Centre for Neuroscience, Indian Institute of Science, Bangalore, India.
J Mot Behav. 2021;53(1):47-58. doi: 10.1080/00222895.2020.1723481. Epub 2020 Feb 11.
Eye and hand movements are often made in isolation but for reaching movements they are usually coupled. Despite this, evidence for spatial coupling between the eye and hand effector is mixed and have usually been restricted to straight-line movements, while real-world hand movements have complex trajectories. Here, using a novel obstacle avoidance task where an obstacle appeared in an infrequent number of trials, we establish a stronger link between the saccade and hand trajectory during more naturalistic curved hand trajectories. We illustrate that the hand trajectory was coupled to the end-point of the saccade which was executed just prior to the hand movement onset. Interestingly, while the saccade end-point was related to whether the hand trajectory followed a straight or a curved path, the y-component of saccade end-point was related to whether the hand took a path passing from over or below the obstacle. Further, we observed a relationship between saccade locations and hand sub-movements where the number and timing of saccades and number of hand velocity peaks were related. These results illustrate a robust spatiotemporal and kinematic coupling between saccades and complex hand movement trajectories suggesting a shared kinematic representation underlying eye-hand movements.
眼动和手动通常是孤立进行的，但在伸手动作中，它们通常是耦合的。尽管如此，眼手效应器之间的空间耦合的证据是混杂的，并且通常仅限于直线运动，而现实世界中的手运动具有复杂的轨迹。在这里，我们使用一种新颖的障碍物回避任务，其中障碍物在少数几次试验中出现，我们在更自然的弯曲手轨迹中建立了眼跳和手轨迹之间更强的联系。我们说明手轨迹与在手部运动开始之前执行的眼跳的终点耦合。有趣的是，虽然眼跳终点与手轨迹是遵循直线还是曲线路径有关，但眼跳终点的 y 分量与手是否沿路径通过障碍物上方或下方有关。此外，我们观察到手部亚运动的眼跳位置之间存在关系，其中眼跳的次数和时间以及手部速度峰值的数量有关。这些结果表明，眼跳和复杂的手部运动轨迹之间存在强大的时空和运动学耦合，这表明眼手运动的基础存在共享的运动学表示。
