Mild cognitive impairment (MCI) is a brain function syndrome involving the onset and evolution of cognitive impairments beyond those expected based on the age and education of the individual. In this book, the authors discuss the symptoms, causes, risk factors and clinical outcomes of MCI. Topics include cognitive decline in MCI and Alzheimer's disease and β-amyloidosis and tauopathy versus cerebrovascular risk; the relationship between EEG Alpha3/Alpha2 ratio and the nucleus accumbens in subjects with Mild Cognitive Impairment; brain correlates of impaired clock drawing performance in MCI and Alzheimer's disease; and a new test for the early uptake of Alzheimer's disease.