Table 2.

Inclusion and exclusion criteria

Inclusion criteria

Age ≥ 70 y CDR score of 0 or 0.5 Sufficient vision and hearing to engage in conversation using personal computer Sufficient English language skills to complete all testing General health status will not interfere with ability to complete longitudinal study (conditions likely to lead this problem were included in the exclusion criteria)

Exclusion criteria

A plan to start taking new classes, traveling requiring > 2 nights away, or participating in significant social events such as a family wedding or family reunion, during the scheduled prevention trial Diseases associated with dementia such as Alzheimer's disease, ischemic vascular dementia, normal pressure hydrocephalus, or Parkinson's disease Significant disease of central nervous system (e.g., brain tumor, seizure disorder, subdural hematoma, cranial arteritis) Current (within previous 2 years) alcohol or substance abuse Current major depression, schizophrenia, or other major psychiatric disorder Unstable or significantly symptomatic cardiovascular disease (e.g., coronary artery disease with frequent angina or congestive heart failure with shortness of breath at rest) Active systemic cancer within 5 years of study entry Illness requires >1 visit per month to a clinician Progressive vision loss (age-related macular degeneration already beginning to significantly degrade vision) Oxygen supplementation required for adequate function Medications  Frequent use of high doses of analgesics  Sedative medications, except for those used occasionally for sleep (use limited to no more than twice per week)  Applicable to CDR of 0.5 group only: Subjects with unstable dosing of cholinesterase inhibitors (stable dosing for 2 months' duration required)

Abbreviation: CDR, clinical dementia rating.