Temporal Interference Methods for Non-invasive Deep Brain Stimulation, Study 1.3

This grant aims to develop a line of research using temporal interference (TI) electrical neurostimulation technology to understand the causal role of deep brain structures in cognition. In the short term, the investigators aim to validate and characterize the effects of TI on brain activity as measured by fMRI and demonstrate its ability to focally stimulate deep brain regions without affecting overlying cortex. In the longer term, investigators aim to use these data to resolve longstanding debates about the function of deeper brain regions and lay the foundation for future clinical applications of TI for treating addiction, Obsessive-Compulsive Disorder (OCD), Parkinson's disease, and other disorders involving deep brain dysfunction. The grant supports 2 distinct aims, each of which will be evaluated through a series of independent studies.

Inclusion Criteria: * Between the ages of 18 and 50 * Must have at least a 6th grade education * Ability to speak and read English for all phases Exclusion Criteria: * Currently taking psychotropic medications for ADHD, other mental illness, or medications for cancer * History of epilepsy or seizure disorders * History of migraines or other neurological syndromes * History of AIDS (due to potential cognitive deficits) * History of head trauma or cognitive impairments * Personal experiences consistent with symptoms of psychosis (e.g., hallucinations, delusions of control or special powers) * History of skull defects (e.g., holes bored into the skull or known cranial fissures) * Metal implants in the head or under the scalp * Does not meet fMRI safety screening criteria (e.g., metal implants in the body, permanent jewelry, tattoos on the head or neck) * Uses an intrauterine device (IUD) for birth control and cannot provide documentation to verify MRI safety * Pregnancy (self-reported; no pregnancy test administered) * Weight over 440 lbs (scanner weight limit) * Presence of pacemakers