Abstract

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.

摘要

眼和手的动作通常是孤立的，但是为了达到动作，它们通常是耦合的。尽管如此，眼部和手部执行器之间空间耦合的证据仍然混杂，并且通常仅限于直线运动，而现实世界中的手部运动具有复杂的轨迹。在这里，使用一种新颖的避障任务，即在很少次数的试验中出现障碍，我们在更自然的弯曲手形轨迹中建立扫视和手形轨迹之间的更牢固联系。我们说明了手的轨迹与扫视的端点相关，扫视的端点是在手开始运动之前执行的。有趣的是，扫视端点与手轨迹是直线还是曲线有关，扫视端点的y分量与手是否通过障碍物上方或下方的路径有关。此外，我们观察到扫视位置和手子动作之间的关系，其中扫视的数量和时间与手速度峰值的数量相关。这些结果说明了扫视与复杂的手部运动轨迹之间的鲁棒的时空和运动学耦合，表明了眼睛手部运动背后的共同运动学表示。