Testing the effects of visual field on perceptual organization as a potential source of unexplained visual dysfunction in macular degeneration

项目摘要 这项工作的目标是表征视觉过程中转换2维空间的变化 视网膜图像转化为基于对象的世界的3维表示，作为位置的函数 视野。这些过程--统称为知觉组织--对成功至关重要 更复杂的视觉任务，包括重要的日常任务，如阅读，识别个人，以及 跟踪屏幕上或世界上的动态事件。MOST的基本神经生理学 知觉组织的基本组成部分表明知觉组织是 与中央区域相比，视野的外围区域中的信息相对较差。我们将测试 这项工作中的假设。这项研究的部分意义在于黄斑变性，这是 65岁以上人群失明的主要原因，预计将影响近200万人 在美国，到2020年，以视野中央区域渐进性视力丧失为特征。 因此，黄斑变性患者必须学会依赖周围的信息，并且 许多针对该病的干预措施都集中在增加外周信息的大小以弥补 已知的空间分辨率随偏心而降低。尽管这些干预措施取得了成功，但改善 对外周刺激敏感，许多患者继续遭受更复杂的功能障碍，并对 日常生活中，阅读和识别人脸等任务。我们假设这其中的一个重要部分 残留功能障碍是由于需要依赖外围知觉组织造成的，这种组织产生了相对 糟糕的3D世界模型，即使边缘和其他低级特征是完全可以区分的。这 项目将(1)量化一组四个基本的知觉组织过程，这些过程直接与 简单的神经生理机制已经被识别，并为基本的 假设，(2)检验依赖于知觉的重要下游过程的假设 组织-基于对象的注意-在更多的边缘区域的有效性也会降低 和(3)检验知觉组织的变化作为位置的函数的假设 视野可以预测个体观察者基于物体的注意的变化。如果这项工作提供了 支持正在测试的基本假设，然后后续工作将把测量扩展到患者 并询问他们的特定功能障碍是否可以通过依赖 相对较差的感知组织，如果是这样的话，寻求制定干预措施，要么改善要么 专门针对这种依赖进行补偿。

Project Summary The goal of this work is to characterize changes in visual processes that transform the 2-dimensional retinal image into object-based 3-dimensional representations of the world as a function of location within the visual field. These processes—referred to collectively as perceptual organization—are critical to the success of more complex visual tasks including important everyday tasks like reading, recognizing individuals, and following dynamic events on a screen or in the world. The underlying neurophysiology of the most fundamental components of perceptual organization suggest the hypothesis that perceptual organization is relatively poor for information in peripheral regions of the visual field compared to central regions. We will test that hypothesis in this work. Part of the significance of this work is that macular degeneration, which is the leading cause of blindness in people over the age of 65, and is expected to affect nearly 2 million individuals in the U.S. by 2020, is characterized by progressive loss of vision in central regions of the visual field. Individuals with macular degeneration therefore have to learn to rely on information in their periphery, and many interventions for the disease focus on increasing the size of peripheral information to compensate for known decreases in spatial resolution with eccentricity. Despite the success of these interventions to improve sensitivity to peripheral stimuli, many patients continue to suffer dysfunction in more complex, and critical for everyday life, tasks such as reading and recognizing faces. We hypothesize that an important part of this residual dysfunction is caused by the need to rely on peripheral perceptual organization which yields relatively poor 3D models of the world, even if edges and other low-level features are perfectly discriminable. This project will (1) quantify a set of four basic perceptual organization processes that are directly relatable to the simple neurophysiological mechanisms that have been identified and that provide motivation for the basic hypothesis, (2) test the hypothesis that an important downstream process that depends on perceptual organization – object-based attention — also decreases in effectiveness in more peripheral regions of the visual field and (3) test the hypothesis that changes in perceptual organization as a function of location in the visual field can predict changes in object-based attention within individual observers. If this work provides support for the basic hypotheses being tested, then follow-up work will extend the measurements to patients with central visual-field loss and ask whether their specific dysfunctions can be accounted for by reliance on relatively poor perceptual organization and if so, seek to develop interventions that either improve or compensate specifically for this dependence.