Significant individual differences in the trajectories of cognitive aging and in age-related changes of brain structure and function have been reported in the past half-century. In some individuals, ...significant pathological changes in the brain are observed in conjunction with relatively well-preserved cognitive performance. Multiple constructs have been invoked to explain this paradox of resilience, including brain reserve, cognitive reserve, brain maintenance, and compensation. The aim of this session of the Cognitive Aging Summit III was to examine the overlap and distinctions in definitions and measurement of these constructs, to discuss their neural and behavioral correlates and to propose plausible mechanisms of individual cognitive resilience in the face of typical age-related neural declines.
•People vary in their ability to maintain good cognition despite significant neuropathology.•Reserve, maintenance, and compensation may explain the paradox of resilience.•These constructs may have passive (structural) or active (functional) brain basis.•Identification of reliable reflective indicators will boost validity of reserve construct.•Progress requires integrating animal and human neuroimaging in longitudinal designs.
Cognitive ageing research examines the cognitive abilities that are preserved and/or those that decline with advanced age. There is great individual variability in cognitive ageing trajectories. Some ...older adults show little decline in cognitive ability compared with young adults and are thus termed 'optimally ageing'. By contrast, others exhibit substantial cognitive decline and may develop dementia. Human neuroimaging research has led to a number of important advances in our understanding of the neural mechanisms underlying these two outcomes. However, interpreting the age-related changes and differences in brain structure, activation and functional connectivity that this research reveals is an ongoing challenge. Ambiguous terminology is a major source of difficulty in this venture. Three terms in particular - compensation, maintenance and reserve - have been used in a number of different ways, and researchers continue to disagree about the kinds of evidence or patterns of results that are required to interpret findings related to these concepts. As such inconsistencies can impede progress in both theoretical and empirical research, here, we aim to clarify and propose consensual definitions of these terms.
Cognitive abilities are important predictors of educational and occupational performance, socioeconomic attainment, health, and longevity. Declines in cognitive abilities are linked to impairments in ...older adults’ everyday functions, but people differ from one another in their rates of cognitive decline over the course of adulthood and old age. Hence, identifying factors that protect against compromised late-life cognition is of great societal interest. The number of years of formal education completed by individuals is positively correlated with their cognitive function throughout adulthood and predicts lower risk of dementia late in life. These observations have led to the propositions that prolonging education might (a) affect cognitive ability and (b) attenuate aging-associated declines in cognition. We evaluate these propositions by reviewing the literature on educational attainment and cognitive aging, including recent analyses of data harmonized across multiple longitudinal cohort studies and related meta-analyses. In line with the first proposition, the evidence indicates that educational attainment has positive effects on cognitive function. We also find evidence that cognitive abilities are associated with selection into longer durations of education and that there are common factors (e.g., parental socioeconomic resources) that affect both educational attainment and cognitive development. There is likely reciprocal interplay among these factors, and among cognitive abilities, during development. Education–cognitive ability associations are apparent across the entire adult life span and across the full range of education levels, including (to some degree) tertiary education. However, contrary to the second proposition, we find that associations between education and aging-associated cognitive declines are negligible and that a threshold model of dementia can account for the association between educational attainment and late-life dementia risk. We conclude that educational attainment exerts its influences on late-life cognitive function primarily by contributing to individual differences in cognitive skills that emerge in early adulthood but persist into older age. We also note that the widespread absence of educational influences on rates of cognitive decline puts constraints on theoretical notions of cognitive aging, such as the concepts of cognitive reserve and brain maintenance. Improving the conditions that shape development during the first decades of life carries great potential for improving cognitive ability in early adulthood and for reducing public-health burdens related to cognitive aging and dementia.
Although sensitive detection of pathological cognitive aging requires accurate information about the trajectory of normal cognitive aging, prior research has revealed inconsistent patterns of ...age-cognition relations with cross-sectional and longitudinal comparisons. Age trends in four cognitive domains were compared in over 5,000 adults with cross-sectional data, and in almost 1,600 adults with three-occasion longitudinal data. Quasi-longitudinal comparisons, which are similar to cross-sectional comparisons in that there is no prior test experience and are similar to longitudinal comparisons in that the participants are from the same birth cohorts, were also reported. The age trends in quasi-longitudinal comparisons more closely resembled those in cross-sectional comparisons than those in longitudinal comparisons, which suggests that, at least up until about age 65, age-cognition relations in longitudinal comparisons are distorted by prior test experience. Results from cross-sectional and quasi-longitudinal comparisons, which can be assumed to have minimal test experience effects, imply that normal cognitive aging is characterized by nearly linear declines from early adulthood in speed, and accelerating declines in memory and reasoning. However, vocabulary knowledge increased until the decade of the 60's in all three types of comparisons.
50 Years of Cognitive Aging Theory Anderson, Nicole D; Craik, Fergus I. M
The journals of gerontology. Series B, Psychological sciences and social sciences,
01/2017, Letnik:
72, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Abstract
Objectives:
The objectives of this Introduction to the Journal of Gerontology: Psychological Sciences special issue on “50 Years of Cognitive Aging Theory” are to provide a brief overview of ...cognitive aging research prior to 1965 and to highlight significant developments in cognitive aging theory over the last 50 years.
Method:
Historical and recent theories of cognitive aging were reviewed, with a particular focus on those not directly covered by the articles included in this special issue.
Results:
Prior to 1965, cognitive aging research was predominantly descriptive, identifying what aspects of intellectual functioning are affected in older compared with younger adults. Since the mid-1960s, there has been an increasing interest in how and why specific components of cognitive domains are differentially affected in aging and a growing focus on cognitive aging neuroscience.
Discussion:
Significant advances have taken place in our theoretical understanding of how and why certain components of cognitive functioning are or are not affected by aging. We also know much more now than we did 50 years ago about the underlying neural mechanisms of these changes. The next 50 years undoubtedly will bring new theories, as well as new tools (e.g., neuroimaging advances, neuromodulation, and technology), that will further our understanding of cognitive aging.
•Aged male rats are impaired in PAL task acquisition relative to young.•Response-driven behavior translates from 3-D mazes to 2-D touchscreens.•Age-related impairments may stem from proactive ...accumulating interference.
Discovery research in rodent models of cognitive aging is instrumental for identifying mechanisms of behavioral decline in old age that can be therapeutically targeted. Clinically relevant behavioral paradigms, however, have not been widely employed in aged rats. The current study aimed to bridge this translational gap by testing cognition in a cross-species touchscreen-based platform known as paired-associates learning (PAL) and then utilizing a trial-by-trial behavioral analysis approach. This study found age-related deficits in PAL task acquisition in male rats. Furthermore, trial-by-trial analyses and testing rats on a novel interference version of PAL suggested that age-related impairments were not due to differences in vulnerability to an irrelevant distractor, motivation, or to forgetting. Rather, impairment appeared to arise from vulnerability to accumulating, proactive interference, with aged animals performing worse than younger rats in later trial blocks within a single testing session. The detailed behavioral analysis employed in this study provides new insights into the etiology of age-associated cognitive deficits.
•The review presents the detraining impact on the cognition of older adults.•Exercise detraining can reduce or unaltered cognitive function in older adults.•Executive function seems to be the most ...affected by the detraining period.
Objective: Provide a synthesis of the current literature about the effects of detraining on cognitive functions in older adults.
Methods: The PICOS acronym strategy was performed in PubMed/MEDLINE, Web of Science, Cochrane Library and PsycINFO database. The Preferred Reporting Items for Systematic Review and Meta-Analyses statement had been followed in the present study, in which the search was conducted on October 2023. The study selection consisted in original articles including older adults, detraining after training exercise period, use of tests or scales to measure cognitive function. The Downs and Black checklist had been used to assess the studies quality. Sample characteristics, type of previous training, detraining period, cognitive functions measurements and main results were extracted by 2 investigators.
Results: From 1927 studies, 12 studies were included, being 11 studies identified via systematic research, and 1 study by citation search. Older adults, ranged from 60 to 87 years old, were assessed after detraining. The cognitive functions most evaluated were global cognition and executive functions. One study evaluated both cognitive outcome and cerebral blood flow. Most of the studies demonstrated a decline in the cognitive function after detraining.
Conclusion: Exercise detraining period, ranging from 10 days to 16 weeks, can effect negatively the cognitive function in older adults.
Abstract
Background
The objective of this study was to examine the association between education and incidence of accelerated cognitive decline.
Methods
Secondary analyses of data from the Health and ...Retirement Study (HRS), a nationally representative prospective cohort study of U.S. residents were conducted (N = 28,417). Cox proportional hazards survival models were layered on longitudinal mixed-effects modeling to jointly examine healthy cognitive aging and incidence of accelerated cognitive decline consistent with patterns seen in preclinical Alzheimer’s disease and related dementias (ADRD). Replication analyses were completed on a database including 62,485 additional respondents from HRS sister studies. Life expectancy ratios (LER) and 95% confidence intervals (CIs) were reported.
Results
This study replicated research showing that education was positively associated with cognition at baseline. Model fit improved using the survival method compared to random-slopes models alone. Analyses of HRS data revealed that higher education was associated with delayed onset of accelerated cognitive decline (LER = 1.031 95% CI = 1.013–1.015, p < 1E-06). Replication analyses using data from 14 countries identified similar results.
Conclusions
These results are consistent with cognitive reserve theory, suggesting that education reduces risk of ADRD-pattern cognitive decline. Follow-up work should seek to differentiate specific dementia types involved and consider potential mechanisms.
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