Low-Dose anesthesia may change how pain impacts memory

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Adults, age 18-59, who are native English speakers with at least a high school education * have normal hearing and memory * be of normal body-weight * be generally healthy (free from significant chronic disease) * have none of the specific exclusion criteria * have a valid email address and valid phone number throughout the study * anticipate ability to participate in all visits required for the phase of the study in which they are enrolled Exclusion Criteria: * being pregnant or attempting to conceive * having a body mass index (BMI) \> 35 * having significant memory impairment or hearing loss * having sleep apnea * having chronic pain or frequently taking pain medication (including tramadol) * having any severe or poorly-controlled medical problem (hypertension, diabetes) * having neurologic or psychiatric disease, including anxiety, and depression * having significant cardiac valvular disease or cardiomyopathy * having a history of abnormal heartbeats (cardiac conduction abnormality or arrhythmia) * having a history of seizures or convulsions * having a history of liver disease * having a history of asthma or other significant pulmonary disease * having a history of malignant hyperthermia, muscular dystrophy, central core disease, or hyperkalemia * being claustrophobic * have metal implants or non-removable metal piercings * having a history of adverse reaction to anesthetics * daily alcohol or heavy alcohol use; history of alcohol abuse * current daily smoker * regular or recent marijuana use (including prescribed/medical marijuana) * illicit drug use * regularly taking: antiepileptics, antidepressants, anti-psychotics, antihistamines, anti-anxiety medication, stimulants, or sleep-aids * current use of selective serotonin reuptake inhibitors (SSRIs), noradrenaline reuptake inhibitors (SNRIs), or monoamine oxidase inhibitors (MAOIs) and some other specific drugs phenytoin, carbamazepine, and rifampin * history of QT prolongation * hypersensitivity or allergic reaction to ondansetron (Zofran)