The Feasibility, Safety and Tolerability of VR-based Audiovisual Stimulation

Inclusion Criteria Mild AD/ MCI due to AD Participants: * Age between 50 - 90 years old. * A clinical diagnosis of Mild Cognitive Impairment due to Alzheimer's disease (confirmed by PET scan or CSF biomarkers) or Mild Alzheimer's disease * MoCA score of 18-25. * Willingness to sign informed consent document (if deemed to not have the capacity to sign the informed consent, a legally authorized representative will be asked to provide surrogate consent). * Sufficient visual and hearing ability. * Formal education of 8 or more years. * Native English speakers or demonstrated fluency in English (participant; and LAR as needed) Inclusion Criteria Cognitively Healthy Participants: * Age between 50 - 90 years old. * A MoCA score above or equal to 26. * Willingness to sign informed consent document. * Sufficient visual and hearing ability. * Formal education of 8 or more years. * Native English speakers or demonstrated fluency in English (participant) Exclusion Criteria Mild AD/ MCI due to AD Participants: * Previous exposure to monoclonal antibody medication (e.g., Lecanemab, Aducanumab). * Active treatment with Memantine within the past 30 days. * Initiation of acetylcholinesterase inhibitors within the past 30 days. * A history of seizure or epilepsy including family history of seizure or epilepsy. * A history of stroke. * A diagnosis of migraine headache. * History of alcohol use disorder within the past 2 years (DSM-V criteria). * Current or past history of any neurological disorder other than dementia. * Use of hearing aid device(s). * Any known blood pathogens or disorders. * Has any clinically significant medical disorder, condition, disease or clinically significant finding at screening that precludes participant's participation in study activities. * Pregnancy (Verbal confirmation). * Geriatric Depression Scale (GDS) \>8 Exclusion Criteria Cognitively Healthy Participants: * Active treatment with Memantine within the past 30 days. * Initiation of treatment with acetylcholinesterase inhibitors (e.g., donepezil, rivastigmine and galantamine) within the past 30 days. * A history of seizure or epilepsy including family history of seizure or epilepsy. * A history of stroke. * A diagnosis of migraine headache. * History of alcohol use disorder within the past 2 years (DSM-V criteria). * Use of hearing aid device(s). * Any known blood pathogens or disorders. * A diagnosis of Alzheimer's disease and related dementias. * Has any clinically significant medical disorder, condition, disease or clinically significant finding at screening that precludes participant's participation in study activities. * Pregnancy (Verbal confirmation) * Geriatric Depression Scale (GDS) \>8