Imaging Brain Fluids During Breathing

Exclusion Criteria16

• No ferrous metal implanted in head or body
• No history of major head trauma
• No neurological or psychiatric disorder
• Not using medication that affects brain function
• No implanted electronic devices (e.g. pacemaker)
• No implant that poses an MR contraindication
• Not pregnant, suspect they are pregnant, or seeking to become pregnant
• Not claustrophobic
• No piercings or jewelry that cannot be removed
• Does not weigh more than 250 pounds
• Normal or contact-corrected normal vision
• Exclusion for transcutaneous vagus nerve stimulation (tVNS) arm:
• Conditions of skin or anatomy that affect left auricle or forehead skin and could impact placement of electrodes for tVNS or forehead stimulation
• Diagnosis of significant cardiovascular or cerebrovascular disease \[e.g. congestive heart failure, stroke, cardiac conduction disorders (including: bundle branch block, heart block, long Q-T syndrome), history of asystole or non-sustained ventricular tachycardia.
• Bradycardia (defined as resting heart rate <50 bpm)
• Hypotension defined as blood pressure <90/60 mmHg