Li Yuhui, Wang Yong, Cui He
Brain and Behavior Discovery Institute, Medical College of Georgia, Augusta University , Augusta, Georgia.
State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences , Beijing , China.
J Neurophysiol. 2018 Jan 1;119(1):221-234. doi: 10.1152/jn.00476.2017. Epub 2017 Oct 11.
As a vital skill in an evolving world, interception of moving objects relies on accurate prediction of target motion. In natural circumstances, active gaze shifts often accompany hand movements when exploring targets of interest, but how eye and hand movements are coordinated during manual interception and their dependence on visual prediction remain unclear. Here, we trained gaze-unrestrained monkeys to manually intercept targets appearing at random locations and circularly moving with random speeds. We found that well-trained animals were able to intercept the targets with adequate compensation for both sensory transmission and motor delays. Before interception, the animals' gaze followed the targets with adequate compensation for the sensory delay, but not for extra target displacement during the eye movements. Both hand and eye movements were modulated by target kinematics, and their reaction times were correlated. Moreover, retinal errors and reaching errors were correlated across different stages of reach execution. Our results reveal eye-hand coordination during manual interception, yet the eye and hand movements may show different levels of prediction based on the task context. NEW & NOTEWORTHY Here we studied the eye-hand coordination of monkeys during flexible manual interception of a moving target. Eye movements were untrained and not explicitly associated with reward. We found that the initial saccades toward the moving target adequately compensated for sensory transmission delays, but not for extra target displacement, whereas the reaching arm movements fully compensated for sensorimotor delays, suggesting that the mode of eye-hand coordination strongly depends on behavioral context.
作为不断发展的世界中的一项重要技能，拦截移动物体依赖于对目标运动的准确预测。在自然环境中，当探索感兴趣的目标时，主动的目光转移通常伴随着手部动作，但在手动拦截过程中眼睛和手部动作是如何协调的，以及它们对视觉预测的依赖程度仍不清楚。在这里，我们训练了目光不受限制的猴子手动拦截随机位置出现并以随机速度做圆周运动的目标。我们发现，训练有素的动物能够在充分补偿感觉传导和运动延迟的情况下拦截目标。在拦截之前，动物的目光跟随目标，对感觉延迟进行了充分补偿，但对眼球运动过程中的额外目标位移没有进行补偿。手部和眼部动作均受目标运动学调制，且它们的反应时间相关。此外，在伸手执行的不同阶段，视网膜误差和伸手误差相关。我们的结果揭示了手动拦截过程中的眼手协调，但基于任务背景，眼睛和手部动作可能表现出不同程度的预测。新发现与值得注意之处 在这里，我们研究了猴子在灵活手动拦截移动目标过程中的眼手协调。眼球运动未经过训练，且与奖励没有明确关联。我们发现，朝向移动目标的初始扫视充分补偿了感觉传导延迟，但没有补偿额外的目标位移，而伸手的手臂动作则完全补偿了感觉运动延迟，这表明眼手协调模式强烈依赖于行为背景。
