Modeling control of eye orientation in three dimensions. I. Role of muscle pulleys in determining saccadic trajectory
Modeling control of eye orientation in three dimensions. I. Role of muscle pulleys in determining saccadic trajectory
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DOI：
10.1152/jn.1998.79.5.2653
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发表时间：
1998-05-01
影响因子：
2.5
通讯作者：
Raphan, T
中科院分区：
文献类型：
--
作者：
Raphan, T
本研究评估了肌肉轴位移对中枢神经系统矢量速度位置积分器性能的影响。早期的动眼植物模型假设，当眼睛旋转到第二眼和第三眼位置时，肌肉轴相对于头部保持固定。在此假设下，当眼睛从第二级注视位置移动到第三级注视位置时，矢量积分器模型会生成扭转瞬态。扭转瞬态表示对保持固定在头部中的扭矩轴与变化了眼睛定向变化的角度一半的位移平面之间的空间不匹配的眼睛运动响应。当将肌肉轴移动纳入模型时，整个轨迹中每个眼睛方向的扭矩轴都更接近位移平面，并且扭转瞬态显着减少。它们的大小和动态与报道的数据接近。研究还表明，当肌肉扭矩轴旋转眼球旋转 50% 时，不存在扭转瞬态，并且完全遵循 Listing 定律。当肌肉扭矩轴旋转 > 50% 时，扭转瞬变方向与肌肉轴偏移发生的情况相反。
This study evaluates the effects of muscle axis shifts on the performance of a vector velocity-position integrator in the CNS. Earlier models of the oculomotor plant assumed that the muscle axes remained fixed relative to the head as the eye rotated into secondary and tertiary eye positions. Under this assumption, the vector integrator model generates torsional transients as the eye moves from secondary to tertiary positions of fixation. The torsional transient represents an eye movement response to a spatial mismatch between the torque axes that remain fixed in the head and the displacement plane that changes by half the angle of the change in eye orientation. When muscle axis shifts were incorporated into the model, the torque axes were closer to the displacement plane at each eye orientation throughout the trajectory, and torsional transients were reduced dramatically. Their size and dynamics were close to reported data. It was also shown that when the muscle torque axes were rotated by 50% of the eye rotation, there was no torsional transient and Listing's law was perfectly obeyed. When muscle torque axes rotated >50%, torsional transients reversed direction compared with what occurred for muscle axis shifts of