Can the brain tell real stimulation from sham? a trial investigates

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Age ≥18 years. 2. Self-reported good general health, as assessed by study personnel. Exclusion Criteria: 1. Non-English speaking 2. History of epilepsy, seizure disorder, unprovoked seizure, or status epilepticus. 3. History of febrile seizures beyond early childhood 4. Current use of medications known to substantially lower seizure threshold, including but not limited to certain antidepressants, antipsychotics, stimulants, 5. History of significant neurological disease, including stroke, traumatic brain injury with loss of consciousness, brain tumor, neurodegenerative disease, multiple sclerosis, or other clinically significant neurological disorders. 6. Prior intracranial neurosurgical procedure or implanted neurostimulation device. 7. Presence of an implanted electrical, neurostimulation, cardiac rhythm management, or other active implanted medical device. 8. Significant scalp abnormalities that may interfere with electrode placement, including active skin disease, open wounds, infection, or severe dermatologic conditions involving the scalp. 9. Current diagnosis of a major psychiatric disorder that, in the opinion of the investigator, may interfere with study participation or interpretation of study results. 10. History of severe depression associated with suicidal ideation, suicidal behavior, suicide attempt, psychiatric hospitalization for suicidality. 11. Current suicidal ideation or behavior, as determined by participant self-report. 12. Current substance abuse and/or alcohol dependence that may impair the participant's ability to safely complete study procedures. 13. Pregnant or breastfeeding. 14. Participation in another investigational drug, biologic, or device study within 30 days prior to enrollment, unless approved by the investigator and sponsor. 15. History of migraine with aura, photosensitive migraine, recurrent phosphenes, visually induced neurological symptoms, or other conditions associated with heightened susceptibility to visual sensory phenomena, as determined by the investigator. 16. History of recurrent syncope, unexplained loss of consciousness, vasovagal episodes requiring medical intervention, or other conditions associated with increased risk of fainting during medical procedures or sensory stimulation, as determined by the investigator.