Optokinetic eye movements elicited by radial optic flow in the macaque monkey
Optokinetic eye movements elicited by radial optic flow in the macaque monkey
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DOI：
10.1152/jn.1998.79.3.1461
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发表时间：
1998-03-01
影响因子：
2.5
通讯作者：
Hoffmann, KP
中科院分区：
文献类型：
--
作者：
Lappe, M;Pekel, M;Hoffmann, KP
我们用巩膜搜索线圈技术记录了径向光流引起的三只猕猴的自发眼动。计算机生成的刺激模拟了猴子的向前或向后运动，这些运动与虚拟地平面上排列的一些小照明点有关。我们想了解光动眼动是否由模拟自我运动的径向视神经刺激引起，量化它们的参数，并考虑它们对视神经加工的影响。观察到快速和慢速眼球运动以2赫兹的频率交换的规律模式。当我们在模拟向前运动（扩展光流）过程中移动扩展焦点（FOE）的水平位置时，眼的中间水平位置也发生了相同方向的移动，但移动的幅度较小；对于模拟向后运动（收缩光流），眼正中位置向相反方向移动。我们将此与Schlagfeld的变化联系起来，这种变化通常是在光动性眼球震颤中观察到的。将慢相眼球运动的方向和速度与注视方向（中央凹方向）的局部流场运动进行比较。眼球运动方向与中央凹运动吻合良好。小的系统偏差可归因于全球运动模式的整合。平均眼速与中央凹刺激速度不匹配，因为中位数增益仅与0.5-0.6相似。扩张刺激的收益总是低于收缩刺激的收益。我们分析了每次扫视后眼球运动的时间过程。我们发现在扩张和收缩的初始增益发育和定向跟随方面存在显著差异。对于扩张，方向跟随和增益最初很差，并且在扫视前受到持续的眼动的强烈影响。收缩的情况并非如此。这些差异也可以与光动力学系统的特性联系起来。我们得出的结论是，光动力眼运动可以由模拟自我运动的径向光流场引起。这些眼球运动与中央凹旁流场有关，即注视方向的运动。在视光流的视网膜投影中，这种眼球运动叠加了视网膜滑动。这导致了复杂的视网膜运动模式，特别是因为眼球运动的增益是小而可变的。这一观察结果与决定视网膜流场自我运动的机制特别相关。在光流分析中有必要考虑眼球运动的影响，但我们的研究结果表明，眼球运动的方向和速度应该区别对待。
We recorded spontaneous eye movements elicited by radial optic flow in three macaque monkeys using the scleral search coil technique. Computer-generated stimuli simulated forward or backward motion of the monkey with respect to a number of small illuminated dots arranged on a virtual ground plane. We wanted to see whether optokinetic eye movements are induced by radial optic how stimuli that simulate self-movement, quantify their parameters, and consider their effects on the processing of optic how. A regular pattern of interchanging fast and slow eye movements with a frequency of 2 Hz was observed. When we shifted the horizontal position of the focus of expansion (FOE) during simulated forward motion (expansional optic flow), median horizontal eye position also shifted in the same direction but only by a smaller amount; for simulated backward motion( contractional optic flow), median eye position shifted in the opposite direction. We relate this to a change in Schlagfeld typically observed in optokinetic nystagmus. Direction and speed of slow phase eye movements were compared with the local flow field motion in gaze direction (the foveal how). Eye movement direction matched well the foveal motion. Small systematic deviations could be attributed to an integration of the global motion pattern. Eye speed on average did not match foveal stimulus speed, as the median gain was only similar to 0.5-0.6. The gain was always lower for expanding than for contracting stimuli. We analyzed the time course of the eye movement immediately after each saccade. We found remarkable differences in the initial development of gain and directional following for expansion and contraction. For expansion, directional following and gain were initially poor and strongly influenced by the ongoing eye movement before the saccade. This was not the case for contraction. These differences also can be linked to properties of the optokinetic system. We conclude that optokinetic eye movements can be elicited by radial optic flow fields simulating self-motion. These eye movements are linked to the parafoveal flow field, i.e., the motion in the direction of gaze. In the retinal projection of the optic flow, such eye movements superimpose retinal slip. This results in complex retinal motion patterns, especially because the gain of the eye movement is small and variable. This observation has special relevance for mechanisms that determine self-motion from retinal flow fields. It is necessary to consider the influence of eye movements in optic flow analysis, but our results suggest that direction and speed of an eye movement should be treated differently.