Cognitive aging and cognitive decline are important public health concerns in an aging US population. The investigators will conduct a randomized controlled trail among healthy older adults to assess effects of several innovative activities on remediation of age-related cognitive decline.

ACE-Seniors is designed as a single-site trial of four randomly assigned interventions, Tai Chi exercise, autobiographical writing, both Tai Chi and autobiography (dual intervention), and general health education. Participants are relatively healthy adults aged 70 years or older, who are not regular practitioners of Tai Chi or regular writers. They are without medical or neurological disorders that would substantially limit the ability to participate in study interventions, without dementia or mild cognitive impairment, relatively sedentary, able to walk unassisted, and able to score 4 or better on the Short Physical Performance Battery. Interventions are administered over a 6 month period of time, with similar exposure times among the four groups. The prespecified primary endpoint is derived from a composite neuropsychological measure, based on three tests of executive function and three tests of episodic memory. The planned sample size is 96 (24 per group). Intention-to-treat analysis will include all eligible participants who complete baseline assessments.

Inclusion Criteria:

• 70 years of age or older.
• No other household member already enrolled.
• In reasonably good health: no serious cognitive problem; free of any condition that would limit your ability to participate in Tai Chi classes (a moderate intensity exercise), in Qigong exercises, in a writing program, or in a seminar series.
• Not presently engaged in a regular exercise program; not presently engaged in Tai Chi Qigong or another form of Eastern exercise; and not a regular writer.
• Not now engaged in research to enhance cognitive skills.
• Willing to travel to Stanford for ACE-Seniors program classes. Planning to be in the area during most of the coming year;
• Willing to be assigned randomly (by chance) to one of the ACE-Senior activities.

Exclusion Criteria:

• Failure to meet inclusion criteria.