When interacting with the environment, our manual actions are often preceded by an eye movement. This suggests that the processes underlying target selection in hand and eye movements may be coupled. It is known that when a distractor is presented close to a target, the endpoint of an eye movement will be biased towards the distractor. The size of this so-called global effect decreases when more viewing time is available. Here we investigate whether a similar effect is also present in hand movements. If the processes underlying target selection for hand and eye movements are indeed coupled, a similar bias should be present in hand movements as well. To test this, we adopted a classic global effect paradigm but applied it to goal-directed hand movements. We show that the endpoints of hand movements are unbiased for all but one participant, irrespective of the viewing time. These results suggest that the processes underlying target selection for hand movements operate independently from those for eye movements.

在与环境交互时，我们的手动操作通常先于眼球运动。这表明手和眼运动中目标选择的潜在过程可能是耦合的。众所周知，当干扰物靠近目标时，眼球运动的终点会偏向于干扰物。当更多的观看时间可用时，这种所谓的全局效应的大小会减小。在这里，我们调查手部运动中是否也存在类似的效果。如果手部运动和眼部运动的目标选择过程确实是耦合的，那么手部运动中也应该存在类似的偏差。为了测试这一点，我们采用了经典的全局效应范式，但将其应用于目标导向的手部运动。我们表明，除了一名参与者，手部运动的终点对所有参与者都是无偏的，与观看时间无关。这些结果表明，手部运动目标选择的过程独立于眼部运动。