Successful computer use requires the operator to link the movement of the cursor to that of his or her hand. Previous studies suggest that the brain establishes this perceptual link through multisensory integration, whereby the causality evidence that drives the integration is provided by the correlated hand and cursor movement trajectories. Here, we explored the temporal window during which this causality evidence is effective. We used a basic cursor-control task, in which participants performed out-and-back reaching movements with their hand on a digitizer tablet. A corresponding cursor movement could be shown on a monitor, yet slightly rotated by an angle that varied from trial to trial. Upon completion of the backward movement, participants judged the endpoint of the outward hand or cursor movement. The mutually biased judgements that typically result reflect the integration of the proprioceptive information on hand endpoint with the visual information on cursor endpoint. We here manipulated the time period during which the cursor was visible, thereby selectively providing causality evidence either before or after sensory information regarding the to-be-judged movement endpoint was available. Specifically, the cursor was visible either during the outward or backward hand movement (conditions Out and Back, respectively). Our data revealed reduced integration in the condition Back compared with the condition Out, suggesting that causality evidence available before the to-be-judged movement endpoint is more powerful than later evidence in determining how strongly the brain integrates the endpoint information. This finding further suggests that sensory integration is not delayed until a judgement is requested.

成功使用计算机需要操作员将光标的移动链接到他或她的手的移动。先前的研究表明，大脑通过多感觉整合建立了这种知觉联系，由此驱动整合的因果证据由相关的手和光标移动轨迹提供。在这里，我们探讨了因果关系证据有效的时间窗口。我们使用了一个基本的光标控制任务，其中，参与者用数字平板电脑上的手来回移动手势。可以在监视器上显示相应的光标移动，但会略微旋转一个角度，该角度因试验而异。向后移动完成后，参与者判断向外的手或光标移动的终点。通常导致的相互偏倚的判断反映了手部端点上的本体感受信息与光标端点上的视觉信息的集成。在这里，我们操纵了可见光标的时间段，从而有选择地提供了有关待判断运动终点的感官信息之前或之后的因果关系证据。具体来说，在向外或向后移动时，光标都是可见的（条件分别为Out和Back）。我们的数据显示，与条件Out相比，条件Back的整合减少，这表明在判断大脑整合端点信息的强度方面，待判定运动终点之前可用的因果证据比后来的证据更有效。这一发现进一步表明，感觉的整合不会延迟，直到需要作出判断为止。