What triggers catch-up saccades during visual tracking?
What triggers catch-up saccades during visual tracking?
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DOI：
10.1152/jn.00432.2001
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发表时间：
2002-03-01
影响因子：
2.5
通讯作者：
Lefèvre, P
中科院分区：
文献类型：
--
作者：
de Brouwer, S;Yuksel, D;Lefèvre, P
当追踪移动的视觉刺激时，灵长类动物通过结合两种具有非常不同动力学的眼球运动，平滑追踪和扫视，来定位它们的视轴。然而，控制从一种类型的眼球运动切换到另一种类型的决定的机制仍然知之甚少，即使它们可以为理解CNS如何结合不同类型的控制策略以实现共同的运动和感觉目标做出重大贡献。在这项研究中，我们调查了眼动反应的位置误差和速度误差的大范围不同的组合在视觉跟踪的运动刺激在人类。我们发现，眼动系统使用眼睛轨迹将穿过目标的时间的预测，定义为“眼睛穿过时间”（T-XE）。取决于位置误差和速度误差两者的眼睛交叉时间是用于在平滑追踪和扫视追踪之间切换的标准，即，来触发追赶性眼跳平均而言，对于40和180 ms之间的T-XE，没有扫视被触发，并且目标跟踪保持纯粹平滑。相反，当T-XE变得小于40 ms或大于180 ms时，在短延迟（约125 ms）之后触发扫视。
When tracking moving visual stimuli, primates orient their visual axis by combining two kinds of eye movements, smooth pursuit and saccades, that have very different dynamics. Yet, the mechanisms that govern the decision to switch from one type of eye movement to the other are still poorly understood, even though they could bring a significant contribution to the understanding of how the CNS combines different kinds of control strategies to achieve a common motor and sensory goal. In this study, we investigated the oculomotor responses to a large range of different combinations of position error and velocity error during visual tracking of moving stimuli in humans. We found that the oculomotor system uses a prediction of the time at which the eye trajectory will cross the target, defined as the "eye crossing time" (T-XE). The eye crossing time, which depends on both position error and velocity error, is the criterion used to switch between smooth and saccadic pursuit, i.e., to trigger catch-up saccades. On average, for T-XE between 40 and 180 ms, no saccade is triggered and target tracking remains purely smooth. Conversely, when T-XE becomes smaller than 40 ms or larger than 180 ms, a saccade is triggered after a short latency (around 125 ms).