Saccade-vergence interactions in macaques. II. Vergence enhancement as the product of a local feedback vergence motor error and a weighted saccadic burst
Saccade-vergence interactions in macaques. II. Vergence enhancement as the product of a local feedback vergence motor error and a weighted saccadic burst
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DOI：
10.1152/jn.01337.2004
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发表时间：
2005-10-01
影响因子：
2.5
通讯作者：
Mays, LE
中科院分区：
文献类型：
--
作者：
Busettini, C;Mays, LE
在随附的论文中，我们报告说，在组合扫视聚散眼球运动过程中的内扫视聚散增强反映了扫视动力学，这意味着扫视突发信号的参与。这种参与是没有预测的Zee等人的乘法模型。我们提出了一个模型，其中的聚散增强是一个加权的扫视突发信号和非视觉的短潜伏期估计的聚散运动误差在扫视的时间之间的乘法相互作用的结果。由扫视引起的聚散速度的增强使得聚散目标比没有扫视发生时更快地接近。后扫视的聚散速度的调整，以这种更快的减少聚散运动误差发生的时间过程太快的视觉反馈。这意味着存在的内部估计的运动的进展，并表明，聚散度反应的控制下的局部反馈机制。这还意味着，聚散度增强信号被包括在聚散度反馈回路中，并且是聚散度速度命令的组成部分。我们的乘法模型能够预测的峰值速度的聚散度增强作为一个功能的回旋扫视动力学，平滑的聚散度动力学，和扫视-聚散时间具有显着的精度。它同样表现良好的水平和垂直扫视非常相似的参数，这表明一个共同的机制，所有扫视方向。还提出了一种扫视-聚散加性模型，尽管它需要外部开关元件。可能的神经实现进行了讨论。
In the accompanying paper we reported that intrasaccadic vergence enhancement during combined saccade vergence eye movements reflects saccadic dynamics, which implies the involvement of saccadic burst signals. This involvement was not predicted by the Multiply Model of Zee et al. We propose a model wherein vergence enhancement is the result of a multiplicative interaction between a weighted saccadic burst signal and a nonvisual short- latency estimate of the vergence motor error at the time of the saccade. The enhancement of vergence velocity by saccades causes the vergence goal to be approached more rapidly than if no saccade had occurred. The adjustment of the postsaccadic vergence velocity to this faster reduction in vergence motor error occurred with a time course too fast for visual feedback. This implies the presence of an internal estimate of the progress of the movement and indicates that vergence responses are under the control of a local feedback mechanism. It also implies that the vergence enhancement signal is included in the vergence feedback loop and is an integral part of the vergence velocity command. Our multiplicative model is able to predict the peak velocity of the vergence enhancement as a function of cyclopean saccadic dynamics, smooth vergence dynamics, and saccade - vergence timing with remarkable precision. It performed equally well for both horizontal and vertical saccades with very similar parameters, suggesting a common mechanism for all saccadic directions. A saccade - vergence additive model is also presented, although it would require external switching elements. Possible neural implementations are discussed.