ABSTRACT

Objective: This study aimed to evaluate vision improvement in hypoxia following normoxic perceptual learning.

Background: Visual functions are important for flight safety. However, the potential of perceptual learning to compensate for hypoxic vision damage is unclear.

Method: Seven observers enrolled in this study and were exposed to a hypoxic (11.5% O₂) and a mesopic (3 cd/m²) environment. Visual acuity (VA) and contrast sensitivity function (CSF) were evaluated in normoxia and hypoxia before and after the 8 daily training sessions. All observers trained in a monocular sine-wave grating detection task near their individual cutoff spatial frequencies while breathing normoxic gas.

Results: The contrast sensitivity (CS) at the trained spatial frequency, the area under the log CSF (AULCSF) and VA decreased in a hypoxic environment. Additionally, all visual performances (i.e., CS, AULCSF and VA), regardless of whether they were measured in the normoxic or hypoxic condition, improved following normoxic perceptual learning. The degree of visual improvement did not differ between normoxia and hypoxia, indicating that visual improvement is completely transferable from normoxia to hypoxia.

Conclusions: Preliminary evidence suggests that visual improvement remains even under environmental changes, and perceptual learning may be a noninvasive way to compensate for vision decreases in hypoxia.

摘要

目的：本研究旨在评估常氧性知觉学习后低氧状态下视力的改善。

背景：视觉功能对于飞行安全至关重要。但是，知觉学习补偿低氧性视力损害的潜力尚不清楚。

方法：七名观察员参加了这项研究，他们暴露于低氧（11.5％O ₂）和中观（3 cd / m ²）的环境中。在每天8次训练前后的常氧和低氧状态下评估视敏度（VA）和对比敏感度函数（CSF）。所有观察员在呼吸正氧气体时都在各自的截止空间频率附近接受了单眼正弦波光栅检测任务的培训。

结果：在低氧环境下，训练的空间频率下的对比敏感度（CS），log CSF下的面积（AULCSF）和VA减小。此外，所有视觉表现（即CS，AULCF和VA），无论是在常氧状态还是低氧状态下进行测量，均会在常氧性知觉学习后得到改善。正常氧和缺氧之间的视觉改善程度没有差异，表明视觉改善可以从正常氧完全转移到缺氧。

结论：初步证据表明，即使在环境变化的情况下，视力仍保持改善，而知觉学习可能是弥补缺氧时视力下降的一种非侵入性方法。