Fig. 2.

Locomotor sequence learning. Each sequence consisted of 6 steps, and each block consisted of 16 complete sequences. A: performance in a typical subject over 7 blocks. Score (left y-axis, maximum score = 100) is the total number of hits in each block (top x-axis). Success rate (right y-axis) is the fraction of hits within each 6-step sequence (bottom x-axis). Score (bar graph) and success rate (line graph) for the same subject are overlaid on the plot to show variability within each block. B: mean success rate for each sequence averaged across subjects (n = 10). Shaded area of the curve represents standard error (SE). C: mean score (number of hits) over 7 blocks of testing averaged across subjects (n = 10). D: nonspecific learning (R3 − R2) and sequence-specific learning (S3 − R3) for individual subjects. E: group average mean error (n = 10) in the anterior-posterior (AP) direction, calculated as the foot position (5th MT) relative to the target position. Error was normalized to each subject's leg length. F: group average cadence (n = 10). *P < 0.05; ns, not significant.