Multifocal HD-tDCS and Motor Function

Personalizing Multifocal Transcranial Direct Stimulation Dose to Target the Motor Network in Older Adults

The purpose of this study is to understand how the brain controls movement and how Non-invasive Brain Stimulation (NIBS) with a technique called High-density transcranial direct current stimulation (HD-tDCS) can alter brain processes to improve behavior. Participants in this study will be randomized to either HD-tDCS with standard intervention or personalized dose-controlled multifocal network-targeted HD-tDCS.

The hypothesis is that dexterous hand function will improve after a standard HD-tDCS dose and increase even more after personalized dose-controlled multifocal network-targeted HD-tDCS.

This project is the first of two projects. The second project will be registered as a separate project in the future and enroll participants from this project.

Inclusion Criteria:

• Participants should be in good health with normal or corrected-to-normal visual acuity
• Right handed
• No history of neurological disorder
• English speaker
• Able to provide written consent prior to admission

Exclusion Criteria:

• Left-handed
• Participants are pregnant, suspect pregnancy or are attempting to become pregnant
• Have a pacemaker, intracardiac lines or any other medically implanted device or medicine pump
• Have cochlear hearing implants
• Taking drugs known to influence neural receptors that facilitate neuroplasticity (see protocol)
• Have non removable body piercings or have foreign objects in body
• Have metal anywhere in the head that could increase risk of serious injury (not including braces, dental fillings, etc.) (see protocol)
• Have a personal or family history of seizure/epilepsy
• Taking prescription drugs that lower the threshold for seizures
• Recent history of excessive alcohol consumption
• History of alcohol addiction/dependence
• Recent history of recreational drug use
• History of drug addiction/dependence
• Recent history of recreational drug use
• History of drug addiction/dependence
• Diagnosed with a stroke, brain hemorrhage, brain tumor, encephalitis.
• Diagnosed with multiple sclerosis
• Diagnosed with Parkinson's disease or Alzheimer's disease
• Diagnosed with depression in the past 6 months
• Diagnosed with attention deficit disorder, schizophrenia, manic depressive (bipolar) disorder
• Diagnosed with normal pressure hydrocephalus or increased intra-cranial pressure
• Diabetes requiring insulin treatment
• Any serious heart disorder or liver disease