Although some dimensions of human abilities remain stable over the life span, or in some cases even develop and expand with age and greater maturity (e.g., the ability to exercise good sense and sound judgment), there is general agreement that systematic age-related declines in cognitive functioning occur in midlife and older age across multiple domains, including speed of processing, episodic memory, attention, and verbal fluency. Cognitive function is clearly an essential component of health and well-being across the life span, and understanding the relationship of aging to cognitive function is increasingly a high priority for society because of the realities of population aging and because of its intrinsic relevance to the lives of aging members of society. Moreover, differences in patterns of cognitive aging are crucial to understanding the linkages among socioeconomic, racial/ethnic, gender, and health disparities.

This is an exciting period in which to study the connection between processes of aging and cognitive function; progress is being made on several fronts. This was the conclusion of the National Research Council's (NRC's) Committee on Future Directions for Cognitive Research on Aging, articulated in The Aging Mind: Opportunities in Cognitive Research.1“Now is a time of great promise for learning more about the aging mind and turning that knowledge to the advantage of older people,” the NRC report concluded (2000, p. 8). The committee cited discoveries being made by neuroscientists in understanding the neural basis of many cognitive functions. They concluded that the adult brain “has much greater capacity for plasticity than previously believed, growing new dendrites and perhaps even new neurons” (p. 7), asserting that neuroscientists “are poised to understand, at the molecular and cellular levels, neural changes that affect the life course of cognitive capabilities” (p. 8). In the area of behavioral science, the committee reported that rapid progress had been made in “classifying types of cognitive functioning, measuring them, tracking changes in particular functions over the life cycle, and documenting declines, maintenance, and improvement in these functions over the life span” (p. 8). They argued that “this research is making it possible to develop behavioral and technological interventions to maintain cognitive performance in older individuals” (p. 8). The committee further observed that “researchers in cognitive science are developing detailed models and theories of cognitive processes that can help make sense of observed patterns of change in functioning and link them to observed changes in neural systems” (p. 8). Finally, they noted that social scientists have demonstrated “the significance of cultural supports and life experiences in shaping cognitive content and processes over the life span” (p. 8). All these developments “are making possible new understandings of how normal processes of aging affect cognitive functioning and new interventions to maintain cognitive performance in older people” (p. 1).

Despite the impressive claims made by the NRC report for knowledge in the field of cognitive aging, it also stressed the need for several major research initiatives that promise to contribute to the improvement of knowledge regarding age-related change in cognitive functioning. One of the central observations articulated in [Page xi]The Aging Mind was that, although there is “much valuable and promising research” going on across the fields of neuroscience, behavioral (psychological) science, and social science, these “fields do not communicate with each other as much as is probably desirable” and that “what is being learned from each research perspective has not fully penetrated the work of researchers proceeding from other perspectives” (pp. 8–9). The committee argued that the state of our current knowledge about the nature of cognitive aging is encumbered by the failure to develop a comprehensive theoretical framework that incorporates age-related variation in environmental factors, age-related changes in sensory function and health, and the interaction of these factors with neurological changes in development. They proposed a conceptual framework that focused on three interacting systems: cognitive structures and processes, neural health, and behavioral context, including task structure and social, cultural, and technological factors” (pp. 9–11). The implications of this framework for setting the agenda of the future of cognitive aging are far reaching, and we believe they will not go unrecognized by researchers working on these problems across disciplines.

In addition to summarizing the existing knowledge about developments in cognitive aging research, the NRC committee also viewed their task as one of identifying “areas of opportunity in which additional research support from the National Institute on Aging (NIA) would substantially improve understanding of cognitive functioning” (p. 1). They identified a number of serious limitations in research design, data collection, multivariate statistical modeling, and the development of research strategies that adhere to the highest standards for internal and external validity. Indeed, the NRC was quite explicit in the “Research Initiative” section of its report with regard to the requirements of future research on cognitive aging. The report argued that, to achieve the objectives of the recommended research initiatives,

The report went on to argue that it is also “important to examine a broad representative sample of the population, sometimes oversampling in subgroups whose health status or responses to life experiences are expected to illuminate important theoretical questions, and to encompass a wide age range” (p. 52). Finally, the report argued that “by following individuals into very old age, promising new findings suggesting the existence of unexpected linkages between cognitive functioning and survival could be investigated” (p. 52).

Building in part upon the mandates set by the NRC committee in The Aging Mind, the present volume is based on the activities and results of the International Conference on the Future of Cognitive Aging Research (ICFCAR), held at Pennsylvania State University May 20–22, 2005, which was aimed at contributing to a conversation that would confront some of these obstacles to progress in research identified by the NRC committee, with an eye toward developing a shared multidisciplinary agenda for the next few decades of research. The conference was intended in part to employ a somewhat broader compass for the inclusion of cognitive aging researchers in these important discussions. Our recruitment efforts resulted in our gaining the participation of a diverse group of scholars who work in the field of cognitive aging.

The ICFCAR conference was supported in part by a grant award to Pennsylvania State University on behalf of Duane F. Alwin and Scott M. Hofer from the National Institute on Aging (R13-AG02623), and specifically by programs within the Behavioral and Social Research and Neuroscience and Neuropsychology branches of the NIA. The ICFCAR was also cosponsored and supported financially by the Social Science Research Institute, the College of Health and Human Development, and the College of the Liberal Arts, all of Pennsylvania State University, as well as by the Center for Demography of Health and Aging at the University of Wisconsin.

Leading international experts on cognitive aging representing the fields of developmental psychology, psychiatry, neuroscience, behavioral [Page xii]genetics, demography, gerontology, sociology, economics, biostatistics, and epidemiology gathered for a 3-day working conference, focusing on the state of research in the field of cognitive aging and its future. The ICFCAR conference attracted top researchers from Australia, England, Scotland, Germany, Switzerland, Sweden, the Netherlands, and the United States, countries where the majority of research on cognitive aging is done.2 The five main objectives of the ICFCAR were to explore (1) the current state of the cognitive theorizing as related to processes of aging, (2) present-day empirical assessments of what is known about cognitive aging phenomena in terms of changes and causes, (3) methodological critiques of research designs and measurement models on which our current knowledge base rests, (4) the discussion of alternative designs and innovative lines of interdisciplinary research that promise new insights into the processes of cognitive aging, and (5) the critical issues of the data needs for the future.

More than 60 internationally recognized experts on various aspects cognitive aging were invited to attend the ICFCAR, most of who have made a contribution to the present volume. The following researcher/scholars were in attendance:3 David M. Almeida (Pennsylvania State University), Kaarin Anstey (Australian National University), Paul Baltes (Max Planck Institute, Germany), Lisa L. Barnes (Rush University Medical Center), Cynthia A. Berg (University of Utah), Fredda Blanchard-Fields (Georgia Institute of Technology), Herman Buschke (Albert Einstein Medical School), Roberto Cabeza (Duke University), Neil Charness (Florida State University), Helen Christensen (Australian National University), Fergus I. M. Craik (University of Toronto, Canada), Dale Dannefer (Case Western Reserve University), Gordon DeJong (Pennsylvania State University), Roger A. Dixon (University of Alberta), Gwenith G. Fisher (University of Michigan), Paul Eslinger (Pennsylvania State University Hershey Medical Center), Jeremy Freese (University of Wisconsin-Madison), Robert M. Hauser (University of Wisconsin-Madison), Steven G. Heeringa (University of Michigan), Christopher Hertzog (Georgia Institute of Technology), Lesa Hoffman (University of Nebraska), John L. Horn (University of Southern California), William J. Hoyer (Syracuse University), Boo Johansson (Gteborg University, Sweden), Susan Kemper (University of Kansas), Shinobu Kitayama (University of Michigan), Margie E. Lachman (Brandeis University), Ulman Lindenberger (Max Planck Institute, Germany), Mary A. Luszcz (Flinders University, Australia), Jennifer Manly (Columbia University), Mike Martin (University of Zurich, Switzerland), John J. McArdle (University of Virginia, now at the University of Southern California), Ryan J. McCammon (University of Michigan), Gerald E. McClearn (Pennsylvania State University), Mark A. McDaniel (University of New Mexico, now at Washington University), Joan M. McDowd (University of Kansas), Peter C. M. Molenaar (University of Amsterdam, The Netherlands; now at Pennsylvania State University), John R. Nesselroade (University of Virginia), Richard E. Nisbett (University of Michigan), Denise C. Park (University of Illinois, Urbana-Champaign, now at University of Texas, Dallas), Andrea M. Piccinin (Pennsylvania State University, now at Oregon State University), Patrick M. A. Rabbitt (Oxford University, England), Naftali Raz (Wayne State University), Patricia Reuter-Lorenz (University of Michigan), Chandra A. Reynolds (University of California, Riverside), Willard L. Rodgers (University of Michigan), Timothy A. Salthouse (University of Virginia), Mary Sano (Columbia University), K. Warner Schaie (Pennsylvania State University), Martin Sliwinski (Syracuse University), Brent J. Small (University of South Florida), Avron Spiro III (Veterans Administration, Boston), Valgeir Thorvaldsson (Gteborg University, Sweden), Paul Verhaeghen (Syracuse University, now at Georgia Institute of Technology), Keith F. Widaman (University of California, Davis), Keith Whitfield (Pennsylvania State University, now at Duke University), Robert J. Willis (University of Michigan), Sherry L. Willis (Pennsylvania State University), Robert S. Wilson (Rush University Medical Center), Linda A. Wray (Pennsylvania State University), and Elizabeth M. Zelinski (University of Southern California). As noted, virtually all of these participants contributed a chapter to the present volume, and of course, we have added several contributors.

We acknowledge the contributions of all these participants at the ICFCAR, plus the many [Page xiii]other people who helped make the conference a success, either through their participation or support. This included representatives of the Cognitive Aging programs at the NIA (Jeffrey Elias and Molly Wagster) as well as the Office of Director of the Behavioral and Social Sciences Branch (specifically, Ron Abeles) of the NIA. A number of additional members the NIA Behavioral and Social Sciences Branch staff were invited to attend, as well.

We are also grateful to our respective collegiate administrators, Ray Coward, Dean of the College of Human Development (now Provost at Utah State University); Susan Welch, Dean of the College of the Liberal Arts, Pennsylvania State University; and Mark Hayward, who was then director of the Social Science Research Institute at Pennsylvania State University, the three of whom provided generous support for the conference. We wish to acknowledge our close colleagues at Pennsylvania State University, who served as members of our local organizing committee and who helped introduce speakers and kept the flow of the conference running smoothly, specifically, David M. Almeida, Paul Eslinger, Andrea M. Piccinin, K. Warner Schaie, Keith Whitfield, Sherry L. Willis, and Linda A. Wray. Finally, we wish to thank the Associate Editors and many reviewers of contributions to this handbook for their insightful comments and challenging questions, including Jason C. Allaire, North Carolina State University, Department of Psychology; John Dunlosky, Kent State University, Department of Psychology; Andrea Halpern, Bucknell University, Department of Psychology; Lesa Hoffman, University of Nebraska, Department of Psychology; Diane Howieson, Oregon Health and Science University, Layton Aging and Alzheimer's Disease Center; Susan Kemper, University of Kansas, Department of Psychology; Matthias Kliegel, University of Zurich (Switzerland), Department of Psychology; Donna La Voie, Saint Louis University, Department of Psychology; Cindy A. Lustig, University of Michigan, Department of Psychology; Mike Martin, University of Zurich (Switzerland), Department of Psychology; Ryan J. McCammon, University of Michigan (Ann Arbor), Department of Psychiatry; Gerald E. McClearn, Pennsylvania State University, Department of Biobehavioral Health; Deb McGinnis, Oakland University, Department of Psychology; Jacqueline Mogle, Syracuse University, Department of Psychology; Chandra Reynolds, University of California, Riverside, Department of Psychology; Robert S. Stawski, Pennsylvania State University, Department of Human Development and Family Studies.

The ICFCAR led to the organization of additional activities, some of which are also represented in the present volume. Symposia titled “The Antecedents and Consequences of Cognitive Aging” (co-organized by Duane F. Alwin and Scott M. Hofer) and “Integrative Analysis of Longitudinal Studies: Accounting for Health in Aging-Related Processes” and “Innovative Methods for Describing Developmental Change” (organized by Scott M. Hofer) based on some of the results of this conference, were held at the 59th annual meetings of the Gerontological Society of America, October 2006, in Dallas, Texas. In addition, several of the papers developed for the conference were presented at the annual Cognitive Aging Conference held in Atlanta, Georgia, April 20–23, 2006.

In the present volume, we have put together a set of contributions that span the range of disciplines working on issues related to cognitive aging. We hope this collection will not only contribute to the future of cognitive aging research but also help build a multidisciplinary agenda that will stimulate the improvement of research into the complex set of factors that produce cognitive change in midlife and older age.