Movie 1. Visuomotor stimulus. Cube randomly rotating in 3D about its center. This clip was recorded while a subject manipulated a track ball (see SI Movie 2) to continuously counter rotations of the cube, attempting to keep its blue face up at all times.

Movie 2. Continuous manipulative hand movements during visuomotor control. Continuous fine-tuned hand movements performed by a subject on a track ball to counter the random rotations of the cube (see SI Movie 1).