Multiple roads lead to Rome: combined high-intensity aerobic and strength training vs. gross motor activities leads to equivalent improvement in executive functions in a cohort of healthy older adults

The effects of physical activity on cognition in older adults have been extensively investigated in the last decade. Different interventions such as aerobic, strength, and gross motor training programs have resulted in improvements in cognitive functions. However, the mechanisms underlying the relationship between physical activity and cognition are still poorly understood. Recently, it was shown that acute bouts of exercise resulted in reduced executive control at higher relative exercise intensities. Considering that aging is characterized by a reduction in potential energy (V·O2 max − energy cost of walking), which leads to higher relative walking intensity for the same absolute speed, it could be argued that any intervention aimed at reducing the relative intensity of the locomotive task would improve executive control while walking. The objective of the present study was to determine the effects of a short-term (8 weeks) high-intensity strength and aerobic training program on executive functions (single and dual task) in a cohort of healthy older adults. Fifty-one participants were included and 47 (age, 70.7 ± 5.6) completed the study which compared the effects of three interventions: lower body strength + aerobic training (LBS-A), upper body strength + aerobic training (UBS-A), and gross motor activities (GMA). Training sessions were held 3 times every week. Both physical fitness (aerobic, neuromuscular, and body composition) and cognitive functions (RNG) during a dual task were assessed before and after the intervention. Even though the LBS-A and UBS-A interventions increased potential energy to a higher level (Effect size: LBS-A—moderate, UBS-A—small, GMA—trivial), all groups showed equivalent improvement in cognitive function, with inhibition being more sensitive to the intervention. These findings suggest that different exercise programs targeting physical fitness and/or gross motor skills may lead to equivalent improvement in cognition in healthy older adults. Such results call for further investigation of the multiple physiological pathways by which physical exercise can impact cognition in older adults.     

Self-guided strategy-adaption training for older adults: Transfer effects to everyday tasks

ObjectivesThe goal of the present research was to examine the potential of a learner-oriented approach to improving older adults’ performance in tasks that are similar to real-life situations that require strategic deployment of cognitive resources. A crucial element of this approach involves encouraging older adults to explicitly analyze tasks to consider how to adapt trained skills to a new task context. In an earlier study, a specialist-directed intervention produced training gains and transfer to some untrained memory tasks.MethodIn the present study, older adults received a manual instructing them about principles of task analysis, two memory strategies, and strategy adaptation. Self-guided strategy-adaption training involved practicing some memory tasks as well as instructions on how the trained skills could be applied to new tasks that were not practiced. The criterion tasks involved practice tasks, non-practiced tasks that were discussed in the manual, and transfer tasks that were never mentioned in the manual. Two of the tests were from the Everyday Cognition Battery (inductive reasoning and working memory).ResultsAs compared to a waiting-list control group, older adults assigned to self-guided strategy-adaption training showed memory improvements on tasks that were practiced or discussed during training. Most important, the learner-oriented approach produced transfer to the everyday tasks.ConclusionOur findings show the potential of instructing task appraisal processes as a basis for fostering transfer, including improving older adults’ performance in simulated everyday tasks.     

Transfer effects in task-set cost and dual-task cost after dual-task training in older and younger adults: further evidence for cognitive plasticity in attentional control in late adulthood

Older adults' difficulties in performing two tasks concurrently have been well documented (Kramer & Madden, 2008). It has been observed that the age-related differences in dual-task performance are larger when the two tasks require similar motor responses (2001) and that in some conditions older adults also show greater susceptibility than younger adults to input interference (Hein & Schubert, 2004). The authors recently observed that even when the two tasks require motor responses, both older and younger adults can learn to perform a visual discrimination task and an auditory discrimination task faster and more accurately (Bherer et al., 2005). In the present study, the authors extended this finding to a dual-task condition that involves two visual tasks requiring two motor responses. Older and younger adults completed a dual-task training program in which continuous individualized adaptive feedback was provided to enhance performance. The results indicate that, even with similar motor responses and two visual stimuli, both older and younger adults showed substantial gains in performance after training and that the improvement generalized to new task combinations involving new stimuli. These results suggest that dual-task skills can be substantially improved in older adults and that cognitive plasticity in attentional control is still possible in old age.     

Impact on physical fitness on cognitive aging

Cognitive vitality is one of the determining factors of autonomy in the elderly. Aging is often accompanied by important changes in the central nervous system, which may lead to cognitive decline. Several factors seem however to modulate the effect of aging on cognition. For instance, older adults who engage in regular physical activity have better performances in tests implying decision-making process, memory and problems solving. This article draws up a portrait of normal aging while being interested in the impact of the physical fitness on cognition in the elderly. Although further researches are needed to elucidate the mechanisms by which physical fitness enhance cognition in old age, recent studies have shown that improving physical fitness leads to better performances in tasks assessing a diversity of cognitive domains. Moreover, the impact of physical fitness appears to be heterogeneous, being of greater amplitude in tasks that tap executive functions. It thus seems that physical training could serve to enhance and maintain cognitive vitality in older adults.     

Effect of motor practice on dual-task performance in older adults

The aim of this study was to determine the effects of motor practice on cognitive and motor performance in older adults under single- and dual-task conditions. Fourteen younger (19-28 years) and 12 older adults (67-75 years) performed a precision grip sine wave force-tracking and a working memory task under single- and dual-task conditions. Participants performed a pretest, 100 motor practice trials, and a post-test. In the force-tracking and cognitive task, young outperformed older adults. Motor practice improved force-tracking under single- and dual-task conditions for both groups. However, practice did not prevent a decline in motor performance for older adults when they moved from single- to dual-task conditions. After practice, older adults improved cognitive performance in dual-task conditions. Advances in age appear to be associated with a decrease in the ability to manage and coordinate multiple tasks, which remains after extended practice.     

Daily ambulation activity and task performance in community-dwelling older adults aged 63-71 years with preclinical disability

BACKGROUND: The purpose of this study was to examine differences in daily ambulation activity and task modification between community-dwelling older adults above and below an empirically derived physical threshold that has been linked to independence. METHODS: 20 community-dwelling older adults (72.8 +/- 6 years) were categorized into groups based on functional performance using the Continuous scale Physical Functional Performance Test total score (Cs-PFP). Individuals with Cs-PFP > or =57 were assigned to the high functioning group (HIGH; n=10) with all others assigned to the lower functioning group (LOW; Cs-PFP<57; n=10). Dependent variables included steps/day, number of tasks reported with difficulty, and number of tasks reported with modification. RESULTS: HIGH took significantly more steps/day (HIGH: 9503 +/- 4623; LOW: 5048 +/- 2917, p=.019) compared to LOW. Groups reported having difficulty with a similar number of tasks (HIGH: 0.4 +/- 1; LOW: 1.0 +/- 1, p=.092) but LOW reported modifying a significantly larger number of tasks (HIGH: 0.3 +/- 1; LOW 1.4 +/- 1, p=.049). CONCLUSIONS: Older adults with preclinical disability have reduced daily ambulatory activity compared to older adults with high function despite a similar independent living status. Individuals compensate for reduced physical reserves by modifying the method of performing a task. Identifying early declines in physical ability through task modification and daily ambulation will provide the opportunity for timely intervention to older adults desiring to remain independent within a community-dwelling environment.     

Differences between two types of dual tasks according to the educational level in older adults

IntroductionFor dual-task paradigms, the timed up and go (TUG) test along with other cognitive or motor tasks has been used to evaluate and predict the risk of falling in older adults. However, the interference between motor-cognitive tasks can differ by the cognitive task.ObjectiveTo evaluate the performance of the TUG test under a single task condition and two dual-task conditions in older adults and to explore the effect of educational level on task performance.MethodsA total of 418 older adults (328 females) voluntarily participated in this study. The TUG test was administered as a single task and a dual task with one secondary simultaneous task: counting aloud backward from 100 or naming animals. Comparisons were performed to determine the interference caused by each cognitive task on the motor task, and correlation analysis was performed to explore the role of educational level.ResultsThe animal task led to a poorer TUG performance and a higher dual-task cost than did the counting task. Furthermore, the motor task led to a higher percentage of errors and cognitive stops in the animal task. Educational level plays a significant role in the interaction between tasks.ConclusionsBetween-task interference differs by the type of cognitive task performed and the educational level of the participants. The results of the present study should be considered when dual-task assessments are planned for older adults.     

Aerobic exercise training increases brain volume in aging humans

BACKGROUND: The present study examined whether aerobic fitness training of older humans can increase brain volume in regions associated with age-related decline in both brain structure and cognition. METHODS: Fifty-nine healthy but sedentary community-dwelling volunteers, aged 60-79 years, participated in the 6-month randomized clinical trial. Half of the older adults served in the aerobic training group, the other half of the older adults participated in the toning and stretching control group. Twenty young adults served as controls for the magnetic resonance imaging (MRI), and did not participate in the exercise intervention. High spatial resolution estimates of gray and white matter volume, derived from 3D spoiled gradient recalled acquisition MRI images, were collected before and after the 6-month fitness intervention. Estimates of maximal oxygen uptake (VO2) were also obtained. RESULTS: Significant increases in brain volume, in both gray and white matter regions, were found as a function of fitness training for the older adults who participated in the aerobic fitness training but not for the older adults who participated in the stretching and toning (nonaerobic) control group. As predicted, no significant changes in either gray or white matter volume were detected for our younger participants. CONCLUSIONS: These results suggest that cardiovascular fitness is associated with the sparing of brain tissue in aging humans. Furthermore, these results suggest a strong biological basis for the role of aerobic fitness in maintaining and enhancing central nervous system health and cognitive functioning in older adults.     

The relationships among pulmonary function, aerobic fitness, and cognitive functioning in older COPD patients.

STUDY OBJECTIVES: To study the predictive relationships among age, pulmonary function, aerobic fitness, and cognition in people with COPD. DESIGN: Observational study conducted during baseline testing with COPD patients who volunteered to participate in an exercise intervention. PARTICIPANTS: Older adults (age, 56 to 80 years) with COPD. MEASUREMENTS AND RESULTS: Age, depression, education level, aerobic fitness, blood oxygen saturation levels, and pulmonary function were assessed. Participants were randomly assigned to take cognitive tests of (1) fluid intelligence, (2) processing speed and working memory span, or (3) processing speed and inhibition. After controlling for education and depression (F(2,57) = 7.43; r(2) = 0. 21), performance on the 6-min walk (F(1,56) = 15.27; r(2) = 0.17) and age (F(1,55) = 7.52; r(2) = 0.08) were significant predictors of fluid intelligence. On the speed-of-processing task, performance on the 6-min walk (F(1,30) = 8.17; r(2) = 0.20), maximum voluntary ventilation (F(1,29) = 5.81; r(2) = 0.16), and age (F(1,28) = 5.26; r(2) = 0.10) were significant predictors. FVC was a significant predictor (F(1,25) = 6.37; r(2) = 0.18) of working memory span. The ability to inhibit a response was not significantly predicted by any of the variables assessed. CONCLUSIONS: In an older COPD sample, age, aerobic fitness, and pulmonary function are predictive of cognitive performance on various tasks. In particular, age and aerobic fitness are predictive of speed of processing, which is a cognitive variable that may itself underlie performance on a majority of cognitive tasks.     

Aging and memory for self-performed tasks: effects of task difficulty and time pressure

An increase in task difficulty or time pressure during the performance of cognitive tasks decreased the ability of older adults to recall the tasks. In Experiments 1 and 2, adult age differences in recall of cognitive tasks were smaller for easier than for more difficult tasks, and, in Experiment 3, adult age differences were smaller for recall of cognitive tasks without time pressure than for recall of cognitive tasks with time pressure. During difficult or time-pressured cognitive tasks, older adults may become anxious about their performance, and they may have trouble inhibiting negative self-evaluative thoughts about their performance. Older adults may thus devote less attention to aspects of the cognitive tasks that would be beneficial for task recall.     

Simultaneously measuring gait and cognitive performance in cognitively healthy and cognitively impaired older adults: the Basel motor-cognition dual-task paradigm

OBJECTIVES: To investigate dual‐task performance of gait and cognition in cognitively healthy and cognitively impaired older adults using a motor–cognition dual‐task paradigm. DESIGN: Cross‐sectional retrospective study. SETTING: The Basel Memory Clinic and the Basel Study on the Elderly (Project BASEL). PARTICIPANTS: Seven hundred eleven older adults (mean age 77.2 ± 6.2, 350 (49.2%) female and 361 (50.8%) male). MEASUREMENTS: Gait velocity and cognitive task performance using a working memory (counting backward from 50 by 2s) and a semantic memory (enumerating animal names) task were measured during single‐ and dual‐task conditions. Gait was assessed using the GAITRite electronic walkway system. Cognitive impairment was defined as a score less than 25 on the Mini‐Mental State Examination. RESULTS: During dual tasks, participants reduced gait velocity (P<.001) and calculated fewer numbers (P=.03) but did not enumerate fewer animals and did not make more errors or repetitions (P>.10). Cognitively impaired individuals had lower baseline gait velocity and a greater reduction in gait velocity but not cognitive performance during dual tasks than cognitively healthy participants (P<.01). CONCLUSION: Gait velocity was lower during both dual tasks, whereas decrease in cognitive performance depended on the cognitive ability needed in the dual‐task condition. Cognitively impaired individuals generally have poorer baseline performance and greater dual task–related gait velocity reduction than those who are cognitively healthy. Future research should include different conditions for gait to determine adaptive potentials of older adults.     

Attentional abilities and functional outcomes following stroke

Although stroke affects cognitive functioning as well as motor functioning, research on cognitive consequences has lagged behind that focused on motor function. The evidence that is accruing suggests that cognitive function is importantly related to successful rehabilitation. The present study examined two aspects of attentional functioning (divided attention and switching attention) in older adult stroke survivors and healthy older adults. In addition, the authors investigated the relation between attention and functional outcomes following stroke. Results revealed stroke-related deficits in both of the types of attention as well as significant associations between attentional functioning and both physical and social outcome measures. Poorer attentional performance was associated with a more negative impact of stroke on daily functioning. These findings suggest an important role for attention in post-stroke function and provide information that can contribute to improving outcomes following stroke.     

Association of executive function and performance of dual-task physical tests among older adults: analyses from the InChianti study

BACKGROUND: previous studies have reported an association between cognitive function and physical performance, particularly among older adults. OBJECTIVE: to examine the association between executive function and performance difference on complex versus usual walking tasks in a sample of non-demented older adults. DESIGN: population-based epidemiological study of older people residing in the Chianti area (Tuscany, Italy). PARTICIPANTS: 737 community-dwelling individuals aged 65 years and older. METHODS: gait speed (m/s) was measured during the performance of complex walking tasks (walking/talking, walking/picking-up an object, walking/carrying a large package, walking over obstacles, walking with a weighted vest) and reference walking tasks (7 m usual pace, 7 m fast pace and 60 m fast pace). Executive function was assessed using the Trail Making Test (TMT). Other measures included Mini-Mental State Examination (MMSE), sociodemographic characteristics and selected physiological impairments. RESULTS: gait speed for the selected reference and complex walk tasks was consistently lower among participants with poor executive function. Per cent decline in gait speed compared with the reference task differed by executive function for certain tasks (e.g. walking/obstacles: 30 versus 24% decline in low versus high executive function respectively, P = 0.0006) but not for others. CONCLUSIONS: poor executive function is associated with measures of gait, including specific challenges. Overall, the results showed that the cost associated with the addition of a challenge to the basic walking task differs by executive function and the nature of the task. Further research is needed to determine whether improvement in executive function abilities translates to better performance on selected complex walking tasks.     

Low cognitive performance,comorbid disease,and task-specific disability: findings from a nationally representative survey

BACKGROUND: This research evaluated the association of low cognitive performance with both chronic diseases and conditions, and with difficulties in a broad array of task-specific functioning and disability measures in older adults living in the community. METHODS: Data were from the first wave of the Assets and Health Dynamics Among the Oldest-Old Study, a national panel survey of individuals age 70 and older (n = 6600 age-eligible self-respondents). Low cognitive performance (LCP) was defined as scores in the lowest (poorest performing) 25th percentile of a cognitive performance scale. The associations of LCP with prevalent chronic diseases and conditions and with limitations in 14 tasks (strength and mobility, instrumental activities of daily living, and activities of daily living) were evaluated. Associations of LCP and task limitations were adjusted for potential modifiers and confounders, including demographic characteristics (age, gender, race), educational attainment, chronic diseases, depressive symptoms, and sensory impairments. Data were weighted to account for complex sample design and nonresponse. RESULTS: More than one third of people with LCP had three or more coexisting diseases and conditions. The unadjusted associations of LCP with task functioning were attenuated after covariate adjustment, but even after adjustment, LCP remained significantly and independently associated with functioning problems in 9 of 14 tasks (borderline with four more), including mobility tasks. CONCLUSIONS: Low cognitive performance, regardless of its relationship to clinical dementia, coexists with multiple chronic diseases and conditions. It is independently associated with a broad array of functioning difficulties, even after controlling for demographic characteristics, educational attainment, and chronic conditions. Chronic diseases and conditions, however, attenuate the relationship between LCP and some task difficulties. LCP should be considered an important comorbid condition associated with both chronic diseases and disability that substantially increases the health burden of many older adults who are poorly equipped to handle it.     

Aerobic fitness reduces brain tissue loss in aging humans

BACKGROUND: The human brain gradually loses tissue from the third decade of life onward, with concomitant declines in cognitive performance. Given the projected rapid growth in aged populations, and the staggering costs associated with geriatric care, identifying mechanisms that may reduce or reverse cerebral deterioration is rapidly emerging as an important public health goal. Previous research has demonstrated that aerobic fitness training improves cognitive function in older adults and can improve brain health in aging laboratory animals, suggesting that aerobic fitness may provide a mechanism to improve cerebral health in aging humans. We examined the relationship between aerobic fitness and in vivo brain tissue density in an older adult population, using voxel-based morphometric techniques. METHODS: We acquired high-resolution magnetic resonance imaging scans from 55 older adults. These images were segmented into gray and white matter maps, registered into stereotaxic space, and examined for systematic variation in tissue density as a function of age, aerobic fitness, and a number of other health markers. RESULTS: Consistent with previous studies of aging and brain volume, we found robust declines in tissue densities as a function of age in the frontal, parietal, and temporal cortices. More importantly, we found that losses in these areas were substantially reduced as a function of cardiovascular fitness, even when we statistically controlled for other moderator variables. CONCLUSIONS: These findings extend the scope of beneficial effects of aerobic exercise beyond cardiovascular health, and they suggest a strong solid biological basis for the benefits of exercise on the brain health of older adults.     

Does practice modify the relationship between postural control and the execution of a secondary task in young and older individuals?

BACKGROUND: Numerous daily activities require performing more than one task simultaneously, such as standing while engaging in a conversation. Recent studies have shown that postural control may be degraded when individuals are asked to perform a secondary task and that this effect seems to be more pronounced in older adults. Since various types of secondary tasks have been used in postural control studies, the novelty of the tasks may partly explain why dual-task interference occurs. It is known that novel tasks require greater attentional resources and thus may interfere to a greater extent with the performance of another task. Therefore, by practicing this dual-task situation, interference could perhaps be diminished. Since the dual-tasking efficiency is reduced with aging, practice could be very beneficial to older adults. OBJECTIVES: The main goal of this study was to examine whether practice could modify the changes seen in postural sway when individuals are asked to perform a secondary task while maintaining upright stance and whether older individuals could benefit to a greater extent from practice than would young individuals. The second goal was to examine the dual-task performance in young versus older adults and to determine whether older individuals benefit equally or to a greater extent from practice as compared with young individuals. METHODS: Young and older individuals were asked to stand on a force platform while performing a secondary task or no task. The secondary task condition was repeated six times to examine the effects of practice. RESULTS: Practice did not modify the performance of postural sway, but did lead to an increase in speed of execution of the secondary task for both groups equally. In young participants, the amplitude of sway was decreased, and the frequency of sway was increased, indicating an increased stiffness when performing the cognitive task. Older participants showed increased amplitude of sway and increased frequency of sway in the mediolateral direction only. CONCLUSIONS: Since the dual-task condition was only repeated six times, it could be hypothesized that the effect of practice would be greater, if more trials were added or if more practice sessions were included. More research is needed to verify this hypothesis.     

Effects of once weekly dual‐task training in older adults: A pilot randomized controlled trial

Aim: To compare single‐task and dual‐task training on obstacle avoidance, gait speed and balance in healthy community‐dwelling older adults. Methods: A total of 17 older adults (65–83 years) participated in a group circuit class, once weekly for 45 min for 4 weeks. The dual‐task group carried out cognitive activities simultaneously with gait and balance exercises. The single‐task training group carried out identical gait and balance activities without cognitive tasks. We assessed time to complete a 6‐m obstacle course under single‐task and three different dual‐task conditions (spontaneous speech, alphabet recitation and coin transfer), 25‐ft gait speed, Timed Up and Go, and the Activities‐specific Balance Confidence Scale. Results: Both groups showed significant improvement in gait speed and Timed Up and Go. In addition, the proportion of participants who achieved gait speed >1.0 m/s increased in both groups. There were no within‐ or between‐subjects differences in obstacle course performance under single or dual‐task conditions after the intervention. Conclusion: Once weekly group circuit training focusing on balance, gait and agility, with or without simultaneous cognitive tasks, resulted in significantly improved walking speed among older adults. Group‐format dual‐task training once per week did not improve walking time or dual‐task cost on an obstacle negotiation task. Geriatr Gerontol Int 2012; ??: ??–??.     

B vitamins, cognition, and aging: a review.

Recent research has highlighted the potential impact of nutritional factors and individual micronutrients on the brain and on cognitive performance, especially in older adults. The B vitamins, folate, B12, and B6, are of particular interest because even subclinical deficiencies in these vitamins are thought to be relatively common in the general population and in older adults in particular. Recent cross-sectional and longitudinal studies have provided evidence for an association between these B vitamins and many aspects of cognitive performance and have raised the possibility that even subclinical differences in nutritional status may have a subtle influence on aspects of cognitive performance, especially in older adults and in clinical populations. Preliminary evidence also indicates the effectiveness of supplementation in enhancing cognitive performance in older adults. Important considerations for future research include the use of placebo-controlled intervention studies, sensitive outcome measures of cognitive performance, and exploration of bioavailability and dose-response relationships.     

Divided attention in older but not younger adults is impaired by anxiety

It has been hypothesized that the disruptive effects of negative emotional states, such as anxiety and depression, may contribute to poorer performance in older age. Some studies have reported that higher levels of anxiety are associated with poorer cognitive performance in older adults but not younger adults. The author examined if age and anxiety interact with performance by comparing the performance of normal healthy younger and older adults on cognitive and motor tests under conditions of selective and divided attention. Ninety-two older adults (mean age=70.1 years, SD=7.1 years) and 78 younger adults (mean age=18.8 years, SD=1.9 years), matched on education, vocabulary, and self-reported health, performed a word-comparison and pursuit-rotor task under conditions of selective and divided attention. Anxiety was assessed using the Speilberger State-Trait anxiety scale. The hypothesis was supported: higher anxiety was associated with poorer divided attention performance in older, but not younger, adults. Anxiety was not associated with poorer motor performance in older adults. Implications of the results for cognitive-resource theories of aging cognition are discussed.