Other concomitant respiratory disorder other than asthma (e.g., cystic fibrosis), Use of antibiotics or steroids for a COPD exacerbation within the past month, Use of 24-hour oxygen, Pregnancy or suspected pregnancy, Uncontrolled cancer within the last 5 years, Radiation therapy to the chest, Lung surgery (LVRS, transplant, lobectomy), Lung cancer known or suspected, Eye surgery in the last 3 months, Pulmonary Hypertension, Insulin-dependent diabetes, Inability to use albuterol, Chest or abdominal surgery in the past 3 months, Heart attack in the last 3 months, Hospitalization for any heart problem in the past month, Prior neurological condition (e.g., stroke, epilepsy, head injury with >15 mins. loss of consciousness), Previous diagnosis of dementia or learning disability, Major comorbid medical conditions with known cognitive effects (e.g., renal failure, HF), Psychotic disorder, bipolar disorder, current substance use disorder other than tobacco use, Change in psychiatric medication in last month, Claustrophobia, Metal object in body that may interfere with neuroimaging.