Clinical Trials

Inclusion Criteria 

1. Men and women 
2. Age: 40-80 yrs 
3. English speaking 
4. Physically mobile (enough to get an MRI).

Exclusion Criteria 

1. Prior significant neurological disorder (e.g., dementia, seizure disorder, moderate or severe traumatic brain injury) 
2. We will exclude participants from analysis and further enrollment (follow-up visits) who reveal dementia based on NINDS-AIREN criteria
3. Major psychiatric disturbance (e.g., schizophrenia, chronic intractable depression, substance abuse) 
4. Evidence of major ischemic or hemorrhagic stroke
5. Other unstable medical conditions (e.g. cancer; basal cell skin and limited prostate cancer are acceptable) 
6. MRI contraindications (e.g., pregnancy, claustrophobia, metal implants, circumference > 60 inches, weight > 425 lbs) 
7. Physical impairment precluding motor response or lying still for 1 hr.
8. Use of medications known to influence cognitive functions (e.g., benzodiazepines, barbiturates, antipsychotics)
9. Cardiac pacemaker dependence