Physical therapy that includes mental practice, or mental imagery, of tasks may be the key to helping stroke patients recover greater arm function. In a study at the University of Cincinnati Medical Center, 32 stroke patients with moderate motor movement disabilities had 30-minute therapy sessions twice a week for six weeks. Half of them followed their therapy sessions with periods in which they mentally practiced performing the skills. The other half had relaxation sessions following their therapy. Patients who mentally practiced the exercises had significantly greater motor-skill and performance improvements than those who relaxed.