Effects of covertly shifting starting hand position orthogonally on dominant (red) and non-dominant (blue) arm movements in the lateral direction.

<p><i>(A)</i> Hand trajectories for a single subject. Thin colored lines show individual probe trials, while thick colored lines show the mean of these individual trajectories. Light and dark colors show movements from the top and bottom start positions respectively. Thick black lines represent mean baseline movements. Black crosses represent virtual targets for the shifted start locations, parallel to baseline target direction and at the same distance as the baseline target. Note that subjects saw only the baseline start and target positions. <i>(B)</i> Mean hand trajectories across all subjects from the baseline and shifted start locations. Colors and line types represent the same information as in <i>2A</i>. Gray lines represent SE. <i>(C)</i> Mean direction error at movement end and <i>(D)</i> Mean final position error relative to the baseline target across all subjects, separated by start location [top (light colors), bottom (dark colors)] and arm [dominant (red), non-dominant (blue)]. Error bars represent SE.