CONGNITIVE AND NEURAL BASES OF SPATIAL NEGLECT RECOVERY

描述(申请人提供)：注意力和行动障碍通常是由脑损伤引起的。单侧空间忽视是人类右半球局灶性脑损伤后最常见的神经行为综合征。忽视在大多数患者中都能在一定程度上自发恢复，因此是研究神经康复机制的理想模型。这项建议的长期目标是了解空间忽视的神经和认知机制，它的恢复，以及它们如何与正常的注意机制相关。我们的主要假设是，忽视反映了位于后顶叶和额叶皮质的注意系统的故障。我们提出三个基本问题。首先，哪些加工缺陷对忽视综合症的贡献最大，这些缺陷在解剖学上是可分离的吗？例如，与空间注意和感知、定向运动动作和觉醒相关的缺陷的相对重要性是什么，它们是否映射到不同的大脑区域？第二，这些加工缺陷中的哪一个(S)与忽视的恢复更密切相关？第三，忽视恢复的神经关联是什么？恢复取决于受损和/或非受损半球的激活恢复程度，还是取决于两个半球的活动平衡？为了回答这些问题，我们在一大组单侧半球中风的忽视患者中进行了前瞻性的纵向行为、解剖和功能磁共振成像(MRI)研究，并对注意系统核心区病变的患者进行了几项心理物理实验。

DESCRIPTION (provided by applicant): Disorders of attention and action are often produced by brain injury. Unilateral spatial neglect is the most common neurobehavioral syndrome following focal brain injury to the human right hemisphere. Neglect spontaneously recovers to some extent in most patients, and therefore represents an ideal model for studying mechanisms of neurological recovery. The long-term goal of this proposal is to understand the neural and cognitive mechanisms of spatial neglect, its recovery, and how they relate to normal attentional mechanisms. Our overarching hypothesis is that neglect reflects the malfunction of attentional systems that are localized in posterior parietal and frontal cortex. We ask three basic questions. First, what processing deficits most contribute to the syndrome of neglect, and are these deficits anatomically dissociable? For example, what is the relative importance of deficits related to spatial attention and perception, directional motor actions, and arousal, and do they map to different brain regions? Second, which of these processing deficit(s) is/are more closely associated with the recovery of neglect? Third, what are the neural correlates of neglect recovery? Does recovery depend on the degree to which activation recovers in the lesioned and/or non-lesioned hemisphere, or does it depend on the balance of activity across the hemispheres? To answer these questions we carry out a prospective longitudinal behavioral, anatomical and functional magnetic resonance imaging (MRI) study in a large group of neglect patients with single unilateral hemispheric strokes, and several psychophysical experiments in patients with lesions in core areas of the attention system.