ablations and disconnections on different types of learning and memory in macaque monkeys. Overview. The "ventral visual stream" is a group of striate, prestriate, and inferior temporal cortical fields devoted to processing visual information about objects. While the processing of visual information is carried out by these visual cortical fields, the actual storage of visual representations in monkeys appears to depend in large part on a strip of cortex lying at the base of the medial temporal lobe. This region is comprised of the entorhinal cortex and perirhinal cortex, abbreviated here as "rhinal cortex". The rhinal cortex appears to be critical for accurate stimulus identification, stimulus recognition, and stimulus-stimulus association, including both intramodal stimulus-stimulus associations and crossmodal ones. Furthermore, the rhinal cortex can mediate these types of information storage in the absence of the medial temporal lobe limbic structures, the amygdala and hippocampus. The rhinal cortex interacts with other brain regions to link stored stimulus representations with emotion and action. Accomplishments of the past year. Recently we have hypothesized that the perirhinal cortex contains neurons that represent complex conjunctions of visual stimulus features, and, as a consequence, that this region is important for discriminating objects under conditions of high feature overlap. An example of feature overlap is when a given visual feature or set of features is part of two different objects that need to be differentiated. We have tested this idea and have found that the perirhinal cortex is indeed important for discriminating objects when we increase "feature overlap" experimentally, either by using software to morph or "blend" two different stimuli or by specially constructing visual stimuli that have a number of features in common. By contrast, the perirhinal cortex is not necessary for visual discrimination objects when there is little or no feature overlap. Thus, the perirhinal cortex operates as part of the ventral visual stream or "what" pathway, in helping to process and store information about objects. We suggest that its special contribution to this kind of processing is the representation of complex conjunctions of features, as opposed to any special computational function it might possess. Once a visual item is identified, it can be associated with other kinds of information, for example with emotions (or affective valence), spatial locations and responses. Recent work from this and other laboratories indicates that the amygdala is important for associating a visual stimulus with its affective valence, and further, that the amygdala must interact with the orbital prefrontal cortex to enable animals to choose advantageously under conditions in which the outcome of their actions may be changing for the better or worse. Additional studies have extended the work on visual information processing and storage by examining the role of various prefrontal cortical fields in associating visual stimuli with specific actions. This kind of learning probably underlies the acquisition of language, especially the association between the written word and the motor programs necessary to produce speech. At least two prefrontal cortical areas, the ventral prefrontal cortex and the orbital prefrontal cortex, are important for establishing this kind of rapid, arbitrary linking of visual stimuli with actions. As far as we can discern, the necessary roles for the prefrontal areas is the association between vision and action, and the acquisition of rules guiding those kinds of behavior, as opposed to the visual identification of the object or the production of the response, per se. In the past year we have published 13 reports, including 4 peer-reviewed primary research articles together with several refereed review and encyclopedia articles. Significance to biomedical research and mental health. Memory loss typically accompanies strokes and viral infections of the brain, and is a central feature of certain diseases such as Alzheimer's Disease and AIDS dementia complex. Our research has been dedicated to understanding the functions of the key brain areas involved in information storage, including the rhinal cortex, amygdala, and hippocampus. By gaining a better understanding of the normal functional organization of these regions, we hope to reveal ways in which the disorders of memory can be understood and, potentially, ways in which the disorders can be ameliorated.

NIMH神经心理学实验室学习和记忆的神经生物学部分研究感知、学习、记忆和其他认知过程的神经机制。为此，我们研究了选择性脑消融和切断连接对猕猴不同类型学习和记忆的影响。概述。“腹侧视觉流”是一组纹状、纹前和下部的颞叶皮质区域，致力于处理有关物体的视觉信息。虽然视觉信息的处理是由这些视觉皮质区域执行的，但猴子视觉表征的实际存储似乎在很大程度上依赖于位于内侧颞叶底部的一条皮质。这一区域由内鼻皮质和鼻周皮质组成，在这里缩写为“鼻皮质”。鼻皮质似乎对准确的刺激识别、刺激识别和刺激-刺激联想至关重要，包括模式内刺激-刺激联想和跨模式刺激-刺激联想。此外，在没有内侧颞叶边缘结构、杏仁核和海马体的情况下，鼻皮质可以调节这些类型的信息存储。鼻皮质与大脑的其他区域相互作用，将储存的刺激表征与情绪和行动联系起来。过去一年的成就。最近，我们假设视网膜周围皮质含有代表视觉刺激特征的复杂连接的神经元，因此，在特征高度重叠的条件下，该区域对于区分物体是重要的。特征重叠的一个例子是当给定的视觉特征或特征集是需要区分的两个不同对象的一部分时。我们对这一想法进行了测试，发现当我们通过实验增加“特征重叠”，无论是通过使用软件变形或“混合”两个不同的刺激，还是通过特殊构造具有许多共同特征的视觉刺激，虹膜周围皮质对于辨别物体确实很重要。相比之下，当特征很少重叠或没有重叠时，视觉辨别对象不需要虹膜周围皮质。因此，嗅周皮质作为腹侧视觉流或“什么”通路的一部分，帮助处理和存储有关物体的信息。我们认为，它对这类加工的特殊贡献是对特征的复杂连接的表征，而不是它可能具有的任何特殊计算功能。一旦视觉项目被识别，它就可以与其他类型的信息相关联，例如与情绪(或情感价位)、空间位置和反应相关联。该实验室和其他实验室最近的工作表明，杏仁核对于将视觉刺激与其情感效价联系起来非常重要，此外，杏仁核必须与眼眶前额叶皮质相互作用，使动物能够在其行为结果可能变得更好或更糟的条件下做出有利的选择。其他研究通过检查各种前额叶皮质区域在将视觉刺激与特定动作相关联方面的作用，扩展了视觉信息处理和存储方面的工作。这种学习可能是语言习得的基础，特别是书面单词和产生语音所必需的运动程序之间的联系。至少有两个前额叶皮质区域，腹侧前额叶皮质和眼眶前额叶皮质，对于建立这种快速、任意的视觉刺激与动作的联系是重要的。据我们所知，前额叶的必要角色是视觉和行动之间的联系，以及获得指导这些行为的规则，而不是视觉识别对象或产生反应本身。在过去的一年里，我们发表了13篇报告，包括4篇同行评议的主要研究文章，以及几篇参考评论和百科全书文章。对生物医学研究和心理健康的意义。记忆力丧失通常伴随着中风和脑部病毒感染，是阿尔茨海默氏症和艾滋病痴呆症等某些疾病的核心特征。我们的研究一直致力于了解参与信息存储的关键大脑区域的功能，包括鼻孔皮质、杏仁核和海马体。通过更好地了解这些区域的正常功能组织，我们希望揭示理解记忆障碍的方法，并潜在地揭示改善记忆障碍的方法。