We propose to develop regression models using neuroimaging, neuropsychology, and other clinical and demographic variables as independent variables. Dependent variables would include functional assessment and diagnostic or pathologic variables. Other analytic techniques would include cluster analysis and item response theory models. We are interested in investigating subtypes of cognitive impairment, especially in terms of cognitive and functional decline. We are especially interested in cerebral small vessel disease contributions to mixed Alzheimer's and vascular cognitive impairment.