Beta-Blocker Influences on Inflammatory and Neural Responses to Stress

Inclusion Criteria: * Ages 18-30 years * Right-handed * Fluent in English reading, writing, and speaking at least at a 10th grade level * Body mass index (BMI) less than or equal to 35 kg/m\^2 Exclusion Criteria: Assessed as screening, reassessed at Session I: * Non-removeable metal devices/implants/objects in the body * Severe claustrophobia (assessed by self-report) * Currently pregnant * Left-handed * Body mass index (BMI) greater than 35 kg/m\^2 * History of fainting spells or any heart condition * History of or present low resting heart rate (\< 60 BPM) and/or low blood pressure (systolic blood pressure \< 80mmHg) * Self-reported physical illnesses: diabetes, cardiovascular diseases, high blood pressure, inflammatory bowel diseases, rheumatoid arthritis, asthma, autoimmune disease, Crohn's disease, ulcerative colitis, lupus * Any self-reported diagnosed mental illness * Current use of prescription medications (except hormonal contraceptives) * Current or recent regular nicotine/tobacco use (cigarettes, e-cigarettes, vape, chewing tobacco, nicotine gum) * Current regular (daily or almost daily) recreational drug use = 4 or more times per week Instructed against during Session I, reassessed at Session II: * Received any vaccine within the past two weeks * Severe sleep disturbance (3-4 hours of sleep loss) the night before Session II * Vigorous physical activity on the day of Session II * Acute illness or allergy symptoms on the day of Session II * Usage of over-the-counter medications on the day of Session II * Usage of recreational drugs within 48 hours of Session II * Usage of alcohol on the day of Session II