Neurology Department, Zurich University Hospital, Frauenklinikstrasse 26, CH-8091 Zurich, Switzerland.
J Neurophysiol. 2011 Jan;105(1):209-23. doi: 10.1152/jn.00154.2010. Epub 2010 Nov 10.
Self-motion perception after a sudden stop from a sustained rotation in darkness lasts approximately as long as reflexive eye movements. We hypothesized that, after an angular velocity step, self-motion perception and reflexive eye movements are driven by the same vestibular pathways. In 16 healthy subjects (25-71 years of age), perceived rotational velocity (PRV) and the vestibulo-ocular reflex (rVOR) after sudden decelerations (90°/s(2)) from constant-velocity (90°/s) earth-vertical axis rotations were simultaneously measured (PRV reported by hand-lever turning; rVOR recorded by search coils). Subjects were upright (yaw) or 90° left-ear-down (pitch). After both yaw and pitch decelerations, PRV rose rapidly and showed a plateau before decaying. In contrast, slow-phase eye velocity (SPV) decayed immediately after the initial increase. SPV and PRV were fitted with the sum of two exponentials: one time constant accounting for the semicircular canal (SCC) dynamics and one time constant accounting for a central process, known as velocity storage mechanism (VSM). Parameters were constrained by requiring equal SCC time constant and VSM time constant for SPV and PRV. The gains weighting the two exponential functions were free to change. SPV were accurately fitted (variance-accounted-for: 0.85 ± 0.10) and PRV (variance-accounted-for: 0.86 ± 0.07), showing that SPV and PRV curve differences can be explained by a greater relative weight of VSM in PRV compared with SPV (twofold for yaw, threefold for pitch). These results support our hypothesis that self-motion perception after angular velocity steps is be driven by the same central vestibular processes as reflexive eye movements and that no additional mechanisms are required to explain the perceptual dynamics.
在黑暗中从持续旋转突然停止后，自身运动感知持续的时间大约与反射性眼球运动相同。我们假设，在角速度阶跃后，自身运动感知和反射性眼球运动由相同的前庭途径驱动。在 16 名健康受试者（25-71 岁）中，同时测量了从恒定速度（90°/s）地球垂直轴旋转突然减速（90°/s²）后的感知旋转速度（PRV）和前庭眼反射（rVOR）（通过手动操纵杆报告 PRV；通过搜索线圈记录 rVOR）。受试者处于直立（偏航）或左耳向下 90°（俯仰）。在偏航和俯仰减速后，PRV 迅速升高并在衰减前达到平台。相比之下，慢相眼速度（SPV）在初始增加后立即衰减。SPV 和 PRV 拟合为两个指数的和：一个时间常数用于解释半规管（SCC）动力学，一个时间常数用于解释中央过程，称为速度存储机制（VSM）。通过要求 SPV 和 PRV 的 SCC 时间常数和 VSM 时间常数相等来约束参数。两个指数函数的增益可以自由变化。SPV 被准确拟合（方差解释：0.85 ± 0.10）和 PRV（方差解释：0.86 ± 0.07），表明 SPV 和 PRV 曲线差异可以通过 PRV 中 VSM 的相对权重大于 SPV 来解释（偏航时为两倍，俯仰时为三倍）。这些结果支持我们的假设，即角速度阶跃后自身运动感知是由与反射性眼球运动相同的中央前庭过程驱动的，并且不需要额外的机制来解释感知动力学。
