Tian Jing, Zee David S, Walker Mark F
Department of Neurology, The Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Pathology 2-210, Baltimore, MD, 21287, USA.
Exp Brain Res. 2006 May;171(2):225-30. doi: 10.1007/s00221-005-0261-1. Epub 2005 Nov 24.
The time course of eye-position-dependent torsion during transient horizontal pursuit and yaw rotation was examined in seven normal human subjects. The stimuli consisted of step-ramp target motion (25, 40 degrees /s) and brief chair rotation (approximately 200 degrees /s(2) accelerated to 40 degrees /s) at three different vertical positions (center 0 degrees , up or down 15 degrees ). Three-dimensional eye movements were recorded with dual search coils. The kinematics of pursuit and the rotational vestibulo-ocular reflex (rVOR) were assessed by determining the tilt-angle slope, a measure of the variation of the axis of eye-velocity with vertical eye position. We found that the tilt-angle slope during pursuit was initially 0.4+/-0.07 (mean+/-95% confidence interval) and then gradually rose to 0.64+/-0.04, at about the time that the steady-state eye-velocity was reached. The rVOR began with a nearly head-fixed axis (0.08+/-0.04), appropriate for full retinal image stabilization, followed by a gradual increase of the tilt-angle slope to 0.31+/-0.02. Thus, differences between pursuit and the rVOR with respect to Listing's law can be seen from the onset of transient responses, although in both cases eye-position-dependent torsion increases with time. This temporal evolution of the axis of eye-velocity may involve the velocity-storage mechanism.
在七名正常人类受试者中，研究了瞬态水平追踪和偏航旋转过程中眼位依赖性扭转的时间进程。刺激包括在三个不同垂直位置（中心0度、向上或向下15度）的阶跃斜坡目标运动（25、40度/秒）和短暂的椅子旋转（约200度/秒²加速至40度/秒）。使用双搜索线圈记录三维眼动。通过确定倾斜角斜率来评估追踪和旋转前庭眼反射（rVOR）的运动学，倾斜角斜率是眼速度轴随垂直眼位变化的一种度量。我们发现，追踪过程中的倾斜角斜率最初为0.4±0.07（平均值±95%置信区间），然后在达到稳态眼速度时逐渐上升至0.64±0.04。rVOR开始时轴几乎固定在头部（0.08±0.04），适合完全视网膜图像稳定，随后倾斜角斜率逐渐增加至0.31±0.02。因此，尽管在两种情况下眼位依赖性扭转都随时间增加，但从瞬态反应开始就可以看出追踪和rVOR在利斯廷定律方面的差异。眼速度轴的这种时间演变可能涉及速度存储机制。
