Proprioception improves temporal accuracy in a coincidence-timing task.

Temporal and spatial information are necessary when pointing to touch moving objects at a specific location. Here, we introduce an interception paradigm that allows us to uncorrelate spatial and temporal errors so that subjects did not have to trade one for the other. We showed the initial trajectories of two objects that moved (laterally or sagittally) with random presentation times and speeds along a collision path. Subjects had to point manually to the collision place at the correct time. We found better temporal accuracy when hand movements matched the motion target direction (e.g., the hand sagittally pointed to a collision point defined along a sagittal trajectory). This temporal selectivity disappeared when subjects had to judge the collision time responding with a single press. The results point to a contribution of proprioceptive information of hand velocity in reducing the temporal uncertainty in a temporal coincidence task.