Assessing Covert Consciousness During Dexmedetomidine and Ketamine Sedation: An fMRI Study

Inclusion Criteria:

* Healthy study subjects with American Society of Anesthesiologists (ASA)-1 status
* Right-handed
* Body mass index (BMI) less than 30
* Participants will have the experience of playing tennis (or other racquet sport) at least 30 times in their lifetime
* English speaking

Exclusion Criteria:

* Medical contraindication to MRI scanning; are unable to undergo MRI scanning because of possible pregnancy or currently breastfeeding
* BMI greater than or equal to 30
* Metallic substances in the body
* claustrophobia, anxiety, or cardiopulmonary disease; or have an intracranial structural abnormality on T1-weighted MRI scans
* history of allergy to dexmedetomidine, ketamine, propofol, or any components of these medications, eggs or egg products, soybean or soybean products
* neurological, cardiovascular, or pulmonary illness
* significant head injury with loss of consciousness; learning disability or other developmental disorder
* sleep apnea or any severe snoring history
* gastroesophageal reflux disease (GERD) or heartburn; pancreatitis or a history of pancreatitis,
* sensory/motor loss sufficient to interfere with performance of the study
* epilepsy/seizure disorder (including a history of seizures) or stroke (including a history of stroke).
* history of schizophrenia spectrum disorder, bipolar disorder, other psychotic disorder, or any prior adverse psychiatric reaction to ketamine or similar drugs
* Participants taking medications that, in the judgment of the investigators or attending anesthesiologist, may interact with the study drugs or increase the risk of participation will also be excluded
* participants with hypertension or diabetes mellitus
* tattoos in the head or neck region will be excluded from study; other tattoos are subject to determination by investigators based on their assessment regarding participant safety
* recent food or liquid intake (within 8 hours)
* history of drug use, have a positive drug screen, are unwilling to abstain from alcohol for 24 hours prior to dosing, or have a current history of nicotine use.
* Potential participants who have participated in a clinical trial using an investigational drug or device within 30 days will be considered for enrollment after 30 days.
* History of a difficult airway with a previous anesthetic