Sessions II-V: Patients will sit in front of a computer screen and will play a simple computer game by moving a cursor using a Joystick, and reaching the target on the screen. Each block of reaching movements will be conducted with the same hand, and different blocks will be conducted with the affected or unaffected hands. During reaching movements with the unaffected hand there will be random jumps in the position of the target and/or cursor. The number of reaching movements in each block will be adjusted to the comfort of each patient, but will be limited to 50. A total of 250 reaching movements will be performed with each hand, over 60-120min depending on the number and duration of the breaks. The experiment will be conducted over 1-4 sessions depending on how long the patient will be able to participate in each day.