Movement prediction and movement production

The prediction of future positions of moving objects occurs in cases of act ively produced and passively observed movement. Additionally, the moving ob ject may or may not be tracked with the eyes. The authors studied the diffe rence between active and passive movement prediction by asking observers to estimate displacements of an occluded moving target, where the movement wa s driven by the observer's manual action or was passively observed. In the absence of eye tracking, they found that in the active condition, estimates are more anticipatory than in the passive conditions. Decreasing the congr uence between motor action and visual feedback diminished but did not elimi nate the anticipatory effect of action. When the target was tracked with th e eyes, the effect of manual action disappeared. Results indicate distinct contributions of hand and eye movement signals to the prediction of traject ories of moving objects.