Mechanisms of Intermediate Distance Space Perception

描述（由申请人提供）：很大一部分涉及空间定向、移动和行动的人类活动发生在距离观察者约2至25米的临界空间跨度内。然而，在中距离范围内完美完成这些活动的能力背后的机制还没有得到很好的理解，尽管当这种能力因脑损伤而受损时，我们就会认识到这一点。空间感知是如何受损的？回答这个问题的关键是理解人类在中距离范围内的感知是如何相对于物理空间进行引用的。Gibson（1950）为这个问题提供了一个早期的理论答案，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。本文提出了一些经验证据来支持地面参考的观点，并提出了新的假设来揭示中距离范围内空间感知的感知机制。会议将讨论三个广泛定义的问题。它们是：1；视觉系统如何定义地面参考系来判断距离？2. 如何确定和校准眼位？3. 地面上的物体是如何定位的？本研究将在真实和虚拟现实环境中进行。后者不仅提供了一个可控的刺激环境，而且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，这将有利于那些对虚拟现实系统的职业和治疗用途感兴趣的人。最重要的是，这项研究将推进对地面如何被大脑表征，以及如何作为物体定位的参考框架的认识，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.