BCI With 40Hz Stimulation in Alzheimer's Disease

Inclusion Criteria: 1. Diagnosis of Alzheimer's disease according to the NIA-AA 2018 diagnostic criteria. 2. Age between 50 and 80 years, inclusive. 3. Positive Aβ-PET scan result. 4. Has a stable caregiver who can assist with daily stimulation intervention. 5. Chronic medical conditions stable for at least 30 days. 6. Adequate vision and hearing to perform testing (at minimum, ability to perceive light and communicate in daily conversation). 7. Good mobility (able to walk independently or with assistive devices). 8. Willing and able to provide voluntary signed informed consent. Exclusion Criteria: 1. History of epilepsy or seizure disorder. 2. Inability to undergo MRI or presence of significant abnormalities on MRI screening. 3. Geriatric Depression Scale (GDS) score \> 6. 4. Current suicidal ideation or suicide attempt within the past 6 months. 5. Other major neurological disorders, including but not limited to: dementia with Lewy bodies, frontotemporal dementia, Huntington's disease, Creutzfeldt-Jakob disease, Down syndrome, or mixed dementia; other neurodegenerative diseases (Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, etc.); history of severe brain infection (meningitis/encephalitis) or multiple concussions; metabolic/systemic diseases causing cognitive impairment (syphilis, vitamin B12 or folate deficiency, etc.). 6. Psychiatric disorders. 7. Severe cardiac disease, chronic liver/kidney/respiratory disease, or uncontrolled diabetes mellitus or thyroid disease. 8. History of drug or alcohol abuse within the past 12 months. 9. Current exposure to anti-Aβ antibody immunotherapies. 10. Current use of memantine within 30 days prior to intervention. 11. Life expectancy \< 24 months.