Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-23T09:30:00.640Z Has data issue: false hasContentIssue false
  • English
  • Français

Cohort effects in verbal memory function and practice effects: a population-based study

Published online by Cambridge University Press:  11 October 2016

Hiroko H Dodge ,
Jian Zhu ,
Tiffany F. Hughes ,
Beth E. Snitz ,
Chung-Chou H. Chang ,
Erin P. Jacobsen  and
Mary Ganguli
Hiroko H Dodge
Affiliation:
Department of Neurology, Michigan Alzheimer's Disease Center, University of Michigan, Ann Arbor, Michigan, USA Department of Neurology, Layton Aging and Alzheimer's Disease Center, Oregon Health & Science University, Portland, Oregon, USA
Jian Zhu
Affiliation:
Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, Michigan, USA
Tiffany F. Hughes
Affiliation:
Youngstown State University, One University Plaza, Youngstown, Ohio, USA
Beth E. Snitz
Affiliation:
Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
Chung-Chou H. Chang
Affiliation:
Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA Department of Biostatistics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania, USA
Erin P. Jacobsen
Affiliation:
Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
Mary Ganguli*
Affiliation:
Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania, USA
*
Correspondence should be addressed to: Dr. Mary Ganguli, WPIC, 3811 O'Hara Street, Pittsburgh, PA 15213. Email [email protected].
Get access

Abstract

Background:

In many developed countries, cognitive functioning (as measured by neuropsychological tests) appears to be improving over time in the population at large, in parallel with the declining age-specific incidence of dementia. Here, we investigated cohort effects in the age-associated trajectories of verbal memory function in older adults. We sought to determine whether they varied by decade of birth and, if so, whether the change would be explained by increasing educational attainment.

Methods:

Pooling data from two prospective US population-based studies between 1987 and 2015, we identified four birth cohorts born 1902–1911, 1912–1921, 1922–1931, and 1932–1943. Among these cohorts, we compared age-associated trajectories both of performance and of practice effects on immediate and delayed recall of a 10-item Word List. We used mixed effects models, first including birth cohorts and cohort X age interaction terms, and then controlling for education and education X age interaction.

Results:

We observed significant cohort effects in performance (baseline and age-associated trajectories) in both immediate recall and delayed recall, with function improving between the earliest- and latest-born cohorts. For both tests, we also observed cohort effects on practice effects with the highest levels in the latest-born cohorts. Including education in the models did not attenuate these effects.

Conclusions:

In this longitudinal population study, across four decade-long birth cohorts, there were significant improvements in test performance and practice effects in verbal memory tests, not explained by education. Whether this reflects declining disease incidence or other secular trends awaits further investigation.

Keywords

cognitive testingneuropsychological testing
Type
Research Article
Information
International Psychogeriatrics , Volume 29 , Issue 1 , January 2017 , pp. 137 - 148
Copyright
Copyright © International Psychogeriatric Association 2016 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Albano, A. (2013). Equate: Statistical methods for test score equating. R package Version 1.2-0. Available at: http://CRAN.R-project.org/package=equate.Google Scholar
Becker, J. T., Boller, F., Saxton, J. and McGonigle-Gibson, K. L. (1987). Normal rates of forgetting of verbal and non-verbal material in Alzheimer's disease. Cortex, 23, 59–72.Google Scholar
Bordone, V., Scherbov, S. and Steiber, N. (2015). Smarter every day: the deceleration of population ageing in terms of cognition. Intelligence, 52, 90–96.Google Scholar
Centers for Disease Control and Prevention. (2016). Trends in Current Cigarette Smoking Among High School Students and Adults, United States, 1965-2014. National Health Interview Survey, 1965-2014. Available at: http://www.cdc.gov/tobacco/data_statistics/tables/trends/cig_smoking/index.htm; last accessed 2016.Google Scholar
Christensen, K. et al. (2013). Physical and cognitive functioning of people older than 90 years: a comparison of two Danish cohorts born 10 years apart. Lancet, 382, 1507–13.Google Scholar
Dodge, H. H., Wang, C. N., Chang, C. C. and Ganguli, M. (2011). Terminal decline and practice effects in older adults without dementia: the MoVIES project. Neurology, 77, 722–30.Google Scholar
Dodge, H. H., Zhu, J., Lee, C. W., Chang, C. C. and Ganguli, M. (2014). Cohort effects in age-associated cognitive trajectories. Journals of Gerontology Series A: Biological Sciences and Medical Sciences, 69, 687–94.Google Scholar
Efron, B. (1979). Bootstrap methods: another look at the jackknife. Annals of Statistics, 7, 1–26.Google Scholar
Flegal, K. M., Carroll, M. D., Kit, B. K. and Ogden, C. L. (2012). Prevalence of obesity and trends in the distribution of body mass index among US adults, 1999-2010. JAMA, 307, 491–7.Google Scholar
Flynn, J. R. (1987). Massive IQ gains in 14 nations - what Iq tests really measure. Psychological Bulletin, 101, 171–191.Google Scholar
Freedman, V. A., Aykan, H. and Martin, L. G. (2002). Another look at aggregate changes in severe cognitive impairment: further investigation into the cumulative effects of three survey design issues. The Journals of Gerontology Series B: Psychological Sciences and Social Sciences, 57, S126–31.Google Scholar
Fuld, P. A. (1981). Fuld Object-Memory Evaluation. Woodale, IL: Stoelting Co.Google Scholar
Ganguli, M., Dodge, H. H., Chen, P., Belle, S. and DeKosky, S. T. (2000). Ten-year incidence of dementia in a rural elderly US community population: the MoVIES Project. Neurology, 54, 1109–16.Google Scholar
Ganguli, M., Snitz, B. E., Lee, C. W., Vanderbilt, J., Saxton, J. A. and Chang, C. C. (2010). Age and education effects and norms on a cognitive test battery from a population-based cohort: the monongahela-youghiogheny healthy aging team. Aging and Mental Health, 14, 100–7.Google Scholar
Gregg, E. W. et al. (2014). Changes in diabetes-related complications in the United States, 1990-2010. New England Journal of Medicine, 370, 1514–23.Google Scholar
Gross, A. L. et al. (2015). Predictors of retest effects in a longitudinal study of cognitive aging in a diverse community-based sample. Journal of the International Neuropsychological Society, 21, 506–18.Google Scholar
Koton, S. et al. (2014). Stroke incidence and mortality trends in US communities, 1987 to 2011. JAMA, 312, 259–68.Google Scholar
Laird, N. M. (1988). Missing data in longitudinal studies. Statistics in Medicine, 7, 305–15.Google Scholar
Langa, K. M. et al. (2008). Trends in the prevalence and mortality of cognitive impairment in the United States: is there evidence of a compression of cognitive morbidity?. Alzheimer's & Dementia, 4, 134–44.Google Scholar
Little, R. J. A. (1995). Modeling the drop-out mechanism in repeated-measures studies. Journal of the American Statistical Association, 90, 1112–21Google Scholar
Livingston, S. A. (2004). Equating Test Scores (without IRT). Princeton, NJ: ETS.Google Scholar
Llewellyn, D. J. and Matthews, F. E. (2009). Increasing levels of semantic verbal fluency in elderly English adults. Neuropsychology, Development, and Cognition. Section B, Aging, Neuropsychology and Cognition, 16, 433–45.Google Scholar
Matthews, F. E. et al. (2013). A two-decade comparison of prevalence of dementia in individuals aged 65 years and older from three geographical areas of England: results of the cognitive function and ageing study I and II. Lancet, 382, 1405–12.CrossRefGoogle ScholarPubMed
Monsell, S. E. et al. (2016). Results from the NACC uniform data set neuropsychological battery crosswalk study. Alzheimer Disease and Associated Disorders, 30, 134–39.Google Scholar
Morris, J. C. et al. (1989). The Consortium to Establish a Registry for Alzheimer's Disease (CERAD). Part I. Clinical and neuropsychological assessment of Alzheimer's disease. Neurology, 39, 1159–65.Google Scholar
O'Brien, E., Wu, K. B. and Baer, D. (2010). Older Americans in Poverty: A Snapshot. Washington, DC: AARP Public Policy Institute.Google Scholar
Osone, A., Arai, R., Hakamada, R. and Shimoda, K. (2016). Cognitive and brain reserve in conversion and reversion in patients with mild cognitive impairment over 12 months of follow-up. Journal of Clinical and Experimental Neuropsychology Epublished ahead of print. doi: 10.1080/13803395.2016.1191620.Google Scholar
Qiu, C., von Strauss, E., Backman, L., Winblad, B. and Fratiglioni, L. (2013). Twenty-year changes in dementia occurrence suggest decreasing incidence in central Stockholm, Sweden. Neurology, 80, 1888–94.CrossRefGoogle ScholarPubMed
Sacuiu, S. et al. (2010). Secular changes in cognitive predictors of dementia and mortality in 70-year-olds. Neurology, 75, 779–85.Google Scholar
Satizabal, C. L., Beiser, A. S., Chouraki, V., Chene, G., Dufouil, C. and Seshadri, S. (2016). Incidence of dementia over three decades in the Framingham heart study. New England Journal of Medicine, 374, 523–32.Google Scholar
Schrijvers, E. M., Verhaaren, B. F., Koudstaal, P. J., Hofman, A., Ikram, M. A. and Breteler, M. M. (2012). Is dementia incidence declining?: Trends in dementia incidence since 1990 in the Rotterdam study. Neurology, 78, 1456–63.Google Scholar
Stern, Y. (2002). What is cognitive reserve? Theory and research applications of the reserve concept. Journal of the International Neuropsychological Association, 8, 448–460.CrossRefGoogle ScholarPubMed
Wechsler, D. (1987). Wechsler Memory Scale Revised. San Antonio, TX: The Psychological Corporation.Google Scholar
Supplementary material: File

Dodge supplementary material

Supplementary Table

Download Dodge supplementary material(File)
File 26.6 KB