Seed Grant Recepients 2000-2001

Faculty Seed Grants

THE AGING IMMUNE SYSTEM: ANTIBODY REPERTOIRE AND AUTOANTIBODY RESPONSES

Dr. Roberta Attanasio, D.Sc., Department of Biology, Georgia State University

The geriatric years of life are usually considered to be characterized by a decline in immune functions, resulting in increased susceptibility to infectious diseases as well other pathologies that are controlled by a well-functioning immune system. However, the changes observed in the immune responses of elderly individuals may be the result of a remodeling or reconfiguration of the immune system, in turn resulting from the adaptation to changing developmental stages and interactions of different organ systems. To understand how to best protect the geriatric population from challenges that require the presence of an efficient immune system, it is necessary to define the immune system-related changes occurring in old age in absence of confounding factors represented by differences in life-style, diet, exercise habits, stress levels, alcohol consumption, medical history, drug use or abuse and so on. For this reason, we use a well-defined animal model consisting of healthy baboons of age encompassing the entire life-span of this animal species. Because of their genetic and physiological similarities to humans, the use of baboons provides results that can be easily extrapolated to humans. Using the baboon model, we have recently demonstrated that autoantibody production increases with increasing age. Such increase in autoantibody production occurs in absence of a corresponding increase in markers of dysregulation, thus indicating that autoantibody production is not associated with detectable pathological conditions. As a first step to understand the mechanisms that lead to increased production of autoantibodies in old animals, we propose to define and compare young and old animals on the basis of immunoglobulin variable region gene usage. Results from these studies will be used to design further experiments to identify the regulatory processes involved in the shaping of the senescent antibody repertoire.

REPORTING OF FUNCTIONAL OUTCOMES INTENDED TO ACTIVATE BEHAVIORAL CHANGE IN OLDER ADULTS

M. Elaine Cress, Ph.D., Exercise Science, University of Georgia

Remaining functionally independent to the end of life is a high priority for older adults. This priority might motivate older adults to implement positive health habits that can preserve their functional independence. The goal of this project is to develop and implement a system for motivating older adults to make life style changes. We call this system Reporting Intended to Activate or RITA. The report will integrate their current lifestyle choices and exercise preferences with objective data from a physical function and peripheral vascular disease assessment. We will implement this reporting in a population that is "at risk" for disability through peripheral vascular disease. The specific aims of this project are to 1) develop and assess an individually tailored method of functional assessment based on personal health habits and preferences; 2) Determine the association of blood flow limitation to physical functional performance; 3) Incorporate the underlying peripheral vascular pathology into the RITA report. To achieve these aims we will ask 30 older adult volunteers to complete a health questionnaire. We will test them for peripheral vascular disease using standard medical procedures including pulse volume recording and arm ankle pressure recording, and we will assess their functional ability using the Continuous Scale Physical Functional Performance Test (CS-PFP). The CS-PFP yields a total score and separate scores for 5 domains (upper and lower body strength, flexibility, balance and coordination, endurance) of functional ability. Participants will report their readiness for behavioral change following receipt of the standard medical report and then again following the RITA report. A community health nurse will conduct focus groups to optimize the reporting system at the individual level and to the health care profession.

SOCIAL NETWORKS AND EXPLORATORY BEHAVIOR OF AGED VS. YOUNGER CAPUCHIN MONKEYS

Dr. Dorothy M. Fragazy, Psychology Department, University of Georgia

Nonhuman primate models of aging provide opportunities for basic prospective research in gerontology. This project will explore the usefulness of capuchin monkeys for behavioral gerontological research, using both cross-sectional and longitudinal comparisons. Capuchins are not now used for this purpose, although the genus is common in biomedical and behavioral research. This initial study will focus on the relationships among social networks, exploratory behavior, and age in adult female capuchins. Three striking aspects of capuchins' life history are their longevity (50+ years), their large brains relative to body size, and their manipulative and problem-solving propensities, including the frequent spontaneous use of tools (as seen great apes, but in no other genus of monkeys). These characteristics jointly make capuchins a very interesting genus in which to conduct behavioral gerontological research. I propose to evaluate the behavior of eighteen female capuchins in three age groups (young, mature, and old; 6 females per age group) living in two large captive breeding groups housed at LABS (a commercial entity) in Yemassee, South Carolina We will code social interactions, social spacing, and exploratory (object-directed) activity of these monkeys in their home enclosures during undisturbed conditions, and following the introduction of objects intended to provoke social interaction and exploration. Additionally, we will compare the new data on exploration from several of these individuals to their own records from a study of manual activity conducted 13 years ago. I intend that these data will serve to document the value of continued research with these monkeys in gerontological research (in short, as pilot data when seeking further funding).

CHANGING PERCEPTIONS OF UNIVERSITY STUDENTS THROUGH INTERGENERATIONAL ACTIVITIES WITH ELDERLY RESIDENTS IN LONG TERM CARE

Mary Lou Bryant Frank, Ph.D., Department of Psychology/Sociology, North Georgia College and State University; Jill Hayes, Ph.D., RN, C

The elderly population is the fastest growing segment of the United States (U.S.). In 1900 adults 65+ years old accounted for 4% of the population of the U.S. In 1996 this cohort equaled 33.9 million or 12.8% of the population. By the year 2030 it is predicted that the age group 65 + years will equal 69 million. The need for programming aimed at maximizing the quality of life of the older population and creating positive intergenerational relationships is currently receiving more attention than ever before in this country. According to Hooyman and Kiyak (1999) intergenerational programs maximize the non-material resources older adults possess and significantly contribute to their quality of life and role in society. North Georgia College & State University (NGCSU), a liberal arts university in Northeast Georgia, recently partnered with a local nursing home to provide optimal clinical experiences for students from six academic departments and a site for faculty research and practice. In addition to the development of meaningful clinical experiences for students relative to their program of study, the chair of the committee coordinating partnership activities proposes to evaluate student attitudes towards elderly adults residing in long term care and any change in these attitudes following involvement in this partnership, utilizing the Children's Perception of Aging and Elderly Inventory (Aday, Aday, Arnold & Bendix, 1996). Findings will be utilized to increase involvement in the partnership by various academic departments on campus and to strengthen application for external funding to expand the partnership project.

ASSESSMENT OF STAGES OF CHANGE FOR CANCER PREVENTION AMONG GEORGIA SENIORS

James L. Hargrove, Ph.D., Department of Foods and Nutrition, University of Georgia

The hypothesis of this proposal is that the need for improved health promotion is particularly great among older Georgians due to limitations in knowledge, motivation to change, and ability to change diet or activity patterns. This proposal will survey groups of seniors (55 and older) to identify their current knowledge and behavior concerning prevention of specific cancers (colon, prostate, and mammary). It will also assess readiness for change as a first step in developing appropriate educational tools. An interactive, anonymous survey based on dietary applications of the Stages of Change behavioral model will be conducted at local residence centers and at sites identified through the College of Family and Consumer Sciences outreach programs. The survey will be conducted in workshop format employing the Perception Analyzer System (PAS). The PAS is a portable, computer-based device that allows participants to use handsets to respond to questions presented on a projection screen. The handsets relay data to the computer, which immediately graphs the responses and presents the outcomes so that the instructor may discuss misconceptions and provide follow-up with no delay. Analysis of the data allows the investigator to identify deficits relative to current knowledge, and to design appropriate educational material for specific audiences. The survey to be developed will include questions designed to indicate the distribution of stages of change that characterizes representative audiences in NE Georgia. In addition, it will include questions that are intended to facilitate discussion of health benefits for dietary choices and activity patterns recommended by the American Cancer Society. This information will be used to create pictorial, written, and web-based educational modules concerning cancer prevention that can be used by cancer educators as components of workshops and presentations at local sites. A PowerPoint presentation, an interactive, simulation-based presentation, and accompanying hand-outs will be developed based on the results of the PAS study. These materials will be made available to educators free of charge on a web site devoted to nutrition education for the elderly. The project described here is intended to provide pilot data for a cancer education grant that will subsequently be submitted to the National Cancer Institute and other national agencies.

NOAH NET: NUTRITION FOR OLDER ADULTS HEALTH

Mary Ann Johnson, Ph.D., Department of Foods and Nutrition, University of Georgia; Joan G. Fischer, Ph.D.

Nutrition is important in the prevention, management and clinical outcomes of numerous diseases including cardiovascular disease, hypertension, high blood cholesterol, diabetes, obesity, osteoporosis, and some cancers. Community-based nutrition education programs are a valuable way to reduce the risk of chronic disease. However, there is a critical shortage of nutrition education materials targeted toward older adults with low income and low literacy skills. Thus, our goal is to develop a web site directed toward nutrition, health, and gerontology professionals who provide nutrition education programs for elders with limited resources. The target group of professionals is employed by Area Agencies on Aging and the Cooperative Extension Service. The target population for nutrition education is low income, low literacy older adults participating in Elderly Nutrition Programs through Area Agencies on Aging.

TOWER RECREATION AND INDEPENDENT LIVING PROJECT

Douglas A. Kleiber, Ph.D., Department of Recreation and Leisure Studies, University of Georgia

The purpose of the current proposal is to create an activity program in a senior housing setting (Denny Tower in Athens, Georgia) which will attract residents into patterns of involvement that are physically beneficial while being enjoyable and likely to be maintained, thereby improving prospects for good health and reducing dependence on external services. A pre-test post-test quasi-experimental design will be used to assess the effects of various patterns of involvement with gardening, music appreciation and dance, pet care and autobiographical writing on physical functioning and reliance on social assistance. The outcome of this seed grant project will facilitate development of the overall research program.

ASSESSING THE DYNAMICS OF FINANCIAL SECURITY AND HEALTH STATUS OF ETHNIC MINORITY ELDERS WITH CHRONIC HEALTH CONDITIONS

Jinkook Lee, Ph.D., Housing and Consumer Economics, University of Georgia

Although financial security of the elderly with chronic health conditions has been cited as an important issue, only limited research attention has been devoted to this topic. A comprehensive multi-disciplinary study that integrates consumer finance literature with health care literature is much needed to understand the dynamics of health status and financial security. Furthermore, minority elders have been repeatedly identified as having poorer financial and physical health than Caucasian elders and thus is a population deserving particular research attention. This project is a starting point for this effort. Using the Asset and Health Dynamics of the Oldest Old (AHEAD) survey commissioned by the National Institute on Aging, in this study the principal investigator will portray a full profile of the financial security of minority elders with chronic illnesses. The outcome of this project will serve as a valuable baseline information, providing answers to whether minority elders are indeed worse-off than Caucasian elders, considering not only their financial assets and reported health status, but also the formal and informal health care they receive. The results of this project will also enable the principal investigator to fully develop a comprehensive research proposal to disentangle the dynamics of health and financial security.

DEVELOPMENT OF A TOOL FOR ASSESSING PESTICIDE EXPOSURE AS A FACTOR IN NEUROLOGICAL DISORDERS OF THE ELDERLY

David L. MacIntosh, Sc.D., Environmental Science, University of Georgia

Parkinson's disease (PD) is a disorder of the central nervous system that affects 1,000,000 - 1,500,00 people in the United States. The etiology of PD is unknown although it is suspected to be the product of interactions between genetic and environmental factors. Rural living, well-water consumption, and exposure to pesticides have emerged as potential risk factors from a number of studies, although methodological difficulties related to case definition, selection of controls, and assessment of environmental exposures pose formidable challenges to improved understanding of the exposure-disease relationship. The goal of the proposed research is to build upon previous work and develop a simple and reliable questionnaire for assessing exposure to neurotoxic insecticides suspected to be etiologic factors in PD. If validated with exposure measurements, then the questionnaire could be used in a larger, extramurally supported study of residential exposure to insecticides and neurological diseases of the aged suchas PD. The research plan is designed to determine if the questionnaire can predict non-dietary exposure to three ubiquitous residential-use organophosphorous insecticides: use of chlorpyrifos, diazinon, and malathion. Exposure measurements of the chemicals in settled dust and indoor air of participating residences will be used as the gold standard against which the questionnaire responses will be compared. Moderate to strong associations between survey responses and environmental measurements will indicate the questionnaire is predictive of actual exposure; weak associations will indicate the questionnaire has little predictive power. The study will begin at the time of award and be completed in time for presentation of findings at the Gerontology Center symposium in April 2001.

ASSESSING ELDERS FOR PERIPHERAL ARTERIAL VASCULAR DISEASE

Kevin McCully, Ph.D., Exercise Science, University of Georgia

Encouraging community participation in preventative health is becoming increasingly important. Cardiovascular disease is a major health risk and is very amendable to preventative health care. The goal of this project is to develop an assessment program for the elderly for common form of cardiovascular disease: peripheral vascular disease (PVD). The specific aims are to: 1) test a representative sample of older adults with a standard arterial vascular assessment, 2) develop appropriate pre and post test educational materials, and 3) evaluate an optical spectroscopy assessment of vascular function in older adults. To achieve these aims we will recruit and test 30 representative older adults. All testing will be noninvasive and most older adults in stable medical condition will be eligible. Study subjects will undergo a standard vascular test protocol, along with a short questionnaire of cardiovascular risk factors. The test will include pulse volume (PVR) recordings of the left and right ankles and right arm. Systolic pressure at the left and right ankle and right arm will be measured with an 8 mHz Doppler probe. The ankle to arm pressure index (AAI) will be used as the indicator of vascular disease. The PVR results will be a qualitative check on the AAI results. Commercial educational materials on PVD will be provided along with supplemental material specific to our test and test results. An optical spectroscopy device will be placed on the calf muscles and changes in oxygen saturation will be measured after short muscle contractions. We will compare the rate of oxygen return after exercise with the AAI. This project is the first step towards a fundable program in gerontological research. It will enable the PI to submit a competitive proposal to NIA on the evaluation of vascular disease, and it will serve as part of larger effort to set up a UGA-based collaborative project in sustaining independence for older adults.

RAPID SCREENING OF THE METHUSELAH PROTEIN -- A PUTATIVE LONGEVITY ASSURANCE GENE -- IN NATURAL POPULATIONS OF THE FRUIT FLY, D. MELANOGASTER

Daniel Promislow, Ph.D., Department of Genetics, University of Georgia

In the past few years, investigators have redoubled their efforts to identify genes associated with rates of aging. Thus far, only a handful of genes have been identified. In Drosophila, a popular model organism for the study of aging, the most hopeful candidate so far is methuselah (mth). Flies that express mth have shortened life span and reduced resistance to stress (Lin et al. 1998). However, no one has yet been able to determine whether variation in longevity in natural populations is actually correlated with expression of this or any other gene. This correlation would provide a critical piece of evidence for mth as an 'aging gene'. The following study aims to test for this correlation. We plan to apply a rapid new method for generating monoclonal antibodies to the Methuselah protein family using synthetic peptides as immunogens and crude protein extracts as antigens. To carry this out, one need only know the sequence of the protein of interest. We will generate synthetic Multiple Antigenic Peptides (MAPs) that are derived from the two terminal ends of the Mth protein sequence. These MAPs will then be injected into mice as antigens, to which mice will make antibodies. We will then isolate cell lines from these mice which produce antibodies that react with the Methuselah protein. Once we have obtained these antibodies, we will be able to measure Mth levels in strains of fruit flies derived from nature that differ in longevity. These data on their own will be of great interest to those interested in the genetics of aging, and will place us in an excellent position to obtain further funding.

APHASIA AND ATTENTION: THE ROLE OF BINDING IN LANGUAGE AFTER STROKE

Rebecca J. Shisler, Ph.D., Communication Sciences and Disorders, University of Georgia

The over-50 population is expected to be the fastest growing U.S. age group by the year 2000 (National Stroke Association, 2000). Research has shown that for each decade after age 55, the risk of stroke doubles. Therefore, as individuals age, there is an increased risk of stroke and subsequent disabilities. One such disability is aphasia, a language deficit that can occur following a left hemisphere stroke. Deficits in attention may also occur after stroke, causing older individuals related difficulties while attempting rehabilitation. In fact, existing research consistently finds that attention influences specific aspects of our cognitive process, such as language (Murray, 2000). One such problem studied in the past is the relationship attention between the ability of a patient to pull together identification and localization information, called binding. Shisler, Baylis, and Gore (2000) found that in older individuals after right hemisphere stroke, a deficit in binding was observed and patients were unable to attend to two auditory items presented simultaneously. The purpose of this study is to investigate if individuals with left hemisphere stroke and aphasia have a decrement in performance on the same auditory attention task that requires binding. By investigating the role of attention and binding in aphasia, a further understanding of the underlying deficits that contribute to aphasia may emerge.

Student Seed Grants

ACCELERATED AGE-RELATED DECLINE OF SENSORY-PERCEPTUAL PROCESSING IN HEALTHY, ELDERLY, FIRST-DEGREE RELATIVES OF PERSONS WITH SCHIZOPHRENIA

Jeffrey S. Bedwell, Psychology Department, University of Georgia

Research focusing on individuals with schizophrenia has noted that a subgroup of these individuals evidence an accelerated age-related decline in general cognitive performance 1, particularly on tasks that utilize sensory-perceptual processing 2. However, relatively few studies have examined late-aging effects in this population. An alternative population to examine is healthy first-degree relatives of persons with schizophrenia (HRPS), which is advantageous because unique characteristics found in these individuals may offer insight into genetic expression in schizophrenia without the confounds of neuroleptic exposure, hospitalization, and active symptom effects. 3,4 While there appears to be an absence of published literature examining accelerated age-related cognitive decline in HRPS, recent unpublished research suggests such a decline in elderly relatives on tasks reflecting both sensory-perceptual processing and attention (K.H. Nuechterlein, personal communication, August 11, 2000). This study proposes three central aims: 1) To investigate the effect of old age on sensory-perceptual processing and attention; 2) To investigate whether sensory-perceptual processing ability differs between the HRPS group and persons without a familial history of schizophrenia spectrum disorders (collapsing for age); and 3) To investigate whether the aging effect on sensory-perceptual processing is accelerated in the HRPS group. This investigation will entail the utilization of three computerized measures of sensory-perceptual processing and attention � a backward masking task, the Span of Apprehension test, and the Continuous Performance Test. Two summary measures will be derived to individuate primary effects of sensory-perceptual processing from attention on performance. The investigators hypothesize that: 1) test conditions that primarily reflect sensory-perceptual processing will evidence accelerated performance decline during old age in the HRPS group exclusively; 2) that performance on both sensory-perceptual processing and attention measures will decline over old age for both experimental groups; and 3) that the HRPS group will display impaired performance on tasks that primarily reflect sensory-perceptual processing (collapsing for age).

TRANSITIONS IN CAREGIVING

William Keith Dooley, Psychology Department, University of Georgia

A study is proposed to examine the impact of transitions in the caregiving relationship on caregiver well-being. Family caregiving to community residing elders is conceptualized as a career involving stages of caring behaviors and transitions between stages. The proposed study will focus on transitions that occur in the later stages of the caregiving career: placement of the elderly care recipient in an institution, death of the care recipient, and cessation of caregiving for logistical/personal reasons. Caregivers recently attrited from an ongoing longitudinal study of late life family caregiving relationships will be interviewed upon placement or death of their elderly care recipients. The study will examine elements of the caregiving relationship that have not received attention in the current literature. We expect that the transition experience will differ for caregivers of demented and non-demented elders; furthermore, we expect that pre-illness caregiver-care recipient relationship will explain a significant proportion of the variance in caregivers' reactions to these transitions. It is expected that the information collected will add to the existing literature by providing a more thorough conceptualization of the trajectory of long-term family caregiving relationships.

AGING AND THE LEARNING OF COMPUTER SKILLS

Dianne Ford Lawton, Ed.S., M.A., Department of Curriculum and Instruction, Valdosta State University

At the threshold of the twenty-first century, two trends are converging: the U. S. population is growing older, and technology is changing the way society receives services and performs tasks. Senior adults must have the necessary skills to use technology if it is to benefit them. Older adults who acquire basic computer skills and knowledge of the Internet are then able to broaden their world through greater educational and social opportunities. Since most older adults did not learn to use computers in school, it is important that they have access to computer instruction that is designed specifically for them. Analysis of a needs assessment conducted in the spring of 1999 among a representative sample of 54 senior adults between the ages of 55 and 85 indicated that this population had the greatest performance discrepancy in the area of computer competencies (Lawton, 1999). Of the senior adults surveyed, more than 50% indicated that they would like to acquire or improve their computer skills. There were adequate data from the needs assessment to support a project to address the need for computer literacy among senior adults. A pilot workshop using an instructional design based on the principles of andragogy was conducted in the spring of 2000. Findings from the data analysis of this pilot project indicated that the participants increased their computer skills and their confidence in computer use as a result of the instruction. This project addresses the problem of the lack of computer skills and confidence in computer use among senior adults, ages 55 and above. The focus of the project will be on the need to design instructional materials and to develop instructional strategies that are theoretically grounded in the principles of andragogy and take into consideration the cognitive changes associated with aging.

THE EFFECT OF WARNINGS ON FALSE MEMORIES IN YOUNG AND OLDER ADULTS

David P. McCabe, B.A., Psychology Department, Georgia Institute of Technology

In the Deese-Roediger-McDermott converging associates paradigm, false alarms to a non-presented lure word (e.g., sleep) are produced after participants listen to a list of related words (e.g., bed, rest, awake, tired, etc.). This paradigm will be useful in assessing the ability of young and older adults to avoid false memories. In the proposed experiment, young and older participants will either be unwarned about the DRM false memory effect (No Warning; NW), warned about the effect before the recognition test (Retrieval Warning; RW), or warned before study (Study Warning; SW). False recognition in the warning groups is expected to be inversely proportionate to amount of processing resources available (as indexed by measures of speed and working memory), which typically decline with increasing age.

THE EFFECT OF STRENGTH AND POWER TRAINING ON PHYSICAL FUNCTION IN OLDER ADULTS

Tanya Miszko, M.S., Exercise Science, University of Georgia

The ability of an older adult to perform daily tasks may be influenced by the age-associated declines in muscle strength, power, and aerobic capacity. Due to the declines in aerobic capacity, older adults may rely on their anaerobic capacity to complete daily tasks. Strength training interventions have been successfully performed on older adults and demonstrated improvements in muscle strength, power, and selected functional measures. However, power training has primarily been conducted on young adults and athletes. Therefore, the primary purpose of this study is to examine the effect of a 20-week strength and power training program on physical function in older adults. This study is a randomized controlled trial conducted on forty-two 65-85 year old men and women who do not exceed a threshold for lower extremity power (LEP). Subjects will be randomly assigned to either a control (C; n=14) or strength group (ST; n=28). The ST group will meet 3 days/week for 12 weeks then will be randomly assigned to a ST (n=14) or power training (PT; n=14) group 3 days/week for 8 weeks. Subjects in the control group will continue usual activity throughout the duration of the study, however will not partake in any new exercise program, jog/run, or strength training. The primary outcome measure is the Continuous Scale Physical Functional Performance test (CS-PFP). Secondary outcome measures include muscle strength, lower extremity power (LEP), and anaerobic power. All outcome variables will be evaluated at baseline and at weeks 12 and 20. A one-way ANCOVA, with the pre-test as the covariate, will be used to analyze the effect of the training intervention(s) on physical function, lower extremity power, leg strength, and anaerobic power. Multiple regression will be performed to examine the relationship between function, anaerobic power, and strength. An alpha level of 0.05 will be required to establish significance.

CHANGES IN THE FOVEAL AVASCULAR ZONE THROUGHOUT THE LIFESPAN

Kimberly A. Morris, M.S., Psychology Department, University of Georgia

Many age-related eye diseases that lead to blindness, such as age-related macular degeneration (AMD) have a direct effect on the center part of the retina, the macula. Differences in the macula exist between individuals and some of these differences can indicate a predisposition for various diseases. Therefore, it is important to study individual differences in this area of the eye to determine what factors can be used to predict disease. At this time however, little is known about individual differences in the normal, aging retina. This study proposes to study individual differences in retinal vasculature in people across the lifespan, specifically the area in the macula that does not contain vessels called the foveal avascular zone (FAZ). Participants will undergo a battery of tests to determine which factors correlate with the size of the FAZ (e.g., macular pigment width, sex, iris color), and to determine how FAZ size influences visual performance.

THE RELATIONSHIP OF DAILY WALKING TO PHYSICAL FUNCTION

John K. Petrella, M.Ed., Exercise Science, University of Georgia

Prevention of physical disability is a priority of aging research as nearly 40% of individuals 65 years and older exhibit limitations in the ability to carry out daily activities. Identifying factors that influence the impact of functional limitations on disability can provide valuable information for understanding the pathway to disability. Individuals with functional decrements such as using a cane may unconsciously modify strategies to perform a task. These 'modifiers' may form a subset of adults in an early stage of limitation who may be at high risk of progressing to disability. Functional limitation usually occurs first in the area of ambulation. Thus, two possible indicators of diminished function may be self-reported modification of the manner in which an ADL is performed, as well as measures of mobility. The ability to test and predict those at the threshold of limitation or at risk for disability would be invaluable in preventing the physical disability associated with aging. Most clinicians agree that prediction and prevention of medical problems is the best method of optimizing health and reducing health care costs of older adults. While walking may reduce the risk of all cause mortality, its ability to improve physical function has yet to be examined. The purpose of this study is to examine the relationship between the objective measure of walking behavior and self-report physical function, self-report physical activity, dynamic balance, and performance-based physical function. We hypothesize that individuals who do not report the use of modification strategies to function will take more total steps per day than those who modify their ADL's. Additionally, individuals who report no modification will have greater dynamic balance and performance-based function than those who report modification. Early detection of this pre-limitation group by objective measures could provide an individual with timely intervention and the motivation to implement them before moving into disability.

MATERNAL AGE EFFECTS ON NONDISJUNCTION IN FRUIT FLIES

Nicholas K. Priest, Department of Genetics, University of Georgia

Chromosomal nondisjunction, the failure of paired chromosomes to pass to different cells during meiosis, is a significant medical problem for reproductively active older women. Nondisjunction at chromosome 21 causes Down syndrome, the most frequent genetic cause of mental retardation. While the incidence of Down syndrome for young women (age 20) is 1/2,300 live births, the incidence for older women (age 45) approaches 1/46. Though there has been intensive interest in the factors that cause age induced Down syndrome, we do not understand why or how maternal age influences nondisjunction. One problem with studying Down syndrome in humans is that there does not appear to be any family history of Down syndrome. This means that it is doubtful that the typical human pedigree analysis of the phenomenon will help us understand the genetic factors that influence nondisjunction in older women. Since the discovery of nondisjunction in fruit flies by Bridges in 1916, there have been significant advances in our understanding of the genetic basis of nondisjunction in humans and fruit flies. These advances indicate that the mechanism of nondisjunction in humans and fruit flies is remarkably similar. However, though maternal age is the most important factor regulating non-disjunction in humans, the effect of maternal age on nondisjunction in fruit flies remains unknown. In the study proposed here, I will use large-scale demographic methods and genetics to determine how maternal age alters nondisjunction in the fruit fly, Drosophila melanogaster. The rational for the experiment is simple: If we can show that maternal age influences nondisjunction in fruit flies, we can determine how it happens in fruit flies, which might help us identify how age induced nondisjunction occurs in humans.

AN EXAMINATION OF PROCESSING RESOURCE AND KNOWLEDGE STRUCTURE CONTRIBUTIONS

Chuck L. Robertson, M.S., Department of Psychology, Georgia Institute of Technology

The idea that older adults are able to compensate for losses in fluid abilities like speed of processing with concrete knowledge abilities like vocabulary or general knowledge has provided mixed results. People of all ages benefit in task performance from larger amounts of speed and knowledge in simple verbal tasks such as word fluency, solving anagrams, and the making words task (Salthouse, 1993). In addition the loss of speed with aging has been implicated in increased errors (Mayr & Kliegl, 1993). However, in looking at the relationships between these two constructs younger adults almost always perform better than older adults. This study will equate performance between younger and older adults on a cued recall task at multiple levels of recall. If older adults are able to compensate for lower levels of processing speed on cued recall tasks with their vocabulary knowledge the differences should be indicated by a larger predictive ability of vocabulary in regression analysis. Previous research indicated that both younger and older adults draw on speed and vocabulary knowledge in a similar way when performing simple verbal tasks (Salthouse, 1993). This project will add to the understanding of these constructs' contributions to memory in a new way, if older adults are forced to perform at a level equal to that of younger adults they may compensate for lower quantities of processing speed by relying on their concrete knowledge abilities.

AUDITORY SELECTIVE ATTENTION AS MEASURED BY A DICHOTIC LISTENING PARADIGM IN YOUNG AND OLDER ADULTS

Kelly J. Shea-Miller, M.A., CCC-A, Communication Sciences and Disorders, University of Georgia

The ability to selectively attend to auditory information decreases with age. Modified dichotic listening paradigms are often used to demonstrate this age effect. A pilot study looking at direct report dichotic listening in younger and older adults found no significant age effects. In fact, all group differences in dichotic performance could be explained by peripheral hearing impairment. The lack of an age effect in such a popular paradigm is surprising and needs to be examined closely due to its disagreement with previous research. The purpose of this study is to expand the investigation of age-related changes in dichotic listening performance to include two types of dichotic paradigms and listeners of advanced age. Specifically, this study compares the performance of four groups of listeners, young (20-30 years), older (65-75 years), older (65-75 years) hearing impaired adults and advanced age hearing impaired adults (80-90 years), on a direct report (DR) and free report (FR) dichotic listening paradigm. Participants will be tested using dichotic nonsense syllables during two sessions. Group performance will be compared using the student's t-test. Through careful control of age, hearing levels, and test paradigm, this study will be able to determine if age-related changes in auditory selective attention exist in a group of healthy elders.

INSULIN AND GLUCOSE RESPONSES TO 1 WEEK OF RESISTANCE EXERCISE IN OLDER MEN: RELATION TO VISCERAL FAT

Kristie A. Skinner, M.A., Exercise Science, University of Georgia

Advancing age, with accompanying increases in physical inactivity and body weight, contribute to the development of insulin resistance, impaired glucose tolerance and non-insulin-dependent diabetes mellitus (NIDDM) (4). Aerobic and resistance exercise improves insulin resistance and impaired glucose tolerance (3; 8;15). Some of these benefits of exercise occur after a single bout of exercise (2; 5;15;17;18), with additional improvements resulting from chronic exercise. The time course of the additional improvements is unknown. Whether there is a cumulative, augmented effect of successive bouts of acute exercise is unknown. The purpose of this study is to examine the effects of three successive bouts of acute resistance exercise performed in one week on blood glucose and insulin responses, and their relation of visceral fat, in older men. Twenty-five sedentary, apparently-healthy, older men will complete three bouts of resistance exercise within 1 week to determine if there is an additive effect on blood glucose and insulin responses, compared to a single bout of exercise. Fasting oral glucose tolerance tests (OGTT), in which glucose, insulin and C-peptide responses to a glucose challenge are measured, will be administered after (1) a 12-hour fast (control), (2) 24-hours after the first and third exercise sessions to assess the responses to a single bout, and three successive bouts, of acute resistance exercise; and, (3) 72-hours after the third exercise session, to assess more-persistent training adaptations. The relation of the insulin and glucose responses to visceral fat measured by magnetic resonance imaging also will be examined. The results of this study will provide new information on the value of resistance exercise for improving insulin resistance and glucose tolerance, and for preventing the development of NIDDM, in older men.

NEGATIVE AGE STEREOTYPES AND MEMORY PERFORMANCE OF OLDER ADULTS

R. Renee Stein, M.S., Department of Psychology, Georgia Institute of Technology

Negative stereotypes about aging and cognitive ability have consistently been found in the literature (Kite & Johnson, 1988) and are held by people of all ages (Heckhausen, Dixon, & Baltes, 1989). A small but growing body of literature has investigated the impact that these negative age stereotypes have on older adults' adaptive functioning in the memory domain. The goal of the proposed research is to further examine this phenomenon. Three studies are proposed to specifically address the research questions of interest and are intended to broaden our understanding of how deeply enculturated negative stereotypes about aging and cognition may influence memory performance in older adults. The first study seeks to explore the nature of the contextual factors (instructions preceding the memory task) that may elicit negative age stereotypes for older adults in a memory task environment. Using knowledge gained from the first study, the second study will more directly measure the extent to which different instructional sets actually evoke negative stereotypes for older adults. Finally, the third study will examine the influence of negative age stereotypes on the memory performance of older adults by providing a conceptual replication and extension of Rahhal and Hasher's (1998) study.
Lastly, to elucidate how negative age stereotypes operate to influence performance, the third study will investigate anxiety as a possible mediating mechanism.