NEGLECT AND SPATIAL REPRESENTATIONS

描述：拟议研究的目标是调查亚型 在理论上、数学上和空间上的片面忽视 神经解剖学上。忽视空间和空间视角的传统观点 表示作为一个单一的同质实体，通过它注意力 导演。这些描述不能解释最近的一些经验 观察。推动这项调查的中心假设是 神经系统构建了多种空间表征，而忽视可能 出现在这些不同的表示中。这些假设 表达定位于查看者、环境和对象。 我们将在脑损伤患者和 正常对照受试者。第一组实验解决了 以观众为中心的参照系，检查忽略的调制 头部相对于躯干位置的变化。第二 一系列以环境为中心的参照系的实验， 考察了整体位置的变化对忽视的调节作用 身体与环境的关系。第三组实验，即 解决对象中心忽视，检查改变对忽视的调制 在与新生物体相关的视觉纹理和纹理上。每套 实验的重点是通过不同的模式进行调制 (本体感觉、前庭感觉和视觉质地)来测试 多重空间表征的中心假设。准确地说 表征忽略子类型，我们将开发和应用数学 数据分析。前两组实验将使用心理物理学 幂函数和第三个实验将介绍逻辑的使用 回归求导Sigmoid函数。从详细分析 解剖这些患者的脑部病变，我们将调查定侧 解剖基础--空间注意障碍的差异 空间注意在三维空间中的中介作用，以及空间注意的神经中介作用 功能模块化。 简而言之，拟议的调查应提供重要证据 加深我们对以下方面的理解：1)不同感官的输入 通道有助于多个空间表示，2)精确 忽视行为的数学分析，以及3)神经底物 潜在的忽视亚型。

DESCRIPTION: The goal of the proposed research is to investigate subtypes of unilateral spatial neglect theoretically, mathematically and neuroanatomically. Traditional accounts of neglect view space and spatial representations as a single homogeneous entity through which attention is directed. These accounts cannot explain a number of recent empiric observations. The central hypothesis driving this investigation is that the nervous system constructs multiple spatial representations, and neglect may occur within these different representations. These hypothesized representations are anchored to the viewer, the environment and the object. We will conduct three sets of experiments in brain damaged patients and normal control subjects. The first set of experiments which addresses viewer centered reference frames, examines the modulation of neglect by changes in the position of the head in relation to the trunk. The second set of experiments, which addresses environment centered reference frames, examines the modulation of neglect by changes in the position of the entire body in relation to the environment. The third set of experiments, which addresses object center neglect, examines modulation of neglect by changes in visual grain and texture in relation to nascent objects. Each set of experiments will focus on modulation by a different modality (proprioception, vestibular sensation and visual texture) to test the central hypothesis of multiple spatial representations. To precisely characterize neglect subtypes we will develop and apply mathematical analyses of data. The first two sets of experiments will use psychophysical power functions and the third experiment will introduce the use of logistic regression to derive sigmoid functions. From a detailed analysis of the anatomy of these patients' brain lesions, we will investigate lateralizing differences in disorders of spatial attention, the anatomic substrate mediating spatial attention in three dimensions, and the neural mediation of functional modularity. In short, the proposed investigations should provide important evidence to advance our understanding of: 1) how input from different sensory modalities contribute to multiple spatial representations, 2) precise mathematical analyses of neglect behavior, and 3) the neural substrates underlying neglect subtypes.