PERCEPTUAL MECHANISMS OF VISUOSPATIAL ORIENTATION

视觉空间定向的感知机制

基本信息

批准号：
6372442
负责人：
CHARLES J DUFFY
金额：
$ 28.71万
依托单位：
UNIVERSITY OF ROCHESTER
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-04-15 至 2005-03-31
项目状态：
已结题

项目摘要

Visuospatial orientation is the knowledge of one's location that allows navigation through the environment. It relies on optic flow to monitor the path of self-movement and object vision to monitor relative position. If optic flow and object cues for spatial orientation are processed separately in dorsal and ventral visual areas, they might function separately and interact differently with memory, motor control, and vestibular systems. I will assess the independence of optic flow and object vision in visuospatial processing by testing three specific hypotheses: 1) That object vision dominates heading memory because of strong connections between ventral visual areas and the hippocampus. 2) That optic flow dominates heading motor control because of strong connections between dorsal visual areas and motor centers. 3) That real movement interacts more with optic flow than object cues because cortical vestibular centers are more closely connected to dorsal visual areas. I will test these hypotheses in normal subjects by presenting optic flow and object stimuli as cues about the heading of self-movement in three experiments: 1) pointing to a remembered heading, 2) manual steering toward a target heading, and 3) heading perception during real translational movement. My goals are to characterize the perceptual mechanisms of visuospatial orientation, relate cognitive function to neural organization, and examine the applicability of the dual pathways view to visuospatial information processing. I will use the same approach in a parallel analysis of visuospatial disorientation, a common and debilitating aspect of Alzheimer's disease (AD). These studies will test whether impaired optic flow perception in AD is separate from deficits in object vision by identifying double dissociations between impaired cue use in visuospatial tasks. My goal is to integrate visual psychophysics and the analysis of visuospatial deficits to develop the requisite scientific foundation for clinical studies of visuospatial disorientation in AD.

视觉空间定向是对一个人的位置的了解，可以在环境中进行导航。它依靠光流来监测自身运动的路径，依靠物体视觉来监测相对位置。如果光流和空间定向的物体线索在背侧和腹侧视觉区域分别处理，它们可能会单独发挥作用，并与记忆、运动控制和前庭系统以不同的方式相互作用。我将通过测试三个具体假设来评估视空间处理中视流和物体视觉的独立性：1）由于腹侧视觉区域和海马体之间的紧密联系，物体视觉主导着方向记忆。 2）由于背部视觉区域和运动中心之间的紧密联系，光流主导了航向运动控制。 3）真实的运动与光流的相互作用比物体线索更多，因为皮质前庭中心与背侧视觉区域的联系更紧密。我将在三个实验中通过将光流和物体刺激作为有关自我运动方向的线索，在正常受试者中测试这些假设：1）指向记住的方向，2）手动转向目标方向，3）方向感知在真正的平移运动期间。我的目标是描述视觉空间定向的感知机制，将认知功能与神经组织联系起来，并检查双路径观点对视觉空间信息处理的适用性。我将使用相同的方法对视觉空间定向障碍进行并行分析，视觉空间定向障碍是阿尔茨海默病 (AD) 的一个常见且令人衰弱的方面。这些研究将通过识别视觉空间任务中线索使用受损之间的双重分离来测试 AD 中的光流感知受损是否与物体视觉缺陷分开。我的目标是将视觉心理物理学和视觉空间缺陷分析结合起来，为 AD 视觉空间定向障碍的临床研究奠定必要的科学基础。