Abstract Falling from heights is the primary cause of death and injuries at construction sites. As loss of balance has a fundamental effect on falling, it is important to understand postural regulation behavior during construction tasks at heights, especially those that require precise focus in an upright standing position (therefore, a dual-task demand on focus). Previous studies examined body sway during a quiet stance and dual tasks to understand latent factors affecting postural balance. Despite the success of these studies in discovering underlying factors, they lack a comprehensive analysis of a task's simultaneous cognitive load, postural sway, and visual depth. To address this limitation, this paper aims to examine construction workers' postural stability and task performance during the execution of visual construction tasks while standing upright on elevated platforms. To that end, two non-intrusive neurophysiological tests, a hand-steadiness task (HST) and a pursuit task (PT), were developed for construction tasks in a virtual environment (VE) as performance-based means to assess the cognitive function of workers at height. Workers' postural stability was measured by recording the mapped position of the Center of Pressure (COP) of the body on a posturography force plate, and the postural sway metrics subsequently calculated. A laboratory experiment was designed to collect postural and task performance data from 18 subjects performing the two batteries of tests in the virtual environment. The results demonstrated a significant decrease in the Root-Mean Square (RMS) of COP along the anterior-posterior axis during the Randomized Pursuit Task (RPT) and maximum body sway of the center of pressure (COP) in the mediolateral direction during both tests. Also, subjects exposed to high elevation predominately exhibit higher accuracy for RPT (P-value = 0.02) and lower accuracy for HST (P-value = 0.05). The results show that the combination of elevation-related visual depth and low-complexity dual tasks impairs task performance due to the elevation-induced visual perturbations and anxiety-driven motor responses. On the other hand, in the absence of visual depth at height, high task complexity surprisingly improves the pursuit tracking performance. As expected, during both tasks, alterations in postural control were manifested in the form of a body sway decrement as a compensatory postural strategy for accomplishing tasks at high elevation.

中文翻译：

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用于评估建筑工人在虚拟高度下的任务表现的神经生理学测试

摘要 高处坠落是建筑工地死伤的主要原因。由于失去平衡对坠落有根本性的影响，因此了解高空施工任务中的姿势调节行为非常重要，尤其是那些需要在直立姿势下精确对焦的情况（因此，双任务需要对焦）。以前的研究检查了安静姿势和双重任务期间的身体摇摆，以了解影响姿势平衡的潜在因素。尽管这些研究在发现潜在因素方面取得了成功，但它们缺乏对任务同时发生的认知负荷、姿势摇摆和视觉深度的综合分析。为了解决这个限制，本文旨在检查建筑工人的 直立在高架平台上执行视觉施工任务期间的姿势稳定性和任务性能。为此，为虚拟环境 (VE) 中的构建任务开发了两个非侵入性神经生理学测试，即手部稳定性任务 (HST) 和追踪任务 (PT)，作为评估认知功能的基于性能的手段。工人在高处。工人的姿势稳定性是通过在姿势图测力板上记录身体压力中心 (COP) 的映射位置来测量的，然后计算姿势摇摆指标。一项实验室实验旨在收集 18 名受试者在虚拟环境中进行两组测试的姿势和任务表现数据。结果表明，在随机追踪任务 (RPT) 期间，COP 沿前后轴的均方根 (RMS) 显着降低，并且在两次测试期间，压力中心 (COP) 在内侧方向的最大身体摆动. 此外，暴露于高海拔的受试者主要表现出较高的 RPT 准确度（P 值 = 0.02）和较低的 HST 准确度（P 值 = 0.05）。结果表明，由于海拔引起的视觉扰动和焦虑驱动的运动反应，海拔相关的视觉深度和低复杂性双重任务的结合会损害任务绩效。另一方面，在缺乏高度视觉深度的情况下，高任务复杂性令人惊讶地提高了追踪性能。正如预期的那样，在这两项任务中，