Schiller P H, Sandell J H
Exp Brain Res. 1983;49(3):381-92. doi: 10.1007/BF00238780.
Recent work has shown that humans and monkeys utilize both retinal error and eye position signals to compute the direction and amplitude of saccadic eye movements (Hallett and Lightstone 1976a, b; Mays and Sparks 1980b). The aim of this study was to examine the role the frontal eye fields (FEF) and the superior colliculi (SC) play in this computation. Rhesus monkeys were trained to acquire small, briefly flashed spots of light with saccadic eye movements. During the latency period between target extinction and saccade initiation, their eyes were displaced, in total darkness, by electrical stimulation of either the FEF, the SC or the abducens nucleus area. Under such conditions animals compensated for the electrically induced ocular displacement and correctly reached the visual target area, suggesting that both a retinal error and eye position error signal were computed. The amplitude and direction of the electrically induced saccades depended not only on the site stimulated but also on the amplitude and direction of the eye movement initiated by the animal to acquire the target. When the eye movements initiated by the animal coincided with the saccades initiated by electrical stimulation, the resultant saccade was the weighted average of the two, where one weighing factor was the intensity of the electrical stimulus. Animals did not acquire targets correctly when their eyes were displaced, prior to their intended eye movements, by stimulating in the abducens nucleus area. After bilateral ablation of either the FEF or the SC monkeys were still able to acquire visual targets when their eyes were displaced, prior to saccade initiation, by electrical stimulation of the remaining intact structure. These results suggest that neither the FEF nor the SC is uniquely responsible for the combined computation of the retinal error and the eye position error signals.
最近的研究表明，人类和猴子利用视网膜误差和眼位信号来计算眼球快速运动的方向和幅度（哈雷特和莱特斯通，1976a，b；梅斯和斯帕克斯，1980b）。本研究的目的是检验额叶眼区（FEF）和上丘（SC）在这种计算中所起的作用。恒河猴经过训练，能用眼球快速运动来获取小的、短暂闪烁的光点。在目标消失到扫视开始的潜伏期内，通过电刺激FEF、SC或展神经核区域，在完全黑暗的环境中使它们的眼睛发生位移。在这种情况下，动物能够补偿电诱导的眼位移，并正确地到达视觉目标区域，这表明视网膜误差和眼位误差信号都得到了计算。电诱导扫视的幅度和方向不仅取决于刺激部位，还取决于动物为获取目标而发起的眼动的幅度和方向。当动物发起的眼动与电刺激引发的扫视一致时，合成的扫视是两者的加权平均值，其中一个加权因子是电刺激的强度。当通过刺激展神经核区域在动物预期的眼动之前使它们的眼睛发生位移时，动物不能正确获取目标。在双侧切除FEF或SC后，当在扫视开始前通过电刺激剩余的完整结构使它们的眼睛发生位移时，猴子仍然能够获取视觉目标。这些结果表明，FEF和SC都不是唯一负责视网膜误差和眼位误差信号联合计算的结构。
