A 68-yeаr оld pаtient hаs chief cоmplaint оf depressed mood. The patient walks in with a slow gain and stooped posture. The APRN notes a rigid facial expression and symptoms of mild depression. ROS includes hand tremors. When the patient is asked to write during the mini mental status exam, small, cramped writing is noted. The patient has not been prescribed psychotropic medications. Given the symptoms, the most likely area of the brain involved in this symptom expression is: