No protective effects of education during normal cognitive aging: Results from the 6-year follow-up of the Maastricht Aging Study.

Recent large-scale longitudinal aging studies question earlier claims that higher education protects against cognitive decline in older age. In the present study, the authors addressed this issue by determining whether educational level had an attenuating effect on the rate of cognitive change assessed with a broad range of neuropsychological tests in a community sample of 872 healthy individuals aged 49 to 81 years at baseline. The participants were followed for 6 years and were tested 3 times (at baseline and at 3 and 6 years after baseline). Results of linear mixed-model analyses showed that education had no significant effect on cognitive change over time. These results are discussed in terms of the age range of the sample, definition and range of education, cognitive measures used, length of the study and number of consecutive assessments, and confounding effect of health. The findings question the extent of the presumed protective effects of higher education on cognitive decline during normal aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The cognitive reserve hypothesis: A longitudinal examination of age-associated declines in reasoning and processing speed.

The term cognitive reserve is frequently used to refer to the ubiquitous finding that, during later life, those higher in experiential resources (e.g., education, knowledge) exhibit higher levels of cognitive function. This observation may be the result of either experiential resources playing protective roles with respect to the cognitive declines associated with aging or the persistence of differences in functioning that have existed since earlier adulthood. These possibilities were examined by applying accelerated longitudinal structural equation (growth curve) models to 5-year reasoning and speed data from the no-contact control group (N = 690; age 65–89 years at baseline) of the Advanced Cognitive Training for Independent and Vital Elderly study. Vocabulary knowledge and years of education, as markers of cognitive reserve, were related to levels of cognitive functioning but unrelated to rates of cognitive change, both before and after the (negative) relations between levels and rates were controlled for. These results suggest that cognitive reserve reflects the persistence of earlier differences in cognitive functioning rather than differential rates of age-associated cognitive declines. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

News of cognitive cure for age-related brain shrinkage is premature: A comment on Burgmans et al. (2009).

The extant longitudinal literature consistently supports the notion of age-related declines in human brain volume. In a report on a longitudinal cognitive follow-up with cross-sectional brain measurements, Burgmans and colleagues (2009) claim that the extant studies overestimate brain volume declines, presumably due to inclusion of participants with preclinical cognitive pathology. Moreover, the authors of the article assert that such declines are absent among optimally healthy adults who maintain cognitive stability for several years. In this comment accompanied by reanalysis of previously published data, we argue that these claims are incorrect on logical, methodological, and empirical grounds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender and the Natural History of Self-Rated Health: A 59-Year Longitudinal Study.

Self-ratings of health are uniquely predictive of morbidity and mortality, and they encompass people's evaluations of many medical, psychological, and social conditions in their lives. However, the longitudinal trajectory of self-rated health has not been evaluated to date. In the present study, 59-year longitudinal multilevel analyses (1940-1999) of data from 1,411 men and women revealed that self-rated health was relatively stable until age 50 and then began to decrease in an accelerating fashion through the rest of the life course. Men had higher self-rated health throughout most of adulthood than did women but had steeper linear rates of decline. As a result, the gender difference in self-rated health disappeared by late adulthood. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Latent variable analyses of age trends of cognition in the Health and Retirement Study, 1992-2004.

The present study was conducted to better describe age trends in cognition among older adults in the longitudinal Health and Retirement Study (HRS) from 1992 to 2004 (N = 17,000). The authors used contemporary latent variable models to organize this information in terms of both cross-sectional and longitudinal inferences about age and cognition. Common factor analysis results yielded evidence for at least 2 common factors, labeled Episodic Memory and Mental Status, largely separable from vocabulary. Latent path models with these common factors were based on demographic characteristics. Multilevel models of factorial invariance over age indicated that at least 2 common factors were needed. Latent curve models of episodic memory were based on age at testing and showed substantial age differences and age changes, including impacts due to retesting as well as several time-invariant and time-varying predictors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A medication screening tool for cognitive aging researchers.

A Web-based medication screening toll that provides researchers with information about side effects associated with medications commonly used by older participants is described. this tool can be used for research purposes to better separate the effects of normal, healthy aging processes from the deleterious effects often associated with medication usage. Researchers can use this tool, called SMART (Screening Medications: Aging Research Taxonomy), to (a) obtain information pertaining to the cognitive, sensory, and motor side effects associated with specific medications, and (b) screen medications in their research for side effect severity. The Web address for the tool is www.psychology.gatech.edu/SMART. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The "common cause hypothesis" of cognitive aging: Evidence for not only a common factor but also specific associations of age with vision and grip strength in a cross-sectional analysis.

A prominent hypothesis in cognitive aging is the existence of a common factor that is responsible for age-related deterioration in cognitive and noncognitive processes. A multiple indicators, multiple causes model was used to examine the nature of this common factor and its relationship to age, gender, and the apolipoprotien E (APOE) genotype. The common factor was modeled by using 10 indicator variables with 374 participants aged between 77.4 and 98.7 years. A latent factor was identified, with all indicators except blood pressure loading significantly. This factor could be established in 2 age strata within the sample. After controlling for the effects of gender, APOE, and level of education, direct effects of age were seen on visual functioning and grip strength. APOE was significantly associated with memory but not with the common factor. The findings suggest that a number of specific processes may operate concurrently with the common cause factor. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Subjective cognitive complaints and longitudinal changes in memory and brain function.

Objective: Subjective cognitive complaints are often used in the diagnosis of memory and other cognitive impairment. This study examined whether cognitive complaints are associated with longitudinal changes in cognition and cross-sectional differences in regional brain function during memory performance in 98 participants with a mean age of 75. Method: The Cognitive Failures Questionnaire (CFQ) assessed cognitive complaints and mixed effects regression models were used to determine whether mean CFQ scores predicted rates of change in cognitive function over a period of 11.5 years. Results: Higher CFQ scores, reflecting increased subjective complaints, were associated with steeper rates of decline in immediate and delayed recall on the California Verbal Learning Test. Voxel-based regression analysis was used to determine the cross-sectional relationship between CFQ scores and regional cerebral blood flow measured by PET during a resting condition and during verbal and figural memory tasks. Higher levels of cognitive complaints were associated with increased activity in insular, lingual and cerebellar areas during memory tasks. Conclusions: These findings offer some support for the validity of subjective cognitive complaints as markers of age related changes in memory and brain activity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impact of age on long-term cognitive function after traumatic brain injury.

Objective: To examine the association of age and time postinjury with cognitive outcome 5–22 years following traumatic brain injury (TBI), in relation to matched uninjured controls. Methods: One hundred twelve participants with mild to very severe TBI, aged 16–81 years at the time of injury, were cognitively assessed on measures of processing speed and attention, verbal and visual memory, executive function, and working memory. Results were compared with those of 112 healthy controls individually matched for current age, gender, education, and estimated IQ. Results: Older injured individuals performed worse than did younger injured individuals across all cognitive domains, after controlling for the performance of controls. In relation to matched controls, long-time survivors performed disproportionately worse than did more recently injured individuals, irrespective of age. Conclusions: After maximum spontaneous recovery from TBI, poorer cognitive functioning appears to be associated with both older age at the time of injury and increased time postinjury. These findings have implications for prognosis, early treatment recommendations, and long-term issues of differential diagnosis and management planning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Theory of mind associations with other cognitive functions and brain imaging in normal aging.

The study investigated age-related differences in theory of mind and explored the relationship between this ability, other cognitive abilities, and structural brain measures. A cohort of 106 adults (ages 50–90 years) was recruited. Participants completed tests of theory of mind, verbal and performance intelligence, executive function, and information processing speed and underwent structural magnetic resonance imaging (measurement of whole brain volume, volume of white matter hyperintensities, and diffusion tensor imaging of white matter integrity). Theory of mind ability declined with increasing age, and the relationship between theory of mind and age was fully mediated by performance intelligence, executive function, and information processing speed and was partially mediated by verbal intelligence. Theory of mind performance correlated significantly with diffusion tensor imaging measures of white matter integrity but not with volume of white matter hyperintensities or whole-brain volume. Theory of mind age-related decline may not be independent of other cognitive functions; it may also be particularly susceptible to changes in white matter integrity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age changes in processing speed as a leading indicator of cognitive aging.

Bivariate dual change score models were applied to longitudinal data from the Swedish Adoption/Twin Study of Aging to compare the dynamic predictions of 2-component theories of intelligence and the processing speed theory of cognitive aging. Data from up to 5 measurement occasions covering a 16-year period were available from 806 participants ranging in age from 50 to 88 years at the first measurement wave. Factors were generated to tap 4 general cognitive domains: verbal ability, spatial ability, memory, and processing speed. Model fitting indicated no dynamic relationship between verbal and spatial factors, providing no support for the hypothesis that age changes in fluid abilities drive age changes in crystallized abilities. The results suggest that, as predicted by the processing speed theory of cognitive aging, processing speed is a leading indicator of age changes in memory and spatial ability, but not verbal ability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The influence of aging and frontal function on the neural correlates of regulative and evaluative aspects of cognitive control.

The influence of aging and frontal function on the neural correlates of regulative and evaluative control was examined by means of event-related brain potentials (ERPs). The behavioral data indicated that interference was greater for older than for younger adults and that this difference was mediated by frontal function. The ERP data revealed effects of aging on the neural correlates of both regulative and evaluative control. Prestimulus neural activity was correlated with response time and frontal function, and these relationships were moderated by the response-to-stimulus interval (RSI); the poststimulus data also revealed age-related differences in the neural correlates of evaluative control that interacted with RSI. These data support predictions derived from the context processing deficit theory of aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive engagement and cognitive aging: Is openness protective?

The purpose of this study was to examine whether openness to experience is related to longitudinal change in cognitive performance across advancing age. Participants were 857 individuals from the Swedish Adoption/Twin Study of Aging (SATSA). Factors for 5 cognitive domains were created, including verbal ability, spatial ability, memory, processing speed, and a global score, g. Latent growth curve models were used to assess level and longitudinal trajectories of cognitive performance. It was hypothesized that individuals who endorsed higher levels of openness would have higher cognitive test scores and lesser rates of cognitive decline. As predicted, higher openness to experience was associated with significantly higher performance across all cognitive tests for both men and women even after adjusting for education, cardiovascular disease, and activities of daily living. Openness, however, was not predictive of differences in the trajectories of cognitive performance over age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Introduction to the special section on cognitive plasticity in the aging mind.

Decades of cognitive aging research have led to a picture of the aging mind that is primarily characterized by gradual, though relatively broad, cognitive decline across the life span. Until recently, relatively little attention has been devoted to the question of whether there are ways to slow down, if not stop, this decline. With the special section on cognitive plasticity in the aging mind, we respond to what seems to be a beginning of the reversal of this trend (e.g., Kramer & Willis, 2002). In this short introduction, the author provides some context and a preview of the articles that appear in the special section. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual function and cognitive aging: Differential role of contrast sensitivity in verbal versus spatial tasks.

Cognitive and sensory function are correlated in older adults. Sensory function may provide an index of neurological integrity (common-cause hypothesis). Declining sensory input may also directly impair cognition (direct-cause hypothesis). Accordingly, sensory function should more strongly predict cognitive performance and should account for more age-related variability in tasks with higher sensory demands. In a cross-sectional adult life span sample, visual contrast sensitivity was a better predictor and accounted for more of the age-related variability in high sensory-demand tasks, compared with low sensory-demand tasks, consistent with the direct-cause hypothesis. The results suggest a direct role for sensory function in cognitive aging when task conditions place heavy demands on sensory processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Knox conference on the relation of psychology to general education.

A summary report of a conference sponsored by the Committee on the Relation of Psychology to General Education. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cohort differences in cognitive aging and terminal decline in the Seattle Longitudinal Study.

Life span researchers have long been interested in how and why fundamental aspects of human ontogeny differ between cohorts of people who have lived through different historical epochs. When examined at the same age, later born cohorts are often cognitively and physically fitter than earlier born cohorts. Less is known, however, about cohort differences in the rate of cognitive aging and if, at the very end of life, pervasive mortality-related processes overshadow and minimize cohort differences. We used data on 5 primary mental abilities from the Seattle Longitudinal Study (Schaie, 2005) to compare both age-related and mortality-related changes between earlier born cohorts (1886–1913) and later born cohorts (1914–1948). Our models covary for several individual and cohort differences in central indicators of life expectancy, education, health, and gender. Age-related growth models corroborate and extend earlier findings by documenting level differences at age 70 of up to 0.50 SD and less steep rates of cognitive aging on all abilities between 50 and 80 years of age favoring the later born cohort. In contrast, mortality-related models provide limited support for positive cohort differences. The later born cohort showed steeper mortality-related declines. We discuss possible reasons why often reported positive secular trends in age-related processes may not generalize to the vulnerable segment of the population that is close to death and suggest routes for further inquiry. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Multilingualism and cognitive state in the oldest old.

In this study, the authors examined whether the number of languages a person speaks predicts performance on 2 cognitive-screening tests. Data were drawn from a representative sample of the oldest Israeli Jewish population (N = 814, M age = 83.0 years; SD = 5.4) that was interviewed first in 1989 and then twice more within the following 12 years. Cognitive state differed significantly among groups of self-reported bilingual, trilingual, and multilingual individuals at each of the 3 interview waves. Regression analyses showed that the number of languages spoken contributed to the prediction of cognitive test scores beyond the effect of other demographic variables, such as age, gender, place of birth, age at immigration, or education. Multilingualism was also found to be a significant predictor of cognitive state in a group of individuals who acquired no formal education at all. Those who reported being most fluent in a language other than their mother tongue scored higher on average than did those whose mother tongue was their best language, but the effect of number of languages on cognitive state was significant in both groups, with no significant interaction. Results are discussed in the context of theories of cognitive reserve. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Different storage and retrieval deficits in normal aging and mild cognitive impairment: A multinomial modeling analysis.

The authors compared patients with mild cognitive impairment with healthy older adults and young control participants in a free recall test in order to locate potential qualitative differences in normal and pathological memory decline. Analysis with an extended multitrial version of W. H. Batchelder and D. M. Riefer's (1980) pair-clustering model revealed globally decelerated learning and an additional retrieval deficit in patients with mild cognitive impairment but not in healthy older adults. Results thus suggest differences in memory decline between normal and pathological aging that may be useful for the detection of risk groups for dementia, and they illustrate the value of model-based disentangling of processes and of multitrial tests for early detection of dementia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recollection- and familiarity-based memory in healthy aging and amnestic mild cognitive impairment.

Little is known about the cognitive mechanisms of the memory impairment associated with amnestic mild cognitive impairment (aMCI). We explored recollection and familiarity in 27 healthy young adults, 45 healthy older adults, and 17 individuals with aMCI. Relative to the younger adults, recollection was reduced in the older adults, especially among those with aMCI. Familiarity did not differ among groups. In the healthy younger and older adults, better performance on a set of clinical memory measures that are sensitive to medial temporal lobe functioning was associated with greater recollection. In addition, among the healthy older adults better executive functioning was also associated with greater recollection. These results are consistent with the notion that recollection is a product of strategic processes mediated by the prefrontal cortex that suppport the retrieval of context-dependent memories from the hippocampus. Hippocampal atrophy associated with aMCI may disrupt this brain network, and thereby interfere with recollection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)