MODULATION OF PURSUIT EYE-MOVEMENTS BY STIMULATION OF CORTICAL AREAS MT AND MST
MODULATION OF PURSUIT EYE-MOVEMENTS BY STIMULATION OF CORTICAL AREAS MT AND MST
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DOI：
10.1152/jn.1989.62.1.31
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发表时间：
1989-07-01
影响因子：
2.5
通讯作者：
WURTZ, RH
中科院分区：
文献类型：
--
作者：
KOMATSU, H;WURTZ, RH
1.在猴的上级颞沟（STS），代表在追求眼球运动过程中的视野中央凹区放电的许多细胞。当目标朝向有病变的大脑一侧时，这些区域的损伤会导致追踪眼球运动的维持缺陷。在本实验中，我们电刺激这些区域，以更好地定位和理解这种定向追踪缺陷的机制。2.猴子被训练使用步进斜坡任务来追踪移动目标，在该任务中，目标首先步进到偏心位置，然后在屏幕上平滑移动。在猴子开始追逐目标后施加一连串刺激，以研究维持追逐的刺激效果。3.在追逐过程中的刺激经常产生朝向大脑刺激侧的眼球加速度。眼速在向刺激的一侧追踪时增加，在远离刺激的一侧追踪时降低。这种朝向刺激可能激活细胞的大脑一侧的速度增加与通过化学损伤去除细胞后朝向大脑一侧的追踪速度降低一致。4.刺激后追踪速度的增加或减少会使目标在视网膜上滑动。然而，追踪系统似乎对刺激期间的这种滑动不敏感，因为在追踪稳定图像（开环条件）期间的刺激效果类似于在正常追踪条件（闭环）下刺激产生的效果。这种对刺激过程中视觉运动的不敏感性表明刺激替代了视觉输入。5.刺激引起的眼与目标位置的分离确实产生了追赶性眼跳。这为中颞区（MT）和内侧上级颞区（MST）的改变改变视觉运动信息而不是视觉位置信息提供了额外的证据。6.刺激，产生的眼睛加速度在追求过程中只产生轻微的影响，在固定的目标。刺激的有效性也随着追踪速度在5到25度/秒之间的增加而增加。这些观察结果表明，追求速度改变了刺激的效果，表明刺激作用于视觉运动处理之前，有关追求运动本身的信息被纳入。由于这种刺激会产生方向性的追求效果，我们假设追求的方向性偏差起源于传递给追求系统的视觉信号。（400字处截断摘要）
1. Many cells in the superior temporal sulcus (STS) of the monkey that represent the foveal region of the visual field discharge during pursuit eye movements. Damage to these areas produces a deficit in the maintenance of pursuit eye movements when the target towards the side of the brain with the lesion. In the present experiments, we electrically stimulated these areas to better localize and understand the mechanisms underlying this directional pursuit deficit. 2. Monkeys were trained to pursue a moving target using a step-ramp task in which the target first stepped to an eccentric position and then moved smoothly across the screen. Trains of stimulation were applied after the monkey had begun to pursue the target to study stimulation effects of maintenance of pursuit. 3. Stimulation during pursuit frequently produced eye acceleration toward the side of the brain stimulated. Eye speed increased during pursuit toward the side stimulated and decreased during pursuit away from the side stimulated. This increase in velocity toward the side of the brain where stimulation presumably activated cells is consistent with the decrease in pursuit velocity toward the side of the brain after cells were removed by chemical lesions. 4. The increase or decrease in pursuit speed following stimulation produced a slip of the target on the retina. The pursuit system seemed to be insensitive to this slip during the period of stimulation, however, since the effect of stimulation during pursuit of a stabilized image (open-loop condition) was similar to that resulting from stimulation under normal pursuit conditions (closed-loop). This insensitivity to visual motion during stimulation suggests that the stimulation substitutes for that visual input. 5. The separation of eye and target position that resulted from stimulation did produce catch-up saccades. This provides added evidence that alteration of middle temporal area (MT) and medial superior temporal area (MST) modifies visual-motion but not visual-position information. 6. Stimulation that produced eye acceleration during pursuit produced only a slight effect during fixation of a stationary target. The effectiveness of the stimulation also increased as the speed of the pursuit increased between 5 and 25 degrees/s. These observations, which show that pursuit velocity altered the effect of stimulation, suggest that the stimulation acted on visual motion processing before information about the pursuit movement itself is incorporated. Since this stimulation produces directional pursuit effects, we hypothesize that the directional bias for pursuit originates in the visual signal conveyed to the pursuit system.(ABSTRACT TRUNCATED AT 400 WORDS)