Vercher J L, Quaccia D, Gauthier G M
Laboratoire de Contrôles Sensorimoteurs, Université de Provence, Marseille, France.
Exp Brain Res. 1995;103(2):311-22. doi: 10.1007/BF00231717.
We evaluated the role of visual and non-visual information in the control of smooth pursuit movements during tracking of a self-moved target. Previous works have shown that self-moved target tracking is characterised by shorter smooth pursuit latency and higher maximal velocity than eye-alone tracking. In fact, when a subject tracks a visual target controlled by his own arm, eye movement and arm movement are closely synchronised. In the present study, we showed that, in a condition where the direction of motion of a self-moved visual target was opposite to that of the arm (same amplitude, same velocity, but opposite direction of movement), the resulting smooth pursuit eye movements occurred with low latency, and continued for about 140 ms in the direction of the arm movement rather than in the direction of the actual visual target movement. After 140 ms, the eye movement direction reversed through a combination of smooth pursuit and saccades. Subsequently, while arm and visual target still moved in opposite directions, smooth pursuit occurred in pace with the visual target motion. Subjects were also submitted to a series of 60 tracking trials, for which the arm-to-target motion relationship was systematically reversed. Under these conditions subjects were able to initiate early smooth pursuit in the actual direction of the visual target. Overall, these results confirm that non-visual information produced by the arm motor system can trigger and control smooth pursuit. They also demonstrate the plasticity of the neuronal network handling eye-arm coordination control.
我们评估了视觉和非视觉信息在跟踪自我移动目标过程中对平稳跟踪运动控制的作用。先前的研究表明，与仅用眼跟踪相比，自我移动目标跟踪的特点是平稳跟踪潜伏期更短、最大速度更高。事实上，当受试者跟踪由其自己手臂控制的视觉目标时，眼球运动和手臂运动紧密同步。在本研究中，我们发现，在自我移动视觉目标的运动方向与手臂运动方向相反的情况下（幅度相同、速度相同，但运动方向相反），由此产生的平稳跟踪眼球运动潜伏期较短，并在手臂运动方向上持续约140毫秒，而不是在实际视觉目标运动方向上。140毫秒后，眼球运动方向通过平稳跟踪和扫视的组合而反转。随后，当手臂和视觉目标仍沿相反方向移动时，平稳跟踪与视觉目标运动同步进行。受试者还进行了一系列60次跟踪试验，在此期间，手臂与目标的运动关系被系统地反转。在这些条件下，受试者能够在视觉目标的实际方向上提前启动平稳跟踪。总体而言，这些结果证实了手臂运动系统产生的非视觉信息可以触发和控制平稳跟踪。它们还证明了处理眼臂协调控制的神经网络的可塑性。
