Long-range processing in dorsal-occipital cortex

背枕皮质的长程处理

• 批准号: 6624183
• 负责人: CHRISTOPHER W TYLER
• 金额: $ 36.7万
• 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/6624183
• 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）许多组织和职能 人类大脑皮层的区域开始被理解，特别是在 感觉处理区域，例如枕叶。该提案的重点是 枕叶皮层最不为人所知的部分，它的背外侧部分。的 枕叶、颞叶和顶叶围绕着这个区域， 研究，但其性质在很大程度上是模糊的。例如，背外侧 在功能磁共振成像（functional Magnetic MRI）中， 共振成像）研究显示多达9个内侧和腹侧视网膜定位 枕叶皮层的区域关于这个功能的一些提示 背外侧区表明，它可能参与处理的 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、对称性和完形 关系。这个有趣的观点表明，这种配置 连接被处理，既不是在已知的视网膜定位区，也不是在 枕颞叶腹侧优势客体反应区 皮层各种类型的对称，特别是，构成了一个 基于数学运算符的构型属性似乎很吸引人， 直接影响到感知 理解枕叶外侧皮质功能的一个关键动机 (LOC)它会因为血液供应而受到局部损伤， 大脑后动脉（PCA）我们有一个特别的缺陷， 在患有该动脉分支梗死的患者中， 其他随机模式的对称性感知的特定损失（但最小 视野损失），这意味着一个高水平的皮层位点的处理 模式对称性。了解了这些功能， 为特定功能损失和改进的管理制定测试 这样的病人。 该提案涉及四个项目。首先，我们将构建一个电池， 基于功能性磁共振成像研究，已知刺激激活部分脑区。接下来我们将 重点是对称性在对象处理中的作用，我们发现， 主要位于中枕回（在小脑上）。此夕h 皮质功能磁共振成像在对称性处理的敏感性将比较 各类自然和人工物体，以确定是否关键 对称性的远程处理机制的方面基于 视觉图像中的对称性或从任何视角推广到物体的对称性 角度，或特定于特定对象（如面）。第三次fMRI 项目将开发探针刺激，以确定刺激的敏感性 对于邻近假定对称区域的其他皮质区域 其功能仍然神秘。这些探针刺激将涉及 各种视觉方式的长距离空间交互作用， 在处理物体和面孔时的构形效应。最终 该项目将引入一个临床组成部分， 相关病变的神经系统患者，以及比较研究 在匹配的对照组中。