Fig 1. Experimental setup and paradigm.

(A) Participants grasped the handle of a robotic manipulandum (vBOT) that could generate forces in the horizontal plane. Visual stimuli and feedback of movements were presented using a top-mounted computer monitor seen via a mirror. (B) Participants made a reaching movement for one of eight possible targets in each trial. The 0° target was used for both training trials (for adaptation to a novel gain) and probe trials (for evaluation of generalization function) while the other seven targets were used only for probe trials. All trials were performed under a force channel environment generated by vBOT. (C) Trial structure in the four phases of the experiment. The success zone shows the range of reach distances required for binary success feedback across the experiment.