Mechanisms of Intermediate Distance Space Perception

描述（由申请人提供）：涉及空间定向、运动和行动的人类活动的很大一部分发生在距离观察者约2至25米的关键空间跨度上。然而，在中等距离范围内无障碍地进行这些活动的能力的机制还没有得到很好的理解，尽管每当由于脑损伤而导致能力受损时都会受到重视。空间感知是如何受损的？回答这个问题的一个关键是理解人类在中间距离范围内的感知是如何相对于物理空间被引用的。吉布森（1950）对这个问题给出了早期的理论答案，他提出中距离范围内的空间感知受到地面结构的高度影响。目前的建议提出了一些经验证据，以支持地面参考的想法，除了提出新的假设，以揭示潜在的空间感知在中间距离范围内的感知机制。将讨论三个定义广泛的问题。这些是：1.视觉系统如何定义地面参考系以进行距离判断？2.眼位是如何确定和校准的？3.地面上的物体是如何定位的？这项研究将在真实的和虚拟现实环境中进行。后者不仅提供了一个受控的刺激环境，但也将提供有价值的见解，设计具有高沉浸质量的虚拟现实系统，这将有利于那些有兴趣的职业和治疗使用的虚拟现实系统。最重要的是，这项研究将推进地面如何被大脑代表的知识，以及它如何被用作定位物体的参考框架，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.