Structural equation models of relationships between exercise and cognitive abilities.

Data were obtained from 300 men and women aged 55 to 91. Separate structural equation models of relationships between physical exercise and 3 cognitive performance variables—reaction time (RT), working memory, and reasoning—fit the data well. Other variables in the models were age, health, education, and morale. Age and exercise affected each performance variable directly; education had a direct effect on reasoning only. There were also indirect effects of age and health on performance variables, mediated through exercise. The main hypothesis of the study, that exercise contributes to performance, was supported. A large decrease in model fit resulted when the path from exercise to each variable was deleted. Hypotheses that age-related deficits are primarily accounted for by lack of exercise or by poor health were not supported. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Correction to Emery, Hale, and Myerson (2008).

Reports an error in "Age differences in proactive interference, working memory, and abstract reasoning" by Lisa Emery, Sandra Hale and Joel Myerson (Psychology and Aging, 2008[Sep], Vol 23[3], 634-645). The original article contained an incorrect DOI. The correct DOI is as follows: 10.1037/a0012577. (The following abstract of the original article appeared in record 2008-13050-014.) It has been hypothesized that older adults are especially susceptible to proactive interference (PI) and that this may contribute to age differences in working memory performance. In young adults, individual differences in PI affect both working memory and reasoning ability, but the relations between PI, working memory, and reasoning in older adults have not been examined. In the current study, young, old, and very old adults performed a modified operation span task that induced several cycles of PI buildup and release as well as two tests of abstract reasoning ability. Age differences in working memory scores increased as PI built up, consistent with the hypothesis that older adults are more susceptible to PI, but both young and older adults showed complete release from PI. Young adults' reasoning ability was best predicted by working memory performance under high PI conditions, replicating M. Bunting (2006). In contrast, older adults' reasoning ability was best predicted by their working memory performance under low PI conditions, thereby raising questions regarding the general role of susceptibility to PI in differences in higher cognitive function among older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in proactive interference, working memory, and abstract reasoning.

[Correction Notice: An erratum for this article was reported in Vol 23(4) of Psychology and Aging (see record 2008-19072-007). The original article contained an incorrect DOI. The correct DOI is as follows: 10.1037/a0012577.] It has been hypothesized that older adults are especially susceptible to proactive interference (PI) and that this may contribute to age differences in working memory performance. In young adults, individual differences in PI affect both working memory and reasoning ability, but the relations between PI, working memory, and reasoning in older adults have not been examined. In the current study, young, old, and very old adults performed a modified operation span task that induced several cycles of PI buildup and release as well as two tests of abstract reasoning ability. Age differences in working memory scores increased as PI built up, consistent with the hypothesis that older adults are more susceptible to PI, but both young and older adults showed complete release from PI. Young adults' reasoning ability was best predicted by working memory performance under high PI conditions, replicating M. Bunting (2006). In contrast, older adults' reasoning ability was best predicted by their working memory performance under low PI conditions, thereby raising questions regarding the general role of susceptibility to PI in differences in higher cognitive function among older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strength in the lower limbs, visual contrast sensitivity, and simple reaction time predict cognition in older women.

The authors investigated the association between sensorimotor variables indicative of biological aging and cognition. A community sample of 202 women ages 60–86 was assessed on 5 measures of lower limb strength, visual contrast sensitivity (VCS), and reaction time (RT). Hierarchical multiple regression revealed that the sensorimotor variables explained age-related variance in measures of reasoning and total variance in measures of reasoning after education, health, mood, and physical activity were controlled for. It is concluded that in addition to better known predictors of cognitive aging, such as RT and VCS, lower limb strength is an important predictor of performance on cognitive tests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Can training in a real-time strategy video game attenuate cognitive decline in older adults?

Declines in various cognitive abilities, particularly executive control functions, are observed in older adults. An important goal of cognitive training is to slow or reverse these age-related declines. However, opinion is divided in the literature regarding whether cognitive training can engender transfer to a variety of cognitive skills in older adults. In the current study, the authors trained older adults in a real-time strategy video game for 23.5 hr in an effort to improve their executive functions. A battery of cognitive tasks, including tasks of executive control and visuospatial skills, were assessed before, during, and after video-game training. The trainees improved significantly in the measures of game performance. They also improved significantly more than the control participants in executive control functions, such as task switching, working memory, visual short-term memory, and reasoning. Individual differences in changes in game performance were correlated with improvements in task switching. The study has implications for the enhancement of executive control processes of older adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Improving aerobic capacity in healthy older adults does not necessarily lead to improved cognitive performance.

The effects of aerobic exercise training in a sample of 85 older adults were investigated. Ss were assigned randomly to either an aerobic exercise group, a nonaerobic exercise (yoga) group, or a waiting-list control group. Following 16 weeks of the group-specific protocol, all of the older Ss received 16 weeks of aerobic exercise training. The older adults demonstrated a significant increase in aerobic capacity (cardiorespiratory fitness). Performance on reaction-time tests of attention and memory retrieval was slower for the older adults than for a comparison group of 24 young adults, and there was no improvement in the older adults' performance on these tests as a function of aerobic exercise training. Results suggest that exercise-related changes in older adults' cognitive performance are due either to extended periods of training or to cohort differences between physically active and sedentary individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-efficacy beliefs and change in cognitive performance: MacArthur studies on Successful Aging.

Data from a cohort of relatively high functioning, older men and women were used to test the hypothesis that stronger self-efficacy beliefs predict better maintenance of cognitive performance. Structural equation modeling revealed that stronger baseline instrumental efficacy beliefs predicted better verbal memory performance at follow-up among men but not among women, controlling for baseline verbal memory score and sociodemographic and health status characteristics. For both men and women there were no significant associations between either type of self-efficacy beliefs and measures of nonverbal memory, abstraction, or spatial ability. Consistent with previous research showing relationships between baseline cognitive performance and change in self-efficacy beliefs, better abstraction ability was also predictive of increases in instrumental efficacy beliefs among the men. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive ability at age 11 and 70 years, information processing speed, and APOE variation: The Lothian Birth Cohort 1936 study.

The e4 allele of the apolipoprotein E (APOE) gene confers risk of Alzheimer's disease and, in some studies, relates to cognitive ability and decline in older people without Alzheimer's disease. Its relationship with processing speed, a contributor to cognitive decline with age, is largely unknown. This study tests the association of APOE with cognition and speed, with and without covarying childhood mental ability. The 1,013 participants were tested on cognitive ability at age 11 as part of the Scottish Mental Survey of 1947 and, at age 70, were tested on reasoning, working memory, information processing speed, and executive function. The results showed that APOE was associated with the general cognitive factor, 2 nonverbal tests, and choice reaction time (RT) variability; as expected, the e4 allele was the risk allele. RT measures and a general speed factor were nonlinearly related to APOE when factoring childhood ability (p     

Individual differences in cross-sectional and 3-year longitudinal memory performance across the adult life span.

Reports individual differences analyses of performance on list and prose memory tasks for 250 men and 258 women (aged 55–84 yrs). Being retested, higher reasoning and vocabulary scores, and female gender predicted better prose recall and list recognition performance. For list recall, retest status, age, years of schooling, and gender, as well as reasoning and vocabulary, were reliable independent predictors. After 3 yrs, 106 men and 121 women returned for a retest. Analysis of individual differences in 3-yr performance indicated that, once Time 1 performance had been partialed, individual change could be predicted by age or reasoning, but neither variable uniquely accounted for change. Analysis of data of individuals who experienced considerable decline or improvement in 3-yr scores indicated that decline was consistently associated with advanced age. Ramifications for theoretical models in memory research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of adult age and working memory on reasoning and spatial abilities.

Three predictions were derived from the hypothesis that adult age differences in certain measures of cognitive functioning are attributable to age-related reductions in a processing resource such as working-memory capacity. Each prediction received at least some degree of empirical support in a study involving 120 males ranging between 20 and 79 years of age. First, older adults exhibited greater impairments of performance than did young adults when task complexity increased and more demands were placed on the limited processing resources: second, the magnitudes of these complexity effects were highly correlated across verbal (reasoning) and spatial (paper folding) tasks. Finally, statistical control of an index of a working-memory processing resource attenuated the effects of age on the measures of cognitive performance. It was concluded that further progress in understanding the mechanisms of the relation between age and cognitive functioning will require improved conceptualizations of the nature of working memory or other hypothesized mediating constructs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive functioning of older people in relation to social and personality variables.

Examined age differences in performance on memory measures and in subjective ratings of memory adequacy in the context of 12 social, personality, adjustment, and lifestyle measures. Ss were 285 men and women (aged 65–93 yrs) of middle- and working-class backgrounds. Cognitive measures included digit span, word recall, and memory and elaborative processing of a prose passage. Multivariate and univariate analyses revealed that a large proportion of the age differences and virtually all of the social-class differences on memory measures could be accounted for by contextual variables. Education; Intellectual activity; and Extroversion, Neuroticism, and Lie scores on the Eysenck Personality Inventory all accounted for more of the variance in memory performance than did age. Self-rated memory adequacy was not correlated with performance, and although the expected finding of lower ratings by older Ss was obtained with the working-class group, the opposite was true for the middle-class group. (46 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intraindividual Variability May Not Always Indicate Vulnerability in Elders' Cognitive Performance.

This study examined consistency of performance, or intraindividual variability, in older adults' performance on 3 measures of cognitive functioning: inductive reasoning, memory, and perceptual speed. Theoretical speculation has suggested that such intraindividual variability may signal underlying vulnerability or neurologic compromise. Thirty-six participants aged 60 and older completed self-administered cognitive assessments twice a day for 60 consecutive days. Intraindividual variability was not strongly correlated among the 3 cognitive measures, but, over the course of the study, intraindividual variability was strongly intercorrelated within a task. Higher average performance on a measure was associated with greater performance variability, and follow-up analyses revealed that a higher level of intraindividual variability is positively associated with the magnitude of a person's practice-related gain on a particular measure. The authors argue that both adaptive (practice-related) and maladaptive (inconsistency-related) intraindividual variability may exist within the same individuals over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The moderating influence of physical fitness on age gradients in vigilance and serial choice responding tasks.

The moderating influence of physical fitness on age gradients in measures obtained from vigilance and serial choice responding tasks is examined in a sample of 90 postal workers. Physiological data relating to aerobic fitness determined fitness level within 2 age groups: younger participants ages 18 to 30 years (M ?=?25.19; 24 men, 24 women) and older participants ages 43 to 62 years (M ?=?49.19; 20 men, 22 women). A performance decrement across time was found in several measures, and some variation as a function of age was apparent. However, post hoc statistical analyses did not indicate this was due to older adults underperforming younger adults. According to predictions, significant Age?×?Fitness interactions showed older less fit workers to consistently underperform other participants. The findings suggest that older less fit individuals have lower signal sensitivity and processing speed than older fitter people and younger individuals. Results are discussed in relation to underlying physiological mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exercise and cardiovascular disease: a new perspective

The oxidation of low density lipoprotein (LDL) has been suggested as a key event in atherogenesis. Paradoxically, exercise, which imposes an oxidative stress, is an important deterrent of cardiovascular disease. In study 1 the oxidizability of LDL was enhanced in exercisers compared with sedentary controls. The lag time of isolated LDL subjected to copper-induced in vitro oxidation was significantly shortened in the exercisers compared with sedentary subjects. This increased sensitivity was not due to a decreased presence of vitamin E. Instead, these findings suggested that the LDL of exercisers may contain increased amounts of preformed lipid peroxides, which account for the increased oxidizability. In study 2, a group x sex ANOVA revealed that male exercisers had a significantly longer mean lag time than male sedentary subjects and that females had similar mean lag times regardless of exercise group. This remained the case when statistical adjustment was made for age, body mass index, blood lipid levels, LDL, and plasma alpha-tocopherol levels. Study 1 exercisers had been in training for a shorter time (< 1 year) than study 2 exercisers (> 2 years). These findings suggest that truly "chronic" exercise (aerobic intensity over several months) decreases the susceptibility of a male exerciser's LDL to undergo oxidation. Conversely, regular aerobic stress during an overall shorter time span creates a more oxidative environment in the body, thus increasing the susceptibility of LDL to undergo oxidation. The oxidative stress of aerobic exercise does not appear to adversely affect the oxidizability of LDL in women.     

Age, exercise, and coding performance.

We investigated the effects of exercise on the coding performance of young and older subjects. Hypotheses were tested that exercise either facilitates spatial localization or reduces susceptibility to distraction in older subjects. In a balanced design, we administered Digit Symbol and Symbol Digit coding tasks to exercisers and nonexercisers at two age levels under conditions of low or high within-task interference. The findings showed higher performance by the exercisers than by the nonexercisers only at the older age level and only with the Symbol Digit task. These findings support the hypothesis that exercise compensates for a loss of spatial localization skills with age. We found no evidence that susceptibility to distraction either increased with age or was affected by chronic exercise. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Older adults with chronic disease: Benefits of group-mediated counseling in the promotion of physically active lifestyles.

In this 12-month trial standard exercise training was compared with a group-mediated cognitive behavioral (GMCB) intervention with respect to effects on long-term adherence and change in physical function of older adults who were either at risk for or had cardiovascular disease. Participants (147 older men and women) were randomized to the 2 treatments. Outcomes included self-reported physical activity, fitness, and self-efficacy. The GMCB treatment produced greater improvements on all outcomes than did standard exercise therapy. Regardless of treatment assignment, men had more favorable change on the study outcomes than did women. Analysis of a self-regulatory process measure in the GMCB group revealed that change in barriers efficacy was related to change in physical activity and fitness. Results suggest that teaching older adults to integrate physical activity into their lives via GMCB leads to better long-term outcomes than standardized exercise therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Placement of endosteal implants combined with chin bone onlay graft for dental reconstruction in patients with grafted alveolar clefts

CONTEXT: Physical activity and fitness are believed to reduce premature mortality, but whether genetic factors modify this effect is not known. OBJECTIVE: To investigate leisure physical activity and mortality with respect to familial aggregation of health habits during childhood and factors that may enable some individuals to achieve higher levels of fitness. DESIGN: Prospective twin cohort study. SETTING: Finland. SUBJECTS: In 1975, at baseline, 7925 healthy men and 7977 healthy women of the Finnish Twin Cohort aged 25 to 64 years who responded to a questionnaire on physical activity habits and known predictors of mortality. Those who reported exercising at least 6 times per month with an intensity corresponding to at least vigorous walking for a mean duration of 30 minutes were classified as conditioning exercisers, those who reported no leisure physical activity were classified as sedentary, and other subjects were classified as occasional exercisers. MAIN OUTCOME MEASURES: All-cause mortality and discordant deaths among same-sex twin pairs from 1977 through 1994. RESULTS: Among the entire cohort, 1253 subjects died. The hazard ratio for death adjusted for age and sex was 0.71 (95% confidence interval [CI], 0.62-0.81) in occasional exercisers and 0.57 (95% CI, 0.45-0.74) in conditioning exercisers, compared with those who were sedentary (Pfor trend <.001). Among the twin pairs who were healthy at baseline and discordant for death (n=434), the odds ratio for death was 0.66 (95% CI, 0.46-0.94) in occasional exercisers and 0.44 (95% CI, 0.23-0.83) in conditioning exercisers compared with those who were sedentary (P for trend, .005). The beneficial effect of physical activity remained after controlling for other predictors of mortality. CONCLUSION: Leisure-time physical activity is associated with reduced mortality, even after genetic and other familial factors are taken into account.     

Cognitive predictors of medical decision-making capacity in traumatic brain injury.

Objective: To identify cognitive predictors of medical decision-making capacity (MDC) in participants with moderate to severe traumatic brain injury (TBI). Participants: At baseline, participants were 34 adults with TBI and 20 healthy adults. At 6-month follow-up, participants were 24 adults with TBI and 20 healthy adults. Main Outcome Measures: Participants were administered the Capacity to Consent to Treatment Instrument (CCTI) and neuropsychological test measures. Multivariate cognitive predictor models were developed for CCTI consent abilities/standards (S) of understanding (S5); reasoning (S4); and appreciation (S3). Results: At baseline, short-term verbal memory and semantic fluency predicted TBI group performance on understanding (S5); short-term verbal memory and attention predicted performance on reasoning (S4); and working memory predicted performance on appreciation (S3). At 6 month follow-up, executive function, verbal processing speed, and working memory predicted TBI performance on understanding (S5); working memory and short-term memory predicted reasoning (S4); and basic executive functioning predicted appreciation (S3). Conclusions: Multiple cognitive functions are associated with acute impairment and partial recovery of MDC in patients with TBI. Short-term verbal memory predicted consent capacity of TBI participants at the time of acute inpatient hospitalization, while executive functioning and working memory predicted improved capacity at six-month follow-up. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Knowledge growth and maintenance across the life span: The role of print exposure.

One hundred thirty-three college students (mean age?=?19.1 years) and 49 older individuals (mean age?=?79.9 years) completed 2 general knowledge tasks, a vocabulary task, a working memory task, a syllogistic reasoning task, and several measures of exposure to print. A series of hierarchical regression analyses indicated that when measures of exposure to print were used as control variables, the positive relationships between age and vocabulary, and age and declarative knowledge, were eliminated. Within each of the age groups, exposure to print was a significant predictor of vocabulary and declarative knowledge even after differences in working memory, general ability, and educational level were controlled. These results support the theory of fluid-crystallized intelligence and suggest a more prominent role for exposure to print in theories of individual differences in knowledge acquisition and maintenance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stress-related cognitive interference predicts cognitive function in old age.

Both subjective distress and cognitive interference have been proposed as mechanisms underlying the negative effects of stress on cognition. Studies of aging have shown that distress is associated with lower cognitive performance, but none have examined the effects of cognitive interference. One hundred eleven older adults (Mage=80) completed measures of working memory, processing speed, and episodic memory as well as self-report measures of subjective distress and cognitive interference. Cognitive interference was strongly associated with poorer performance on all 3 cognitive constructs, whereas distress was only modestly associated with lower working memory. The results suggest that cognitive process related to stress is an important predictor of cognitive function in advanced age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)