Fig. 1.

Experimental design. The black lines indicate the extent of angular rotation of visual feedback of the movement trajectory relative to the center of the start circle. Positive values indicate clockwise rotation; negative values indicate counterclockwise rotation. In the no prior error conditions (Err⁻Rep⁻ and Err⁻Rep⁺; left), the 30° clockwise rotation in first adaptation block A1 was gradually removed to prevent experience of the 30° counterclockwise error in that would be later encountered in savings block B. In the prior error conditions (Err⁺Rep⁻ and Err⁺Rep⁺; right), the abruptly imposed 30° clockwise rotation at block A1 was abruptly removed to allow experience of large counterclockwise errors that would be later encountered in savings block B. The blue dotted lines indicate the target direction (0° = 12 o'clock, 90° = 3 o'clock, −90°= 9 o'clock, and 180° = 6 o'clock), which was manipulated to encourage repetition of the savings block B movement solution in the prior repetition conditions (Err⁻Rep⁺ and Err⁺Rep⁺), such that the movement solution in all blocks before savings block B (indicated by the orange lines) was the same as in savings block B.