Abstract
Does force information learned by the motor system influence visual perception of moving targets? Ss trained in one of three force fields (FF) by making reaching movements while holding a robotic manipulandum. The robot applied a constant force to the hand throughout each movement, either in a leftward or rightward direction. For one group no forces were applied (null field). The trained force was also applied during interception, which followed immediately. The target accelerated from left to right and Ss tried to “punch” it. Ss who trained in the rightward FF hit significantly more accelerating targets than the null group and Ss who trained in the leftward FF hit significantly fewer accelerating targets than the null group. All groups initiated their missed responses too late, but timing estimates from the right group were significantly better than those of the left and null groups. In Exp. 2, Ss intercepted the target by pressing a button when the target arrived at the interception point. Again, timing estimates from the right group were better than those of the left and null groups. In Exp. 3, subjects performed the interception task without first training in the FF. We found no influence of concurrent force information on interception performance. These experiments show that force information learned by the motor system affects perception of acceleration, that FF training is needed before this effect is observed, and that access to force information is more effective when one interacts with the visual target than when one responds remotely.