Analysis
To observe the effects of the early stages of motor learning, we analyzed the improvement rate and changes in the ball-rotation task and brain activity using improvement phases 1 (pre to post1) and 2 (pre to post2).The number of ball rotations was calculated as the average of the two rotations, and the improvement rate was calculated using the following formula: Formula: (post1 or post2−pre)/pre × 100 (pre to post1: improvement phase 1; pre to post2; improvement phase 2).The seven-point Likert scale was used to calculate the median, maximum, and minimum values. Regarding brain activity, the oxy-Hb data that contained a low signal-to-noise ratio in the source and detector placement were removed