Behavioral Research at NIA

From its inception in 1974, the National Institute on Aging (NIA) has made behavioral and social research an integral part of the Institute’s effort to understand and improve the second half of life. The importance of behavioral and social research stems from the fact that social and psychological, as well as physical and biomedical factors are linked to the health and well-being of individuals and of our society as a whole. (See article on page 1 of this issue.)

It is gratifying that today’s older generation of Americans is healthier and wealthier than any before. Recently, we have been heartened by important new demographic research showing that the rate of disability among older people including cognitive dysfunction and the inability to perform everyday activities like bathing or using the telephone- is declining. Further analyses are needed to determine more precisely how medical and psychosocial interventions and improved economic conditions may have contributed to the health of the elderly. But these recent demographic findings send us a clear and encouraging message: The aging of the population does not have to result in a less healthy and more frail population.

Appropriate interventions can make a difference in the quality of life for older people and their families. At the same time, by keeping frailty and illness at bay, these interventions will give us an opportunity to slow the growth in health care costs expected with the rapid aging of the population.

To help achieve these goals, the NIA’s behavioral and social research agenda has established three objectives:

1. To understand the aging process and how biological aging interacts with psychological and social aging within a changing environment.

2. To understand the place, potential, and problems of older people in society, including the community, the family, the workplace, and other social institutions.

3. To develop a knowledge base for prolonging the productive and heal thy functioning of the middle years of life by preventing. reversing, or slowing the progress of decrements associated with old age, such as chronic ill health, memory loss, economic deprivation. and withdrawal from active participation in social and economic roles.

At its most basic, research supported and conducted by the NIA on adult cognition attempts to link behavioral changes in aging to the brain mechanisms in which they are grounded. The search for clues to understanding the human brain-behavior relationship seeks to define how these relationships are affected by the aging process and how they impact the detection, early diagnosis, and ultimate treatment of pathological cognitive changes that occur with aging, such as those associated with Alzheimer’s disease. We also look to these studies to provide explanations for the great individual differences that exist in cognition among people in late life.

New Developments, Exciting Times

This has been a particularly exciting year in the field, as there have been several important aging research-related developments. First, psychologists investigating learning and memory processes during aging have begun to integrate PET imaging and functional MRI into their studies. Now, particular areas of the brain can be linked to very specific types of learning and memory. In addition, findings from studies of older people are beginning to converge with those reported in the animal literature, suggesting the importance of the dorsolateral prefrontal lobe in working memory, an area that appears compromised with aging. Important also are studies indicating that generalized neuron loss is not an inevitable consequence of healthy aging; there are many brain areas that are spared.

In other studies, hippocampal and related medial temporal lobe sites have been more precisely identified in terms of their role in “encoding” or “acquisition” of new information and in relation to memory problems in aging. Of especially great interest has been research about the mechanisms of synaptic plasticity in the aging hippocampus. These studies have given us new information on how we might prevent or retard age-related memory declines through the use of neural growth factors or mental exercises or stimulation that can enhance synaptic connections.

A number of basic behavioral and psychological studies are under way to examine individual differences in cognitive aging. A recurrent theme in all research on aging is the heterogeneity of the older population, cognition being no exception. We now know that several variables contribute to age differences in cognitive function, such as birth cohort, motivational factors, affect, experience, self efficacy, fatigue, strategy differences, and metacognition. Recent findings indicate that health status and genetic differences may play a significant role, especially for women.

The Five-Factor Model of Personality, a model of trait structure elaborated by NIA intramural scientists, has allowed rapid progress in understanding the origins, stability, and predictive use of personality traits. By now, the personality instrument developed by the Gerontology Research Center team has been translated into 20 languages and will be used to compare cross-sectional studies of age differences in personality in different countries and cultures. U.S. samples, for instance, show that individuals in their later teens and early 20s differ systematically from adults over age 30 (they are more highly emotional and less well socialized). By contrast, between the 30s and 70s, no personality differences are observed. If data from other countries show the same cross-sectional patterns, this might suggest some universal and intrinsic process of personality development.

New Directions

While these research areas continue to mature, behavioral research is moving in some intriguing new directions. With several decades of concentrated study on understanding the brain, cognition, and personality, we are now ready to apply what we know to the everyday lives of older adults. In 1993, the Institute started six Edward R. Roybal Centers for Research on Applied Gerontology. Several of the centers’ projects are designed to integrate older people into the growing use of technology, such as computers and automated teller machines. The centers will test ways to make new technologies adapt to older adults, and vice versa. Other center projects aim at reducing the rate of accidents among older drivers and overcoming the resistance of some older people to exercise programs.

In addition, in the past year, NIA has collaborated with the National Institute of Nursing Research to initiate a multi-site trial of cognitive interventions to help older people maintain independence. This unique study will investigate interventions to improve cognitive functioning in healthy community samples and will assess their impact on everyday functioning and health. Now in the study design phase, the project should begin recruiting older adults later this year.

In September 1996, in an effort to broaden understanding of cognitive changes with aging, the Institute sponsored a workshop examining how social processes influence cognition. Most research on cognition in later life has concentrated on context-free processes, such as speed of processing and working memory changes. This approach, however, has ignored adaptive changes in cognitive skills such as expertise, which may greatly compensate for cognitive deficits, Studies are now under way to examine, among other issues, how social cognition affects decision-making and how social interaction and communication with others may affect health and well-being.

Longitudinal, Genetic Studies

Along these lines, two nationally representative, longitudinal studies sponsored by NIA are expected to provide new insights into aging, health, and retirement. The Health and Retirement Study and the survey of Asset and Health Dynamics Among the Oldest-Old are exploring new ways to measure cognitive, emotional, and social aspects of the lives of people 51 and older. The studies are testing a number of instruments for assessing functional status, memory, crystallized intelligence, and depression. Researchers are now looking at the initial waves of the survey and should be able to report findings in these areas soon.

Rapid changes in all areas of genetics and the availability of transgenic models and gene substitution and knockout techniques are having a great impact on research into the biology of aging. At the cutting edge of behavioral research are new efforts to consider gerontological questions in behavioral genetics.

At the May 1996 Behavior Genetics Association convention. NIA organized a symposium to develop a research agenda, identify conceptual and methodological barriers to research on behavioral genetics and aging, foster collaboration in research in this area, and encourage research and research training grant applications. The Institute is planning to formally announce a program initiative in this area within the coming year.

Behavioral genetics researchers only now are beginning to appreciate the implications for understanding higher-order behaviors like cognitive function and complex traits like personality. There is recent evidence of genetic markers alleles of the D, dopamine-receptor gene (D,DR)-for certain normal personality traits. Studies in a variety of populations, including groups of twins and the NIA’s long-standing Baltimore Longitudinal Study of Aging, are now being conducted to look at the relation between other central nervous system receptor alleles and personality traits and other psychosocial variables. These studies and others may provide clues for the role of the dopamine system and its influence on behavior. Ultimately, these studies will illuminate the broader genetic basis of normal variations in cognitive functioning and personality.

These types of advances cannot come quickly enough. We know, of course, that cognitive and physical declines increase markedly with advanced age. The number of very old people, age 85 and older, is expected to reach at least 7 million over the next 20 years, and that number will soar to possibly 27 million or higher by 2050. Without new and effective interventions to improve healthy life expectancy for large and growing numbers of older people- most especially the very old-the pressures on families and on formal and informal long-term care systems will be extreme. Behavioral research will play a critical role in managing the challenges that lie ahead .