Multisensory 40-Hz Stimulation for Alzheimer's Disease

Inclusion Criteria: 1. Provision of written informed consent by the participant or the participant's legally authorized representative. 2. Age 45 to 75 years, inclusive. 3. Completion of at least primary school education. 4. Diagnosis within the Alzheimer's disease spectrum according to the National 5.Institute on Aging and Alzheimer's Association criteria. Mild cognitive impairment due to Alzheimer's disease or mild Alzheimer's disease dementia, defined by a Montreal Cognitive Assessment score of ≤24 for participants with middle school education or above, or ≤23 for participants with primary school education, and a Clinical Dementia Rating global score of 0.5 or 1. 6.Evidence of Alzheimer's disease pathology based on a positive positron emission tomography, cerebrospinal fluid, or blood biomarker result. 7.Alzheimer's disease-related medications are expected to remain stable during the study period. Exclusion Criteria: 1. Current or previous history of a neurological disorder other than Alzheimer's disease that may affect cognition or study assessments, including epilepsy, stroke, multiple sclerosis, poorly controlled migraine, intracranial injury, previous neurosurgery, or head trauma with residual neurological impairment. 2. Contraindication to magnetic resonance imaging, electroencephalography, auditory stimulation, visual stimulation, or noninvasive brain stimulation. 3. Current major depressive disorder or another psychiatric disorder that, in the investigator's judgment, may interfere with study participation or outcome assessment. 4. Clinically significant structural abnormalities on brain magnetic resonance imaging, including hydrocephalus, stroke, or another structural lesion that may confound study results. 5. Severe cardiovascular or pulmonary disease. 6. Cognitive impairment primarily attributable to another disorder, including frontotemporal dementia, dementia with Lewy bodies, Parkinson's disease dementia, or vascular dementia. 7. Clinically significant suicide risk or a suicide attempt within the previous 12 months. 8. Behavioral disturbance, including severe aggression, agitation, or impulsivity, that may interfere with adherence to study procedures. 9. Current or planned treatment with an anti-amyloid monoclonal antibody during the study period. 10. Any other condition that, in the investigator's judgment, makes the participant unsuitable for the study.