Properties of signals that determine the amplitude and direction of saccadic eye movements in monkeys.
Properties of signals that determine the amplitude and direction of saccadic eye movements in monkeys.
复制标题
决定猴子眼球扫视运动幅度和方向的信号特性。
DOI：
10.1152/jn.1986.56.1.196
复制
发表时间：
1986
影响因子：
2.5
通讯作者：
Lisberger,SG
中科院分区：
文献类型：
--
作者：
McKenzie,A;Lisberger,SG
猴子被训练对短暂闪现的目标进行扫视。我们在平滑地追逐另一个目标的过程中呈现闪光，这样在闪光之后眼睛的位置会有一个平滑的变化。然后，我们可以确定闪光灯引发的扫视是否补偿了中间平滑的眼球运动，使眼睛指向空间中闪光的位置。我们将“视网膜误差”定义为从眼睛在闪烁时的位置到目标位置的矢量。我们将“空间误差”定义为从眼睛在扫视时的位置到闪烁目标在空间中的位置的矢量。扫视的方向（极坐标）与视网膜误差的方向的相关性比与空间误差的方向的相关性更强。眼跳振幅与视网膜误差振幅也有较好的相关性。无论是在头部固定的追逐过程中，还是在眼球联合运动的追逐过程中，我们都得到了相同的结果。统计分析表明，三只猴子中有两只的扫视方向仅由视网膜误差决定。在第三个实验中，猴子的眼跳方向主要由视网膜误差决定，但始终偏向于空间误差。这种偏差可以归因于这只猴子早期的练习，在这个练习中，闪烁的目标被重新照亮，这样它就可以最终扫视到空间中的正确位置。这些数据表明，眼跳产生器通常不使用关于眼睛或凝视位置的平滑变化的非视觉反馈。在两只猴子身上，我们也在追逐过程中提供了连续的目标闪光，第二次闪光的时间设定在第一次扫视之前。如上所述，第一次扫视适合于第一次闪光所提供的视网膜误差。第二次扫视是对第一次扫视的补偿，将眼睛对准了第二个目标在空间中的位置。我们得出结论，正如其他人之前（12,21），眼跳生成器接收到关于其自身输出的反馈，眼跳。我们的结果需要对产生扫视的神经网络的现有模型进行修正。我们提出了两种模型，保留了其他人建议的内部反馈的使用。我们倾向于一个模型，该模型假设内部反馈直接来自于眼跳生成器的输出，并且只报告眼睛位置的眼跳变化。
Monkeys were trained to make saccades to briefly flashed targets. We presented the flash during smooth pursuit of another target, so that there was a smooth change in eye position after the flash. We could then determine whether the flash-evoked saccades compensated for the intervening smooth eye movements to point the eyes at the position of the flash in space. We defined the "retinal error" as the vector from the position of the eye at the time of the flash to the position of the target. We defined "spatial error" as the vector from the position of the eye at the time of the saccade to the position of the flashed target in space. The direction of the saccade (in polar coordinates) was more highly correlated with the direction of the retinal error than with the direction of the spatial error. Saccade amplitude was also better correlated with the amplitude of the retinal error. We obtained the same results whether the flash was presented during pursuit with the head fixed or during pursuit with combined eye-head movements. Statistical analysis demonstrated that the direction of the saccade was determined only by the retinal error in two of the three monkeys. In the third monkey saccade direction was determined primarily by retinal error but had a consistent bias toward spatial error. The bias can be attributed to this monkey's earlier practice in which the flashed target was reilluminated so he could ultimately make a saccade to the correct position in space. These data suggest that the saccade generator does not normally use nonvisual feedback about smooth changes in eye or gaze position. In two monkeys we also provided sequential target flashes during pursuit with the second flash timed so that it occurred just before the first saccade. As above, the first saccade was appropriate for the retinal error provided by the first flash. The second saccade compensated for the first and pointed the eyes at the position of the second target in space. We conclude, as others have before (12, 21), that the saccade generator receives feedback about its own output, saccades. Our results require revision of existing models of the neural network that generates saccades. We suggest two models that retain the use of internal feedback suggested by others. We favor a model that accounts for our data by assuming that internal feedback originates directly from the output of the saccade generator and reports only saccadic changes in eye position.