A cross sectional cohort study design with four groups will be implemented to determine how ERPs can provide diagnostic information and alter clinical management beyond that of neuropsychological testing alone in patients with Alzheimer's disease (AD) or Mild Cognitive Impairment (MCI).~Secondary Objectives:~To determine the impact of ERP testing (using cognitive health assessment reports) on change in research grade clinical diagnosis~To determine the degree of correlation between quantitative ERP measures with neuropsychological testing performance using a standardized neuropsychological battery.~75 mild AD dementia and 75 MCI due to any etiology, 25 Older Adults (OA) and 25 Younger Adults (YA) will be enrolled over the course of two years. Each subject will participate in the study for 1 visit.~The in person 50-60-minute testing session consists of a neuropsychological battery, and an EEG session with computer tasks including the Auditory Oddball paradigm, a Continuous Visual Memory Test, Auditory Evoked Potentials, Visual Evoked Potentials, the Erikson Flanker Task, and the Hayling Task.
In this study, the investigators will use a novel electroencephalogram (EEG) system that participants will wear during a single in-person research session to investigate whether ERPs are now ready for validation as a tool clinicians can easily implement to increase diagnostic accuracy and confidence. This EEG will not be used to treat, cure, mitigate or diagnosis any disease and there will be no safety or efficacy data collected about the machine for any purpose including support of FDA submission.~The investigators will compare the ERP data to that of neuropsychological testing in order to determine the degree of correlation between these two measures. Questionnaires on cognition, mood, and fluency will be administered prior to the EEG to establish a baseline. ERP data from the EEG session will be compared with the results of the neuropsychological battery in order to determine whether the implementation of ERPs in the existing workflow of clinicians can aid in diagnostic accuracy, thus altering clinical management.