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临床试验/NCT05419713
NCT05419713招募中不适用

Visual Mechanisms of Intermediate Distance Space Perception During Self-motion

University of Louisville2 个研究点 分布在 1 个国家目标入组 180 人开始时间: 2021年9月30日最近更新:
适应症
干预措施

试验速览

阶段
不适用
状态
招募中
入组人数
180
试验地点
2
主要终点
Visual mechanisms of intermediate distance space perception (distance) before and after self-motion

研究概览

简要总结

The ability to judge the locations of various objects from oneself during self-motion in the intermediate distance range (~2-25m) is crucial for successful performance of activities of daily living, such as walking and driving. However, little is known about the mechanisms of visual space perception involved in judging distance, the focus of this project, in the planning and/or execution of self-motion in the natural 3D environment. The theoretical knowledge to be gained from this project will contribute to the scientific literature and provide insights into how eye and neurological defects could impair visual space perception, wayfinding, and mobility.

详细描述

Every day human subjects rely on their vision to judge the absolute distances of objects around them to plan and guide their actions, such as walking and driving. This, way-finding, process of ascertaining one's position and planning for possible routes of actions cannot be accomplished without reliable perception of visual space in the intermediate distance range (~2-25m from the observer). Thus, the broad long-term objective of this project is to uncover the mechanisms underlying intermediate distance space perception that supports distance judgment.

Yet, less is known about the underlying mechanisms of intermediate distance space perception compared to those of near space perception (<2m). Moreover, extant knowledge is predominantly obtained from testing static observers, making it difficult to generalize to the more common situation where observers plan and execute self-motion. The latter situation is more complex because self-motion is accompanied by retinal image motion of static objects in the surrounding environment, potentially requiring the visual system to simultaneously track the locations of all objects in the environment. The visual system also requires more processing capacity because it has to simultaneously compute the visual space representation, explore the environment, implement motor controls, etc. Clearly, both challenges - coding complexity and capacity limitation - could pose as potential threats to our ability to efficiently judge absolute distances and implement actions. This project hypothesizes the visual system overcomes both challenges by: (a) spatially updating the moving observer's position using an allocentric, world-centered spatial coordinate system for representing visual space, and (b) use spatial working memory (spatial-image) during spatial updating. The investigators will examine both hypotheses in three specific aims.

Aim 1: Investigate the implementation of the allocentric, world-centered spatial coordinate system

Aim 2: Investigate the factors affecting the spatial updating of visual space

Aim 3: Investigate the role of spatial-image memory in visual space perception

研究设计

研究类型
Interventional
分配方式
Na
干预模型
Single Group
主要目的
Basic Science
盲法
None

入排标准

年龄范围
18 Years 至 40 Years(Adult)
性别
All
接受健康志愿者

入选标准

  • Adults (up to 40 years of age)
  • Children (18 years and older)
  • Normal, or corrected-to-normal, visual acuity (at least 20/20)
  • Stereo acuity (<20 arc sec).

排除标准

  • Self-reported history of visual and eye diseases
  • Physical movement restrictions.
  • Vulnerable populations such as pregnant women will be excluded owing to the extensive time commitment required of the subjects.

研究组 & 干预措施

Visual scences

Experimental

Lit target locations in visual environment will be varied and subjects' perceived locations will be measured.

干预措施: Visual Stimuli for Space Perception (Other)

结局指标

主要结局

Visual mechanisms of intermediate distance space perception (distance) before and after self-motion

时间窗: During procedure, an average of 10 sec.

Subjects will judge perceived distances (cm) of test targets from themselves before self-motion to establish a baseline measure. Subjects will then undergo self-motion for an average of 10 sec, and stop at a predetermined location. Then subjects will again judge the perceived distance (cm) of test targets after the self-motion. The change in perceived distance (cm) from baseline will reveal if their perception is affected by environmental factors, internal perceptual process and/or cognitive process.

Visual mechanisms of intermediate distance space perception (height) before and after self-motion.

时间窗: Druing procedure, an average of 10 sec.

Subjects will judge perceived heights (cm) of test targets relative to the floor or ceiling before self-motion to establish a baseline measure. Subjects will then undergo self-motion for an average of 10 sec, and stop at a predetermined location. Then subjects will again judge the perceived height (cm) of test targets after the self-motion. The change in perceived height (cm) from baseline will reveal if their perception is affected by environmental factors, internal perceptual process and/or cognitive process.

次要结局

未报告次要终点

研究者

申办方类型
Other
责任方
Principal Investigator
主要研究者

He Zijiang

Professor

University of Louisville

研究点 (2)

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