This is a three year fMRI study conducted at the University of Wisconsin (UW) Hospital and the William. S. Middleton VA Hospital. This study is guided by the hypothesis that reduced fMRI activity and connectivity cortical midline structures (i.e., medial frontal and ventral posterior cingulate cortex) are physiologic abnormalities that relate strongly to the compromised insight into cognitive deficits, or anosognosia, shown by a subset of individuals with amnestic MCI (aMCI) and AD. Further, the investigators hypothesize that these regional changes in fMRI activity are predictive of faster progression from aMCI to AD.

Inclusion Criteria:

• Amnestic MCI:

  1. Observation of memory decline by informant.
  2. Mini Mental Status Exam (MMSE) score between 24 and 30.
  3. Objective memory impairment on neuropsychological tests.
  4. Intact functional abilities, and 4) no diagnosis of dementia.

• AD:

  1. A diagnosis of probable AD according with the NINDS-ADRDA and DSM-IV diagnostic criteria.
  2. MMSE score between 16 and 27. All AD patients will have capacity to provide informed consent as judged by the referring physician.

Exclusion Criteria:

• MRI incompatibility; history of neurologic disease (including prior loss of consciousness of more than 10 minutes); prior neurosurgery; or chronic medical diseases (such as poorly controlled diabetes, renal disease, or poorly controlled hypertension).
• Excluded medications include neuroleptics, short or long acting nitrates, and Warfarin.
• Other exclusions include: less than 10 yrs of education; Hachinski scale of 4 or more; first language other than English; poor visual or auditory acuity; pregnancy.

MCI and AD patients are referred from memory clinics at the UW hospital, William S. Middleton Memorial Veterans Hospital (Madison, WI) and the statewide clinics offered through the Wisconsin Alzheimer's Institute (WAI).