Mechanisms of Intermediate Distance Space Perception

描述(由申请人提供)：相当大比例的人类活动涉及空间定向、移动和行动，发生在距离观察者约2至25米的关键空间跨度内。然而，在中等距离范围内完美地执行这些活动的能力背后的机制还没有被很好地理解，尽管每当这些能力因脑损伤而受损时，人们就会意识到这一点。空间知觉是如何受损的？回答这个问题的一个关键是理解人类在中等距离范围内的感知是如何相对于物理空间被引用的。Gibson(1950)对这个问题提供了早期的理论答案，他提出中距离范围内的空间知觉受到地面结构的高度影响。目前的提议除了提出新的假设以揭示中距离范围内空间感知的基本感知机制外，还提出了一些支持地面参考想法的经验证据。将讨论三个广泛定义的问题。这些是：1.视觉系统如何定义用于距离判断的地面参考框架？2.如何确定和校准人眼水平？3.如何定位地面上的物体？这项研究将在现实和虚拟现实环境中进行。后者不仅提供了可控的刺激环境，还将为设计高沉浸质量的虚拟现实系统提供有价值的见解，这将有助于那些对虚拟现实系统的职业和治疗应用感兴趣的人。最重要的是，这项研究将推进关于地面如何由大脑表示，以及如何将其用作定位物体的参照系的知识，这是理解空间感知和认知的重要一步。

DESCRIPTION (provided by applicant): A significant proportion of human activities involving space orientation, locomotion and action occur over a critical span of space of about 2 to 25m from the observer. Yet, the mechanisms underlying the abilities to flawlessly perform these activities in the intermediate distance range are not well understood, though appreciated whenever the abilities are impaired due to brain injuries. How is space perception impaired? A key to answering this question is to understand how human perception in the intermediate distance range is referenced relative to the physical space. An early theoretical answer to this question was provided by Gibson (1950), who proposed that space perception in the intermediate distance range is highly influenced by the structure of the ground surface. The current proposal presents some empirical evidence to support the ground reference idea, in addition to presenting new hypotheses to uncover the perceptual mechanisms underlying space perception in the intermediate distance range. Three broadly defined issues will be addressed. These are: 1. How does the visual system define the ground surface reference frame for distance judgment? 2. How is the eye level determined and calibrated? 3. How is an object above the ground surface localized? This research will be conducted both in the real and virtual reality environments. The latter not only provides for a controlled stimulus environment, but will also provide valuable insights into designing virtual reality systems with high immersion quality, which will be of benefit to those interested in the vocational and therapeutic usage of the virtual reality systems. Above all, this research will advance the knowledge of how the ground surface is represented by the brain, and how it is employed as a reference frame for localizing objects, which is an important step to understanding space perception and cognition.