Target acceleration can be extracted and represented within the predictive drive to ocular pursuit
Target acceleration can be extracted and represented within the predictive drive to ocular pursuit
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DOI：
10.1152/jn.00132.2007
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发表时间：
2007-09-01
影响因子：
2.5
通讯作者：
Lefevre, Philippe
中科院分区：
文献类型：
--
作者：
Bennett, Simon J.;de Xivry, Jean-Jacques Orban;Lefevre, Philippe
在充分暴露于刺激呈现的情况下，眼动系统生成刺激特征的表示，然后使用该表示来预测即将到来的目标运动。除了补偿知觉-运动延迟外，这些预测过程还会在短暂遮挡期间保持眼球运动，并补偿视觉输入的损失。然而，目前还不清楚眼动系统是否以及如何提取和表示后续预测控制的目标加速度。为此，我们使用了目标遮挡范式，在遮挡过程中和目标再现时，如果不在目标消失之前提取目标加速度，则无法预测目标的位置和速度。我们发现，当初始曝光为200ms时，消隐期间的动眼反应不受目标加速度的影响。然而，在最初的500毫秒或800毫秒的曝光后，流畅的眼球运动和跳动的眼球运动确实区分了不同水平的加速。在咬合过程中的平滑反应与目标轨迹不匹配的情况下，因此消除了发展中的位移误差，存在增加的扫视位移。尽管如此，在消失期的综合反应并没有消除目标再现时的视网膜滑移和位置误差。这些结果表明，在追逐可见坡道的过程中，可以在线提取关于目标加速的信息，然后在没有视觉输入的情况下使用该信息来驱动预测性眼动反应。
Given sufficient exposure to stimulus presentation, the oculomotor system generates a representation of the stimulus characteristics, which is then used to predict the upcoming target motion. In addition to compensating for the perceptual-motor delay, these predictive processes perpetuate eye motion during a transient occlusion and compensate for the loss of visual input. At present, however, it is not well understood whether and how the oculomotor system extracts and represents target acceleration for subsequent predictive control. To this end, we used a target occlusion paradigm where both position and velocity of the target during the occlusion and at reappearance could not be predicted without extracting target acceleration before target disappearance. We found that the oculomotor response during the blanking period was not influenced by target acceleration when the initial exposure was 200 ms. However, smooth and saccadic eye movements did discriminate between the different levels of acceleration after an initial 500-or 800-ms exposure. In the event that the smooth response during the occlusion did not match well the target trajectory and thus eliminate a developing displacement error, there was an increased saccadic displacement. Still, the combined response during the blanking period did not eliminate retinal slip and position error at target reappearance. These results indicate that information on target acceleration can be extracted on-line, during pursuit of a visible ramp, and then used to drive a predictive oculomotor response in the absence of visual input.