Sackler Faculty of Medicine, Tel Aviv University, Israel.
The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, Israel.
J Neurol Sci. 2022 Oct 15;441:120384. doi: 10.1016/j.jns.2022.120384. Epub 2022 Aug 18.
Optokinetic nystagmus (OKN) was studied in an immersive virtual reality (VR) environment with both typical optokinetic stimulation (OKs) wherein the head-tracking is active (similar to be sitting in front of a rotating drum) or a unique stimulus (VR-OKs) wherein the head-tracking is turned off, so head movements do not update the visual image (which moves with the head).
To study both the perception of the stimulus velocity and eye movements while subjects rotated their head from side to side and the visual scene was either a typical OKs or VR-OKs.
9 healthy participants (aged 23 ± 2.4 y/o) had head and eye movements recorded under typical OKs and VR-OKS while smoothly rotating their head horizontally from side to side. Stimulation was delivered using a virtual reality setup on top of an eye movements recording system.
Under VR-OKs participants perceived faster stimulus velocity when the head and stimulus had the same direction as compared to the head and stimulus in opposite directions. When the head turned in the same direction as the stimulus, there were fewer fast phase eye movements than when it rotated counter to stimulus motion direction. Conversely, with typical OKs, participants perceived faster stimulus velocity when the head and stimulus had opposite directions as compared to the head and stimulus having the same direction.
The seemingly paradoxical results in which slower stimulus velocity is perceived in tandem with stronger nystagmus can be explained by the simultaneous activation of the Vestibulo-Ocular Reflex and OKN in accordance with the various visual and vestibular stimuli.
在沉浸式虚拟现实 (VR) 环境中研究了视动性眼球震颤 (OKN)，其中包括典型的视动刺激 (OKs)，其中头部跟踪是活跃的（类似于坐在旋转鼓前）或独特的刺激（VR-OKs），其中头部跟踪关闭，因此头部运动不会更新视觉图像（随头部移动）。
研究当受试者左右旋转头部时，对刺激速度的感知和眼球运动，同时视觉场景是典型的 OKs 还是 VR-OKs。
9 名健康受试者（年龄 23±2.4 岁）在典型 OKs 和 VR-OKs 下记录头部和眼部运动，同时水平平稳地左右旋转头部。刺激是通过在眼球运动记录系统顶部的虚拟现实设置来提供的。
在 VR-OKs 下，当头部和刺激具有相同方向时，参与者感知到的刺激速度比头部和刺激相反方向时更快。当头与刺激同向转动时，快相眼动的次数比头与刺激反向转动时少。相反，在典型的 OKs 下，当头部和刺激具有相反方向时，参与者感知到的刺激速度比头部和刺激具有相同方向时更快。
当刺激速度较慢时，可以通过同时激活前庭眼反射和视动性眼球震颤来解释与较强的眼球震颤相伴随的看似矛盾的结果，这与各种视觉和前庭刺激有关。
