Personalized Closed-Loop Brain Stimulation for Patients With Mild Cognitive Impairment

Inclusion Criteria: * Must be between 45-85 years of age. * Must be proficient in English. * Must have a minimum of high-school education. * Must be diagnosed with 'probable Alzheimer's Disease (AD)' in specialized diagnostic centers with neuropsychological (e.g., RAVLT) and AD biomarkers according to 2011 guidelines. * The investigators will also perform extensive testing in the investigators' test battery including the Mnemonic Similarity Test (MST) that discriminates and measures the most salient hippocampal deficit-pattern separation (PS). Exclusion Criteria: * People with previous neurological disease including vascular dementia (e.g., stroke, developmental dyslexia, dysgraphia or attentional deficit). * People with hearing loss (\> 25 decibel, using audiometric hearing screen). * People with uncorrected visual acuity loss. * People with advanced dementia or severe language impairments (MMSE \<15, or Montreal Cognitive Assessment \<10, or language Frontotemporal Dementia-specific Clinical Dementia Rating (FTD-CDR) =3). * People with pre-existing psychiatric disorders such as behavioral disturbances, severe depression, or schizophrenia that do not allow these people to comply or follow the study schedule and requirements such as repeated evaluation and therapy.