Mechanisms of Intermediate Distance Space Perception

描述(申请人提供)：中等距离范围(2-25米)的视觉空间知觉具有多方面的功能。它允许观察者感知物体的3D形状、大小和位置，在空间中定位，并指导我们的行动。然而，尽管它对使观察者能够在自然环境中互动很重要，但对中等距离空间感知的基础机制的了解是不完整的。该项目的长期目标是了解空间感知的基本机制，并发现这些机制如何调节人类的空间感知和行动。关于在地面上定位物体的能力，以前的工作发现，视觉系统通过构造地面表面的表示来实现这一点，然后将其用作参考框架来定位地面上的物体。为了定位悬浮物，需要确定悬浮物与地面参考系之间的相对位置。最近的经验研究为地面空间感知的概念提供了关键证据，并导致发现了表示地面的几种基本机制。这一进展促使制定了一个更全面的理论框架，以便在目前的提案中理解视觉系统如何形成地面感知空间。其具体目标是寻求可量化的经验证据来证实和推进该框架。将调查以下三个广泛定义的问题：a.SSIP用来表示地面和其他表面的感知机制B.自上而下处理在空间感知中的作用C.定位与地面没有直接表面接触的物体研究将使用心理物理学方法来测试人类观察者，主要是在真实的3D环境中。此外，为了补充在真实3D环境中进行的研究，拟议的项目将利用虚拟现实技术来研究虚拟环境中的空间感知。这种方法不仅对控制实验刺激有用，而且还将对如何提高虚拟场景的身临其境质量有深入的了解。总体而言，从拟议项目中获得的发现和见解将在中等距离范围内推进人类空间感知科学。这也将提高我们对视觉功能受损的人所面临的视觉问题的理解。与公共健康相关：研究中等距离的空间知觉很重要，因为我们日常活动的很大一部分，如移动和导航，都是在这个距离范围内进行的。除了对知觉科学的贡献外，从这个项目中获得的知识还可以深入了解视觉缺陷患者(例如斜视和弱视)的空间感知和行动问题，以及普通人在非最佳视觉环境中遇到的问题。在拟议的项目中使用虚拟现实技术的方法有可能被改造成一种有用的工具，帮助有空间感知缺陷的人。

DESCRIPTION (provided by applicant): Visual space perception in the intermediate distance range (2-25 meters) serves a multi-faceted function. It allows the observer to perceive the 3D shapes, sizes and locations of objects, orient in space and guides our actions. Yet, despite its importance in enabling the observer to interact in the natural environment, knowledge of the mechanisms underlying space perception in the intermediate distance is incomplete. The long-term objectives of this project are to understand the basic mechanisms of space perception and to discover how these mechanisms mediate human space perception and action. Pertaining to the ability to locate an object on the ground, previous work found that the visual system achieves this by constructing a representation of the ground surface and then uses it as a reference frame to localize an object on the ground. To localize a suspended object requires determining the relative position between the suspended object and the ground reference frame. Recent empirical studies have provided critical evidence for the notion of a ground-based space perception, and led to the discovery of several fundamental mechanisms for representing the ground surface. This progress has motivated the formulation of a more comprehensive theoretical framework for understanding how the visual system forms the ground-based perceptual space in the current proposal. The specific aims are to seek quantifiable empirical proofs to substantiate and advance the framework. The following three broadly defined issues will be investigated: A. The Perceptual Mechanisms Used by the SSIP to Represent the Ground and Other Surfaces B. The Role of Top-Down Processing in Space Perception C. Locating an Object that Does Not Have a Direct Surface Contact with the Ground The research will employ the psychophysical method to test human observers, predominantly in the real 3D environment. In addition, to complement the research performed in the real 3D environment, the proposed project will investigate space perception in the virtual environment by capitalizing on the virtual reality technology. This approach is not only useful for controlling the experimental stimulation, but will also yield insights into how one can improve the immersive quality of virtual scenes. Overall, the findings and insights gained from the proposed project will advance the science of human space perception in the intermediate distance range. It will also improve our understanding of the visual problems confronted by people with compromised visual functions. PUBLIC HEALTH RELEVANCE: Research of space perception in the intermediate distance is important because a significant proportion of our daily activity, such as locomotion and navigating, are performed over this distance range. Besides its contribution to perceptual sciences, the knowledge gained from this project can provide insights into the space perception and action problems of patients with visual deficits (e.g., in strabismus and amblyopia), and the problems encountered by ordinary people in non-optimal visual environments. The approach of using the virtual reality technology in the proposed project has the potential of being adapted into a useful tool for aiding people with space perception deficits.