Figure 1.

Setup and Experimental Design. (A) Participants laid in the scanner and put their arm on the arm-rest table to perform a center-out reaching task. To perform the task without moving their head, shoulder, or upper arm, the participant's head was stabilized with foam padding inside the head coil (upper left corner in (A) and fixed using cushioned head stabilizers placed on each side of the head coil (bottom left corner in (A). As additional precautions against head movements and shoulder, the participant's shoulder was stabilized with a strap wrapping across the chest and shoulder. (B) The acrylic panel for the reaching movement. The carved route served to maintain a constant reaching direction for each trial. (C) Example sequence of a trial. There were eight gray target circles in the periphery of the center. The blue circle indicated the target position which to move and the red circle indicated the movement trajectory the participant used to move toward the target direction.