Long-range processing in dorsal-occipital cortex

背枕皮质的长程处理

• 批准号: 6472891
• 负责人: CHRISTOPHER W TYLER
• 金额: $ 36.15万
• 依托单位: SMITH-KETTLEWELL EYE RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-05-01 至 2006-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6472891
• 关键词: behavioral /social science research tag; bioimaging /biomedical imaging; brain imaging /visualization /scanning; brain injury; brain mapping; clinical research; computer data analysis; form /pattern perception; functional magnetic resonance imaging; human subject; imagery; motion perception; neural information processing; neuropsychological tests; neuropsychology; occipital lobe /cortex; perception disorder; psychophysiology; space perception; visual perception

DESCRIPTION: (provided by applicant) The organization and functions of many regions of the human cortex are beginning to be understood, particularly in sensory processing areas such as the occipital lobe. This proposal focuses on the least-known part of occipital cortex, its dorsolateral segment. The occipital, temporal and parietal areas surrounding this region are well studied, yet its properties are largely obscure. For example, the dorsolateral segment shows little or no retinotopic mapping in fMRI (functional Magnetic Resonance Imaging) studies that reveal up to 9 medial and ventral retinotopic areas in the occipital cortex. The few hints as to the function of this dorsolateral area suggest that it may be involved in the processing of the configurational connections required for object processing of various types. These processes include pattern self-similarity, symmetry and Gestalt relationships. This interesting viewpoint suggests that such configurational connections are processed, neither in a known retinotopic area nor in the predominant object-responsive area in the ventral parts of occipitotemporal cortex. Symmetries of various types, in particular, constitute a configurational property based on mathematical operators that seem to appeal directly to perception. A key motivation for understanding the functions of lateral occipital cortex (LOC) is that it is subject to local damage by virtue of its blood supply from the posterior cerebral artery (PCA). One particular deficit that we have identified in patients with infarctions of branches of this artery is a specific loss in symmetry perception of otherwise random patterns (but minimal visual field losses), implying a high-level cortical locus for the processing of pattern symmetries. This knowledge of the functions of LOC will allow the development of tests for particular functional losses and improved management of such patients. The proposal is devoted to four projects. First we will construct a battery of stimuli known to activate parts of LOC based on fMRI studies. Next we will focus on the role of symmetry in object processing, which we have found to be localized principally to the middle occipital gyrus (on the LOC). Further, the cortical fMRI sensitivities in symmetry processing will be compared across various classes of natural and artificial objects to determine whether the key aspects of the long-range processing mechanisms for symmetry are based on symmetry in the visual imageor generalized to object symmetry from any viewing angle, or are specific to particular objects such as faces. The third fMRI project will be to develop probe stimuli to determine stimulus sensitivities for other cortical regions adjacent to the putative area for symmetry processing whose functions remain mysterious. These probe stimuli will involve long-range spatial interactions of various visual modalities and configurational effects in the processing of objects and faces. The final project will introduce a clinical component, quantifying symmetry-blindness in neurological patients with relevant lesions, together with comparison studies in matched controls.

描述：（由申请人提供）许多机构的组织和职能 人们开始了解人类皮层的区域，特别是 感觉处理区域，例如枕叶。该提案的重点是 枕叶皮质最不为人所知的部分，即其背外侧部分。这 该区域周围的枕叶、颞叶和顶叶区域状况良好 研究人员对其进行了研究，但其属性在很大程度上是模糊的。例如，背外侧 片段在功能磁共振成像（功能性磁 共振成像）研究揭示了多达 9 个内侧和腹侧视网膜专题 枕叶皮质区域。关于此功能的一些提示 背外侧区域表明它可能参与了 各种类型的对象处理所需的配置连接。 这些过程包括模式自相似性、对称性和格式塔 关系。这个有趣的观点表明，这种配置 连接被处理，既不在已知的视网膜主题区域，也不在 枕颞腹侧的主要物体反应区 皮质。特别是，各种类型的对称性构成了 基于数学运算符的配置属性似乎很有吸引力 直接到感知。 了解外侧枕叶皮层功能的关键动机 （LOC）是由于其血液供应而受到局部损伤 大脑后动脉（PCA）。我们有一项特殊的赤字 在患有该动脉分支梗塞的患者中确定的是 其他随机模式的对称性感知的特定损失（但最小 视野损失），意味着处理的高级皮质位点 的图案对称性。了解 LOC 的功能将允许 开发针对特定功能损失的测试并改进管理 此类患者。 该提案致力于四个项目。首先我们将构建一个电池 根据功能磁共振成像研究，已知刺激可以激活部分 LOC。接下来我们将 关注对称性在对象处理中的作用，我们发现它是 主要位于枕中回（LOC 上）。此外， 将比较对称处理中的皮质功能磁共振成像敏感性 各类自然和人造物体判断是否关键 对称性的远程处理机制的各个方面基于 视觉图像中的对称性或推广到任何观察的物体对称性 角度，或者特定于特定对象，例如面部。第三次功能磁共振成像 项目将开发探针刺激以确定刺激敏感性 对于与假定的对称区域相邻的其他皮质区域 其功能仍然神秘的处理。这些探针刺激将涉及 各种视觉方式的长距离空间相互作用 物体和面部处理中的构形效应。决赛 该项目将引入临床成分，量化对称性失明 有相关病变的神经系统患者，以及比较研究 在匹配的控件中。