Warfighter Protection Group, U.S. Army Aeromedical Research Laboratory, Fort Novosel, AL 63660, USA.
Oak Ridge Institute for Scientific Research, Fort Novosel, AL 63660, USA.
Mil Med. 2024 Aug 19;189(Suppl 3):751-758. doi: 10.1093/milmed/usae256.
Vection is a stationary individual's illusory experience of self-motion. This illusory self-motion is operationally important for aviation, particularly military aviation, since vection is a dramatic example of spatial disorientation (SD), which is an individual's failure to correctly sense the aircraft's position, motion, and/or attitude with respect to the fixed coordinate system of the Earth's surface and its gravitational vertical. Notably, SD is a major cause of fatal aviation mishaps, and the visual system is particularly prone to provoking vection. This article describes the Virtual Reality Vection System (VRVS), which uses computer-controlled virtual reality technology to induce vection under controlled conditions for training, demonstration, testing, and research.
The VRVS enables the precise specification of the number and appearance of visual stimulus elements intended to generate vection, including photorealistic images. The VRVS can present visual stimuli on any OpenXR-capable virtual reality headset. The VRVS currently records 2 types of behavioral responses, button presses to indicate the presence and duration of vection and the voltage of a handheld linear potentiometer to indicate the presence, duration, and magnitude of vection.
An approved test plan helped guide, organize, document, and validate the VRVS during its development. Under this plan, a pair of tests guided hardware and software development of the VRVS system. Although the first test verified the ability of the VRVS to generate and measure vection, it also demonstrated that the VRVS can quickly manipulate the visual stimuli from one trial to the next so that the VRVS can support complex experimental designs. The second test used these capabilities to verify that the VRVS can characterize vection in a more analytic fashion using a masking paradigm. Specifically, the test assessed whether random stimulus elements injected into the vection-inducing stimulus disrupted vection in a quantifiable fashion. This work opens the door to studies that characterize the necessary and sufficient visual elements for vection-based SD.
The VRVS is currently used to research, develop, test, and evaluate mitigation strategies targeting vection-related SD in degraded visual environments. Similarly, the VRVS is supporting research to develop methods to predict individual differences in visually induced motion sickness susceptibilities. The VRVS is currently being integrated with a precision motor-controlled rotating Barany chair for multisensory studies. It should be noted that since the VRVS was developed to support United States Army Aeromedical Research Laboratory projects, it is an Army product representing government intellectual property and may be freely available to other government institutions.
视动是一种个体在静止状态下产生的运动错觉。这种错觉运动对于航空，特别是军事航空来说具有重要的实际意义，因为视动是空间定向障碍（SD）的一个显著例子，即个体无法正确感知飞机相对于地球表面及其重力垂直的位置、运动和/或姿态。值得注意的是，SD 是致命航空事故的主要原因，而视觉系统特别容易引发视动。本文描述了虚拟现实视动系统（VRVS），该系统使用计算机控制的虚拟现实技术在受控条件下产生视动，用于培训、演示、测试和研究。
VRVS 可以精确指定产生视动的视觉刺激元素的数量和外观，包括逼真的图像。VRVS 可以在任何支持 OpenXR 的虚拟现实耳机上呈现视觉刺激。VRVS 当前记录 2 种行为反应，按下按钮表示视动的存在和持续时间，以及手持线性电位计的电压表示视动的存在、持续时间和幅度。
经批准的测试计划有助于指导、组织、记录和验证 VRVS 的开发过程。根据该计划，一对测试指导了 VRVS 系统的硬件和软件开发。虽然第一次测试验证了 VRVS 产生和测量视动的能力，但它也表明 VRVS 可以快速在一次试验到下一次试验之间操作视觉刺激，从而使 VRVS 能够支持复杂的实验设计。第二次测试使用这些功能通过掩蔽范式验证了 VRVS 可以更具分析性地描述视动。具体来说，该测试评估了随机注入视动诱导刺激中的刺激元素是否以可量化的方式破坏视动。这项工作为研究基于视动的 SD 所需和充分的视觉元素打开了大门。
VRVS 目前用于研究、开发、测试和评估针对视动相关 SD 的降级视觉环境中的缓解策略。同样，VRVS 也支持开发预测个体在视觉诱导运动病易感性方面差异的方法。VRVS 目前正在与精密电机控制的旋转 Barany 椅集成，用于多感觉研究。需要指出的是，由于 VRVS 是为支持美国陆军航空医学研究实验室的项目而开发的，因此它是一种代表政府知识产权的陆军产品，可能可供其他政府机构自由使用。
