<qa>  What is the purpose of this study?This study is being performed to generate data regarding brain vibration oscillation differences between individuals with dementia and normal controls. The purpose of this study is to compare signal patterns generated from the impact on the scalp from these brain oscillation patterns from individuals with Alzheimers disease, Frontotemporal Lobar Degeneration, Mild Cognitive Impairment and Age-Matched Normal Controls. 