Evaluation of a Handheld Event Related Potential (ERP)/Quantitative Electroencephalography (qEEG) System (COGNISION™) as a Useful Cognitive Biomarker for Alzheimer's Disease.

The study will be : A. Multi-Center Study: primary goal of this study will be to evaluate the COGNISION™ Platform across multiple study locations. This will demonstrate an ability to perform tests, collect data, and generate classifications irrespective of variations in testing locations and personnel. 1. 5-8 study sites will be selected with each site being a recognized NIH Center of Excellence for Alzheimer's disease or other nationally recognized Alzheimer's disease research center. 2. Each site will evaluate up to 60 subjects evenly divided between AD patients and age-matched controls (while the prevalence of AD is approximately 2% in the general population, the ratio of AD to normal among those who visit a clinic for memory or cognitive related issues is between 50-60%). 3. Each site will follow the same testing protocols. 4. All test data will be uploaded to the online COGNISION™ database server.