Clinical Research Directory

Inclusion Criteria: * Men and women of all races or ethnicity * Age 18-60 * Healthy volunteers or previously diagnosed with POTS by current consensus criteria (rise in heart rate of at least 30 beats/minute within 10 minutes of standing; absence of orthostatic hypotension defined as a drop in blood pressure greater than 20/10 mmHg within 3 minutes of standing; and presence of daily orthostatic symptoms for at least 6 months such as lightheadedness, dizziness, nausea, and palpitations). * Healthy participants must have cognitive testing scores within normal range (defined by Stroop word-color test score between 40-70) and be able to tolerate lower body negative pressure. * POTS participants must have either mild cognitive dysfunction (defined by Stroop word-color t-score \<40 and \>30) or normal cognitive function (defined by Stroop word-color test score between 40-70), and able to tolerate lower body negative pressure. * Capable of giving informed consent * Fluent in written and spoken English Exclusion Criteria: * Age \<18 years or \>60 years * Pregnant or breastfeeding women * Left handedness * Require glasses for vision correction (contact lenses are okay) * Current smokers * Alcohol or drug abuse * Recreational drug use (e.g. cannabis, heroin, cocaine) * Other potential causes for tachycardia (e.g. prolonged bed rest, dehydration) * Taking selective norepinephrine reuptake inhibitors or stimulant medications within the past 3 months as these may alter cognition * Unable to tolerate an MRI scanner (e.g. claustrophobia, implanted metal) * Unable to give or withdraw informed consent