Different time scales of motion integration for anticipatory smooth pursuit and perceptual adaptation.
Different time scales of motion integration for anticipatory smooth pursuit and perceptual adaptation.
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DOI：
10.1167/15.2.16
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发表时间：
2015-02
影响因子：
1.8
通讯作者：
Gerrit W. Maus;E. Potapchuk;S. Watamaniuk;S. Heinen
中科院分区：
文献类型：
--
作者：
Gerrit W. Maus;E. Potapchuk;S. Watamaniuk;S. Heinen
当反复暴露于运动刺激时，眼神经系统甚至在刺激移动之前就激发预期平滑追踪（ASP）眼动。ASP的影响与重复运动刺激的感知速度判断相反：在一系列快速刺激后，ASP速度增加，而感知速度降低。这两种效果-感知适应和眼刺激-可能是由于适应一个单一的共同内部速度表示，用于感知比较和生成ASP。在这里，我们测试这一假设，通过评估刺激历史的时间依赖性的影响。观察者进行速度歧视移动随机点刺激，无论是追求运动或保持稳定的固定。在这两种情况下，反应表现出知觉适应：刺激之前的快速被认为是较慢的，反之亦然。为了评估眼刺激启动，我们分析了ASP速度作为平均刺激速度在以前的试验中的函数，发现了很强的正相关性。有趣的是，最大的启动发生在短刺激历史（102次试验），而适应是最大的较长的历史（1015次试验）。适应和启动的时间分离表明了不同的潜在机制。可能的是，感知适应在相对长的时间段上进行整合，以鲁棒地校准运动系统的操作范围，从而避免来自刺激速度的瞬时变化的干扰。另一方面，视觉系统可以快速地启动预期速度，以有效地将其与追击目标的速度相匹配。
When repeatedly exposed to moving stimuli, the oculomotor system elicits anticipatory smooth pursuit (ASP) eye movements, even before the stimulus moves. ASP is affected oppositely to perceptual speed judgments of repetitive moving stimuli: After a sequence of fast stimuli, ASP velocity increases, whereas perceived speed decreases. These two effects--perceptual adaptation and oculomotor priming--could result from adapting a single common internal speed representation that is used for perceptual comparisons and for generating ASP. Here we test this hypothesis by assessing the temporal dependence of both effects on stimulus history. Observers performed speed discriminations on moving random dot stimuli, either while pursuing the movement or maintaining steady fixation. In both cases, responses showed perceptual adaptation: Stimuli preceded by fast speeds were perceived as slower, and vice versa. To evaluate oculomotor priming, we analyzed ASP velocity as a function of average stimulus speed in preceding trials and found strong positive dependencies. Interestingly, maximal priming occurred over short stimulus histories (∼two trials), whereas adaptation was maximal over longer histories (∼15 trials). The temporal dissociation of adaptation and priming suggests different underlying mechanisms. It may be that perceptual adaptation integrates over a relatively long period to robustly calibrate the operating range of the motion system, thereby avoiding interference from transient changes in stimulus speed. On the other hand, the oculomotor system may rapidly prime anticipatory velocity to efficiently match it to that of the pursuit target.