Merfeld D M, Young L R, Tomko D L, Paige G D
Man-Vehicle Laboratory, Massachusetts Institute of Technology, Cambridge.
Acta Otolaryngol Suppl. 1991;481:287-92. doi: 10.3109/00016489109131403.
The interaction of angular and linear stimuli produces a complex alignment of spatial orientation and the VOR. This phenomenon was studied by measuring three dimensional eye movements in 6 squirrel monkeys during centrifugation in the dark. The axis of eye rotation was always aligned with gravity and with the spinal axis of the upright monkeys. The erect monkeys were oriented such that they were either facing toward the direction of motion or were facing away from the motion. Angular velocity trapezoids were utilized as the motion stimuli with a ramp acceleration of 10 degrees/s2 to a constant velocity of 200 degrees/s. This yields a final centripetal acceleration of 1 g. The orientation of centripetal acceleration dramatically altered the VOR by changing the axis of eye rotation, the peak value of slow phase eye velocity, and the time constant of per-rotary decay. The axis of eye rotation always tended to align with gravito-inertial force, the peak value of slow phase eye velocity was greater when the monkey faced the motion than when it faced away from the motion, and the time constant of decay was smaller when the monkey faced the motion than when it faced away from the motion. These findings were statistically significant (p less than 0.05) and were consistent across all monkeys. The data also indicate that the VOR may be separated into two reflexes, a linear reflex and a rotational reflex. The linear reflex decays as the axis of eye rotation aligns with gravito-inertial force (GIF). These results indicate that GIF is resolved into two components: one representing an internal estimate of linear acceleration and one representing an internal estimate of gravity.
角向刺激和线性刺激的相互作用产生了空间定向和前庭眼反射（VOR）的复杂对齐。通过在黑暗中对6只松鼠猴进行离心时测量三维眼球运动，对这一现象进行了研究。眼球旋转轴始终与重力以及直立猴子的脊柱轴对齐。直立的猴子的朝向使得它们要么面向运动方向，要么背向运动方向。角速度梯形被用作运动刺激，斜坡加速度为10度/秒²，恒定速度为200度/秒。这产生了最终向心加速度为1g。向心加速度的方向通过改变眼球旋转轴、慢相眼球速度的峰值以及每次旋转衰减的时间常数，显著改变了前庭眼反射。眼球旋转轴总是倾向于与重力惯性力对齐，当猴子面向运动时慢相眼球速度的峰值大于背向运动时，并且当猴子面向运动时衰减的时间常数小于背向运动时。这些发现具有统计学意义（p小于0.05），并且在所有猴子中都是一致的。数据还表明，前庭眼反射可能分为两种反射，一种是线性反射，一种是旋转反射。随着眼球旋转轴与重力惯性力（GIF）对齐，线性反射衰减。这些结果表明，重力惯性力被分解为两个分量：一个代表线性加速度的内部估计，一个代表重力的内部估计。
