Study Search Results Your query returned 3 results. Series results are grouped under the most relevant study. You can ungroup series results. Results per page: 25 50 100 Sort by: Study Relevance Title A-Z Released/Updated Time Period Most Cited in ICPSR Bib. Most Downloaded Variable Relevance (?) Study Title/Investigator 1. National Survey of Midlife Development in the United States (MIDUS II): Cognitive Project, 2004-2006 (ICPSR 25281) Ryff, Carol D.; Lachman, Margie E. 1 more results in Midlife Development in the United States (MIDUS) Series 2. ACTIVE (Advanced Cognitive Training for Independent and Vital Elderly), 1999-2001 [United States] (ICPSR 4248) Tennstedt, Sharon; Morris, John; Unverzagt, Frederick; et al. 3. Seattle Longitudinal Study (SLS) (ICPSR 158) Schaie, K. Warner; Willis, Sherry L.