Search Results Use the search box below to revise your search, or start a new search. Studies (4) Variables Publications Your query returned 3 studies. Series results are grouped under the most relevant study. Ungroup series results to view all results. Sort by: Study Relevance Title A-Z Released/Updated Time Period Most Cited in ICPSR Bib. Variable Relevance 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 result 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.