Ketamine and Propofol NeuroImaging

Inclusion Criteria:

* Adults 18-59 years of age, who:
* have none of the specific exclusion criteria
* have a valid email address and valid phone number throughout the study
* free from any non-MRI compatible implants

Exclusion Criteria:

* are pregnant or attempting to conceive
* body mass index (BMI) \> 35
* significant memory impairment or hearing loss
* sleep apnea
* chronic pain or frequently taking pain medication
* chronic medical conditions requiring treatment (hypertension, diabetes, high cholesterol)
* neurologic disease, including seizures and tremor
* psychiatric diagnoses, including anxiety, depression, panic, or PTSD
* a history of any of these medical conditions: abnormal heartbeats (cardiac conduction abnormality or arrhythmia), liver or kidney disease, or significant lung disease
* severe claustrophobia or intolerance of an MRI
* have metal implants or non-removable metal piercings
* having a history of adverse reaction to ketamine or propofol
* 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, i.e., street drugs
* regularly taking: antiepileptics, antidepressants, anti-psychotics, antihistamines, anti-anxiety medication, stimulants, or sleep-aids