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Invest Ophthalmol Vis Sci. 2020 May 11;61(5):4. doi: 10.1167/iovs.61.5.4.
Acceleration plays a great impact on the vestibular system, but is attributed little influence over vision. This study aims to explore how visual and vestibular acceleration affect roll-plane oculomotor responses, including their addiative effect.
Seated in a mechanical sled, 13 healthy volunteers (7 men, 6 women; mean age 25 years) were exposed to a series of visual (VIS) optokinetic, vestibular (VES) whole-body, and combined (VIS + VES) rotations. This was carried out at two acceleration intensities. Subjects wore a video-based eye tracker, enabling analysis of torsional and skewing eye movement responses, which were used to evaluate the individual response to each trial. The tracker also contained accelerometers allowing head tracking.
Both ocular torsion and vertical skewing were sensitive to acceleration intensities for VES and VIS + VES. For VIS only, skewing exhibited such a response. An increased acceleration yielded a decreased torsion-skewing ratio for VIS, explained by the change in skewing, but remained unchanged for VES and VIS + VES. Torsion exhibited particularly reliable summative effect, yielding a relative contribution of 32% VIS and 75% VES during low acceleration, and 19% and 85%, respectively, during high acceleration.
The change in the skewing response to different intensities indicates that the visual system is more sensitive to visual accelerations than previously described. Eye movements showed reliable summative effects, indicating a robust visual-vestibular integration that indicates their integrative priorities for each acceleration, with the visual system being more involved during low accelerations. Such objective quantifications could hold clinical utility when assessing sensory mismatch in vertiginous patients.
加速度对前庭系统有很大的影响,但对视觉的影响很小。本研究旨在探讨视觉和前庭加速度如何影响滚转平面眼球运动反应,包括它们的相加效应。
13 名健康志愿者(7 名男性,6 名女性;平均年龄 25 岁)坐在机械雪橇上,分别接受一系列视觉(VIS)视动、前庭(VES)全身和联合(VIS+VES)旋转刺激。这是在两种加速度强度下进行的。受试者佩戴基于视频的眼动追踪器,能够分析扭转和偏斜眼球运动反应,用于评估每个试验的个体反应。跟踪器还包含加速度计,允许头部跟踪。
VES 和 VIS+VES 的眼球扭转和垂直偏斜都对加速度强度敏感。对于 VIS 仅偏斜表现出这样的反应。增加加速度会降低 VIS 的扭转-偏斜比,这是由偏斜的变化引起的,但对于 VES 和 VIS+VES 则保持不变。扭转表现出特别可靠的叠加效应,在低加速度下产生 32% VIS 和 75% VES 的相对贡献,在高加速度下分别产生 19%和 85%的贡献。
不同强度下偏斜反应的变化表明,视觉系统对视觉加速度比以前描述的更敏感。眼球运动表现出可靠的叠加效应,表明视觉-前庭整合稳健,表明它们对每种加速度的整合优先级,在低加速度下,视觉系统参与更多。当评估眩晕患者的感觉不匹配时,这种客观的量化可能具有临床实用性。