Carbon Dioxide (CO2) and Cognitive Impairment

Inclusion Criteria: * History of COVID-19 vaccination * Weigh at least 110 pounds Exclusion Criteria: * Colorblindness * Inability to hear verbal instructions * Cardiovascular disease, including a history of stroke * Diabetes requiring the use of insulin * Pregnancy * Current asthma (an asthma attack within the past five years) * Medications for or history of anxiety disorder diagnosis or panic attacks * Medications which may affect cognition such as beta-blockers and CNS depressants Temporary Exclusion Criteria * Respiratory symptoms in the previous four weeks * Use of sedating cold/allergy medications in the previous week * Use of marijuana in the previous week * Consumption of alcohol in the previous 24 hours Additional Exclusion Criteria for Subjects undergoing the fMRI scan: * History of head trauma or neurosurgery or neurological disorder * Ferrous metal implanted in or on the body, electrical devices such as a pacemaker, nonremovable ferrous jewelry * Surgical pins or plates above the neck * History of eye injury involving metallic materials, shavings in eyes, or welding without a face mask * Lead or iron tatoos * Claustrophobia * Back problems that would prevent the subject from laying still comfortably for up to 90 minutes Additional Exclusion Criteria for Subjects undergoing CAIM * Current or recent contact lens use