The effects of typical ageing on cognitive control: recent advances and future directions

Cognitive control is one of the most fundamental aspects of human life. Its ageing is an important contemporary research area due to the needs of the growing ageing population, such as prolonged independence and quality of life. Traditional ageing research argued for a global decline in cognitive control with age, typically characterised by slowing processing speed and driven by changes in the frontal cortex. However, recent advances questioned this perspective by demonstrating high heterogeneity in the ageing data, domain-specific declines, activity changes in resting state networks, and increased functional connectivity. Moreover, improvements in neuroimaging techniques have enabled researchers to develop compensatory models of neural reorganisation that helps negate the effects of neural losses and promote cognitive control. In this article on typical ageing, we review recent behavioural and neural findings related to the decline in cognitive control among older adults. We begin by reviewing traditional perspectives and continue with how recent work challenged those perspectives. In the discussion section, we propose key areas of focus for future research in the field.

Cognitive Effects of a Cognitive Stimulation Programme on Trained Domains in Older Adults with Subjective Memory Complaints: Randomised Controlled Trial

Age-related subjective memory complaints (SMC) are a common concern among older adults. However, little is known about the effects of cognitive stimulation (CS) interventions on subjective memory complaints. The aim of this study was to analyse the effectiveness of a CS programme on global cognition and cognitive functions of older adults with SMC. A randomised clinical trial was conducted on older adults with SMC, including 308 participants ≥65 years of age assessed 6 and 12 months after the intervention. The assessment instrument was the Spanish version of the Mini-Mental State Examination (MEC-35), and all domains of the instrument were assessed. For statistical analysis, the data were analysed using robust ANOVA with means truncated at 20% utilising a two-way repeated measures model, with between (groups) and within (measurements) factors. In post hoc tests, a Wilcoxon signed-rank test of exact permutations between groups and Bonferroni correction were applied. In post hoc between-group tests, significant differences were found: (1) post-treatment in MEC-35, temporal orientation, short-term memory (STM), global language and praxis, and language and praxis (p ≤ 0.005); (2) at 6 months in MEC-35, global orientation, temporal orientation, and STM (p = 0.005); (3) at 12 months in MEC-35, global orientation, temporal orientation, STM, global language and praxis, and language (p = 0.005). This study shows benefits in global cognition and orientation, temporal orientation, STM, and language in older adults with SMC.

Exercise Training Improves Memory Performance in Older Adults: A Narrative Review of Evidence and Possible Mechanisms

As human life expectancy increases, cognitive decline and memory impairment threaten independence and quality of life. Therefore, finding prevention and treatment strategies for memory impairment is an important health concern. Moreover, a better understanding of the mechanisms involved underlying memory preservation will enable the development of appropriate pharmaceuticals drugs for those who are activity limited. Exercise training as a non-pharmacological tool, has been known to increase the mean lifespan by maintaining general body health and improving the cardiovascular and nervous systems function. Among different exercise training protocols, aerobic exercise has been reported to prevent the progression of memory decline, provided adequate exertion level, duration, and frequency. Mechanisms underlying exercise training effects on memory performance have not been understood yet. Convergent evidence suggest several direct and indirect mechanisms at molecular and supramolecular levels. The supramolecular level includes improvement in blood circulation, synaptic plasticity and neurogenesis which are under controls of complex molecular signaling of neurotransmitters, neurotrophic factors, exerkines, and epigenetics factors. Among these various factors, irisin/BDNF signaling seems to be one of the important mediators of crosstalk between contracted skeletal muscles and the brain during exercise training. This review provides an affordable and effective method to improve cognitive function in old ages, particularly those who are most vulnerable to neurodegenerative disorders.

Few Structural Brain Changes Associated With Moderate-Intensity Interval Training and Low-Intensity Continuous Training in a Randomized Trial of Fitness and Older Adults

This study utilized a randomized control trial to examine whether structural changes in the precuneus, insula, caudate, hippocampus, and putamen were related to exercise. A total of 197 healthy older adults with no evidence of dementia participated in moderate-intensity interval training or low-intensity continuous training for 16 weeks. Size decreased in the right hippocampus such that the effect of time was significant but the interaction with condition was not. For the left hippocampus, size decreased in the low-intensity continuous training condition but increased in the moderate-intensity continuous training plus interval training condition at the trend level. Finally, there was a significant time-by-condition interaction such that the thickness of the left insula increased for low-intensity continuous training and decreased for moderate-intensity continuous training plus interval training. Few structural changes were associated with the exercise intervention. Future studies should examine the effects of exercise on brain structure in high-risk or clinical populations for a longer period of time.

The influence of a 16-week exercise program, APOE status, and age on executive function task performance: A randomized trial

Previous research has shown beneficial cognitive changes following exercise training in older adults. However, the work on the potential moderating effects of Apoliprotein E (APOE) ε4 carrier status has been mixed, and the role of exercise intensity remains largely unexplored. The present study sought to examine the influence of APOE ε4 status and exercise intensity on measures of cognitive performance in a group of older adults. Cross-sectional comparisons between a group of younger inactive adults (n = 44, age = 28.86 ± 0.473 SD, 60.5% female) and a group of older inactive adults (n = 142, age = 67.8 ± 5.4, 62.7% female) were made on baseline measurements of APOE ε4 status, VO₂peak, and cognitive performance in the domain of executive functioning. The older adults also participated in a randomized controlled exercise trial, exercising three times per week for 16-weeks in either a low-intensity continuous training (LICT) group or a moderate-intensity continuous training plus interval training (MICT+IT) group at the Center for Health and Neuroscience, Genes, and Environment (CUChange) Exercise Laboratory. Follow-up measurements of VO₂peak and cognitive performance were collected on the older adults after the exercise intervention. Cross-sectional comparisons between the older and younger adults demonstrated significant impairments among older adults in Stroop effect on error and time, Category Switch mixing effects, and Keep Track task. This impairment was not moderated by APOE ε4 carrier status. Improvements from pre- to post-exercise intervention were observed in both exercise groups in Stroop effect on error ([F (1, 256) = 9.381, p < 0.01, η² = 0.031]) and Category Switch switching effect reaction time ([F(1, 274) = 4.442, p < 0.05, η² = 0.020]), with no difference between exercise groups. The moderating effects of APOE ε4 carrier status were mixed. Exercise did not improve the Stroop effect on error among ε4 carriers assigned to MICT+IT when improvements were seen in all other groups. Further research is needed to examine the mechanisms of action by which exercise impacts cognitive task performance, and possible moderators such as genetic variability and exercise intensity.

A three-armed cognitive-motor exercise intervention to increase spatial orientation and life-space mobility in nursing home residents: study protocol of a randomized controlled trial in the PROfit project

Background

In nursing home residents, the combination of decreasing mobility and declining cognitive abilities, including spatial orientation, often leads to reduced physical activity (PA) and life-space (LS) mobility. As a consequence of sedentary behavior, there is a lack of social interaction and cognitive stimulation, resulting in low quality of life. It has not yet been examined whether cognitive-motor training including spatial cognitive tasks is suitable to improve spatial orientation and, as a consequence, to enlarge LS mobility, and increase well-being and general cognitive-motor functioning. Therefore, the overall goal of this multicentric randomized controlled trial (RCT) is to compare the effect of three different intervention approaches including functional exercise and orientation tasks on PA, LS and spatial orientation in nursing home residents.

Methods

A three-arm single-blinded multicenter RCT with a wait-list control group will be conducted in a sample of 513 individuals (needed according to power analysis) in three different regions in Germany. In each nursing home, one of three different intervention approaches will be delivered to participating residents for 12 weeks, twice a week for 45 min each: The PROfit basic group will perform functional strength, balance, flexibility, and walking exercises always at the same location, whereas the PROfit plus group changes the location three times while performing similar/the same exercises as the PROfit basic group. The PROfit orientation group receives navigation tasks in addition to the relocation during the intervention. Physical and cognitive functioning as well as psychological measures will be assessed in all study groups at baseline. Participants will then be randomized into either the intervention group or the wait-list control group. After 12 weeks, and after 24 weeks the measures will be repeated.

Discussion

This study evaluates whether the three different interventions are feasible to reduce the decline of or even improve PA, LS, and spatial orientation in nursing home residents. By adding different training locations in PROfit plus, the program is expected to be superior to PROfit basic in increasing physical and cognitive parameters. Moreover, we expect the PROfit orientation intervention to be most effective in terms of PA, LS, and spatial orientation due to two mechanisms: (1) increased physical and cognitive activity will enhance cognitive-motor capacity and (2) the spatial training will help to build up cognitive strategies to compensate for age-related loss of spatial orientation abilities and related limitations.

Trial registration

The trial was prospectively registered at DRKS.de with registration number DRKS00021423 on April 16, 2020 and was granted permission by the Technical University Berlin local ethics committee (No. GR_14_20191217).

The Downsides of Cognitive Enhancement

Cognitive enhancement is becoming progressively popular as a subject of scientific investigation and by the public, although possible adverse effects are not sufficiently understood. We call for cognitive enhancement to build on more specific, mechanistic theories given that a-theoretical approaches to cognitive enhancement are both a cause and a consequence of a strong, if not exclusive focus on the benefits of procedures suited to enhance human cognition. We focus on downsides of cognitive enhancement and suggest that every attempt to enhance human cognition needs to deal with two basic principles: the neuro-competition principle and the nonlinearity principle. We discuss the possibility of both principles in light of recent attempts to improve human cognition by means of transcranial direct current stimulation, a well-established brain stimulation method, and clinically relevant nootropic drugs. We propose that much stronger emphasis on mechanistic theorizing is necessary in guiding future research on both the upsides and the downsides of cognitive enhancement.

Most evidence for the compensation account of cognitive training is unreliable

Cognitive training and brain stimulation studies have suggested that human cognition, primarily working memory and attention control processes, can be enhanced. Some authors claim that gains (i.e., post-test minus pretest scores) from such interventions are unevenly distributed among people. The magnification account (expressed by the evangelical “who has will more be given”) predicts that the largest gains will be shown by the most cognitively efficient people, who will also be most effective in exploiting interventions. In contrast, the compensation account (“who has will less be given”) predicts that such people already perform at ceiling, so interventions will yield the largest gains in the least cognitively efficient people. Evidence for this latter account comes from reported negative correlations between the pretest and the training/stimulation gain. In this paper, with the use of mathematical derivations and simulation methods, we show that such correlations are pure statistical artifacts caused by the widely known methodological error called “regression to the mean”. Unfortunately, more advanced methods, such as alternative measures, linear models, and control groups do not guarantee correct assessment of the compensation effect either. The only correct method is to use direct modeling of correlations between latent true measures and gain. As to date no training/stimulation study has correctly used this method to provide evidence in favor of the compensation account, we must conclude that most (if not all) of the evidence should be considered inconclusive.

Visual search task immediate training effects on task-related functional connectivity

Brain plasticity occurs over the course of the human lifetime. Learning and training modify our neuronal synapses and adapt our brain activity, from priming effects in modal areas to higher-order changes in the association cortex. The current state of the art suggests that learning and training effects might induce large-scale brain connectivity changes. Here, we used task-fMRI data and graph-based approaches to study the immediate brain changes in functional connections associated with training on a visual search task, and the individual differences in learning were studied by means of brain-behavior correlations. In a previous work, we found that trained participants improved their response speed on a visual search task by 31%, whereas the control group hardly changed. In the present study, we showed that trained individuals changed regional connections (local links) in cortical areas devoted to the specific visual search processes and to areas that support information integration, and largely modified distributed connections (distant links) linking primary visual areas to specific attentional and cognitive control areas. In addition, we found that the individuals with the most enhanced connectivity in the dorsolateral prefrontal cortex performed the task faster after training. The observed behavioral and brain connectivity findings expand our understanding of large-scale dynamic readjustment of the human brain after learning experiences.

WOME: Theory-Based Working Memory Training - A Placebo-Controlled, Double-Blind Evaluation in Older Adults

Background: Scientifically evaluated cognitive intervention programs are essential to meet the demands of our increasingly aging society. Currently, one of the “hottest” topics in the field is the improvement of working memory function and its potential impact on overall cognition. The present study evaluated the efficacy of WOME (WOrking MEmory), a theory-based working memory training program, in a double-blind, placebo-controlled, and randomized controlled trial (www.drks.de, DRKS00013162).

Methods:N = 60 healthy older adults were allocated to (1) the WOME intervention, (2) an active low-level intervention, or (3) a passive control group. Overall, the intervention groups practiced twelve sessions of 45 min within 4 weeks of their respective training. Transfer effects were measured via an extensive battery of neuropsychological tests and questionnaires both pre-/post-training and at a 3-month follow-up.

Results:WOME led to a significant improvement in working memory function, demonstrated on a non-trained near transfer task and on two different composite scores with moderate to large effect sizes. In addition, we found some indication of relevant impact on everyday life. The effects were short-term rather than stable, being substantially diminished at follow-up with only little evidence suggesting long-term maintenance. No transfer effects on other cognitive functions were observed.

Conclusion:WOME is an appropriate and efficient intervention specifically targeting the working memory system in healthy older adults.

Trial Registration: German Clinical Trials Register (DRKS), Identifier: DRKS00013162.

More expertise for a better perspective: Task and strategy-driven adaptive neurofunctional reorganization for word production in high-performing older adults

The suggestion that neurofunctional reorganization may contribute to preserved language abilities is still emerging in aging studies. Some of these abilities, such as verbal fluency (VF), are not unitary but instead rely on different strategic processes that are differentially changed with age. Younger (n = 13) and older adults (n = 13) carried out an overt self-paced semantic and orthographic VF tasks within mixed fMRI design. Our results suggest that patterns of brain activation sustaining equivalent performances could be underpinned by different strategies facing brain changes during healthy aging. These main findings suggest that temporally mediated semantic clustering and frontally mediated orthographic switching were driven by evolutive neurofunctional resources in high-performing older adults. These age-related activation changes can appear to be compatible with the idea that unique neural patterns expressing distinctive cognitive strategies are necessary to support older adults' performance on VF tasks.

Cognitive Aging: Activity Patterns and Maintenance Intentions

This study examined relationships between cognitive functioning in older people and 1) levels of mental, physical and social activities, and 2) intentions regarding maintenance of cognitive functioning. Participants ( N = 145) were 70–91 years of age, varied in health status and socio-economic backgrounds. Current cognitive functioning was assessed by psychometric tests and real world problem solving tasks. Crystallized ability was indexed by the National Adult Reading Test (NART). Degree of involvement in mentally demanding activities was positively related to a fluid cognitive factor after effects of age, prior functioning, gender, health, and socio-economic status were accounted for. Social and physical activities were not related to the cognitive measures. Age effects on cognitive functioning were reduced among participants who reported undertaking activities intentionally to maintain cognitive functioning.

Mental Exercise and Mental Aging: Evaluating the Validity of the "Use It or Lose It" Hypothesis

It is widely believed that keeping mentally active will prevent age-related mental decline. The primary prediction of this mental-exercise hypothesis is that the rate of age-related decline in measures of cognitive functioning will be less pronounced for people who are more mentally active, or, equivalently, that the cognitive differences among people who vary in level of mental activity will be greater with increased age. Although many training studies, and comparisons involving experts, people in specific occupations, and people whose mental activity levels are determined by their self-reports, have found a positive relation between level of activity and level of cognitive functioning, very few studies have found an interactive effect of age and mental activity on measures of cognitive functioning. Despite the current lack of empirical evidence for the idea that the rate of mental aging is moderated by amount of mental activity, there may be personal benefits to assuming that the mental-exercise hypothesis is true.

Diferenças nos aspectos cognitivos entre idosos praticantes e não praticantes de exercício físico

Objetivo Comparar o desempenho cognitivo de idosos praticantes e não praticantes de exercícios físicos. Métodos Este estudo transversal foi realizado com 104 idosos, sendo 64 pertencentes ao Grupo Praticantes de exercícios físicos (G1) e 40 pertencentes ao Grupo não Praticantes (G2), cadastrados em Centros de Saúde. Foram aplicados o Miniexame de Estado Mental (MEEM) para avaliar o estado cognitivo e uma ficha para caracterização da amostra. Posteriormente, aplicou-se a Bateria de Avaliação Cognitiva Computadorizada (CogState) para avaliação do desempenho cognitivo dos idosos. Utilizaram-se o teste U Mann-Whitney para comparação dos grupos e o cálculo da medida de efeito d de Cohen, para verificar se a prática de exercício físico influencia no desempenho cognitivo. Para análise descritiva, utilizaram-se dados expressos em média, desvio-padrão, mediana e percentil. Admitiu-se nível de significância de 5%. Resultados A pontuação no MEEM apresentou diferença estatisticamente significativa entre grupos. Quanto ao desempenho cognitivo, medido pelo CogState, os grupos diferiram significativamente para todas as variáveis analisadas, apresentando o G1 o melhor desempenho nos testes de tempo de reação simples, de escolha e de atenção assistida; já o G2 obteve melhor desempenho nos testes de memória de curto prazo e de trabalho. Conclusões Idosos praticantes de exercícios físicos demonstram possuir melhor desempenho para o tempo de reação simples, tempo de reação de escolha e atenção assistida, quando comparados aos idosos não praticantes.

Effects of working memory training in young and old adults

Many cognitive abilities, including working memory and reasoning ability, decline with progressing age. In this study, we investigated whether four weeks of intensive working memory training would enhance working memory and reasoning performance in an age-comparative setting. Groups of 34 young (19-36 years) and 27 older (62-77 years) adults practiced tasks representing the three functional categories in the facet model of working memory capacity: storage and processing, relational integration, and supervision. The data were compared to those of a young and an old active control group who practiced tasks with low working memory demands. A cognitive test battery measuring near and far transfer was administered before and after training. Both age groups showed increased working memory performance in the trained tasks and in one structurally similar, but nontrained, task. Young adults also improved in a task measuring word-position binding in working memory. However, we found no far transfer to reasoning in either age group. The results provide evidence that working memory performance can be improved throughout the life span. However, in contrast to a previous study in which each facet of working memory capacity was trained separately, the present study showed that training multiple functional categories simultaneously induces less transfer.

Requirements of older adults for a daily use of an internet-based cognitive training platform

A decline of cognitive abilities is a part of normal human ageing. However, recent research has demonstrated that an enriched environment can have a beneficial impact on cognitive function in old age. Accordingly, mentally and socially active lifestyles are associated with less cognitive decline in old age. Specific interventions such as computerized cognitive training programs for older adults are also known to have a positive effect on the level of cognitive functioning. Therefore, online platforms combining cognitive training with web 2.0 features may yield multiple benefits for older users. However, to date only little research exists on technological acceptance and media use in this age-group especially for cognitively-impaired seniors. Therefore, in order to assess specific preferences and potential barriers of older adults regarding a web-based platform for cognitive training, we conducted qualitative interviews with 12 older adults. Half of the participants were diagnosed with mild cognitive impairment (MCI). Most importantly, our results show that cognitive exercises should incorporate themes and topics older adults are interested in. Additional communication features could serve as ideal methods for increasing user motivation. Furthermore, we derived eight critical requirements of older adults concerning daily use of a web-based cognitive training platform. Implications for future research and development are discussed.

Speed of processing training in the ACTIVE study: how much is needed and who benefits?

OBJECTIVES

Cognitive training has been shown to improve both cognitive and everyday abilities in older adults; however, little is known concerning the amount of training needed or the characteristics of those who benefit. These analyses examined the longitudinal impact of dosage (number of training sessions) on the improvement and maintenance of cognitive and everyday function.

METHODS

ACTIVE is a longitudinal, randomized, single-blind clinical trial evaluating cognitive interventions in older adults (aged 65-94) from six states in the United States.

RESULTS

Latent growth curve models indicated that initial training effects were maintained over 5 years and amplified by booster sessions. A single booster session counteracted 4.92 months of age-related processing speed decline.

DISCUSSION

Cognitive performance improved by 2.5 standard deviations for participants who attended all 10 initial sessions and all 8 booster sessions compared to randomized participants who attended none. Implications for the broader application of cognitive training interventions are discussed.

Reasoning training in the ACTIVE study: how much is needed and who benefits?

OBJECTIVE

To characterize change through 5-year follow-up, associated with training, booster, adherence, and other characteristics.

METHODS

Sample included all individuals randomly assigned to reasoning training (N = 699). Piecewise latent growth modeling was used to examine trajectory of performance on outcome measures.

RESULTS

Training resulted in improved reasoning performance through Year 5. A significant third annual booster effect was one-half the size of the training effect. Training adherence resulted in greater training effects. Higher education, Mini-Mental State Exam (MMSE), better health, and younger age related to higher baseline performance. Higher MMSE was related to larger training effects, larger linear slopes, and smaller booster effects. Significant functional outcomes included a training effect for complex reaction time (CRT), and first annual booster effects for the CRT and observed tasks of daily living.

DISCUSSION

Initial training gain was comparable with magnitude of age-related cognitive decline over 5 years with no training. Neither age nor gender predicted training or booster effects, indicating the generality of training effects across age (65-90 years).

Longitudinal effects of physical activity on self-efficacy and cognitive processing of active and sedentary elderly women

Previous studies support that regular physical activity in aging contributes as a protective factor against cognitive decline and improves mood states. However, there is a lack of longitudinal studies in this area.

Effects and mechanisms of working memory training: a review

Can cognitive abilities such as reasoning be improved through working memory training? This question is still highly controversial, with prior studies providing contradictory findings. The lack of theory-driven, systematic approaches and (occasionally serious) methodological shortcomings complicates this debate even more. This review suggests two general mechanisms mediating transfer effects that are (or are not) observed after working memory training: enhanced working memory capacity, enabling people to hold more items in working memory than before training, or enhanced efficiency using the working memory capacity available (e.g., using chunking strategies to remember more items correctly). We then highlight multiple factors that could influence these mechanisms of transfer and thus the success of training interventions. These factors include (1) the nature of the training regime (i.e., intensity, duration, and adaptivity of the training tasks) and, with it, the magnitude of improvements during training, and (2) individual differences in age, cognitive abilities, biological factors, and motivational and personality factors. Finally, we summarize the findings revealed by existing training studies for each of these factors, and thereby present a roadmap for accumulating further empirical evidence regarding the efficacy of working memory training in a systematic way.

Effects of a cognitive training on spatial learning and associated functional brain activations

Background

Both cognitive and physical exercise have been discussed as promising interventions for healthy cognitive aging. The present study assessed the effects of cognitive training (spatial vs. perceptual training) and physical training (endurance training vs. non-endurance training) on spatial learning and associated brain activation in 33 adults (40–55 years). Spatial learning was assessed with a virtual maze task, and at the same time neural correlates were measured with functional magnetic resonance imaging (fMRI).

Results

Only the spatial training improved performance in the maze task. These behavioral gains were accompanied by a decrease in frontal and temporal lobe activity. At posttest, participants of the spatial training group showed lower activity than participants of the perceptual training group in a network of brain regions associated with spatial learning, including the hippocampus and parahippocampal gyrus. No significant differences were observed between the two physical intervention groups.

Conclusions

Functional changes in neural systems associated with spatial navigation can be induced by cognitive interventions and seem to be stronger than effects of physical exercise in middle-aged adults.

Cognitive training and selective attention in the aging brain: an electrophysiological study

OBJECTIVE

Age-related deficits in selective attention are hypothesized to result from decrements in inhibition of task-irrelevant information. Speed of processing (SOP) training is an adaptive cognitive intervention designed to enhance processing speed for attention tasks. The effectiveness of SOP training to improve cognitive and everyday functional performance is well documented. However, underlying mechanisms of these training benefits are unknown.

METHODS

Participants completed a visual search task evaluated using event-related potentials (ERPs) before and after 10 weeks of SOP training or no contact. N2pc and P3b components were evaluated to determine SOP training effects on attentional resource allocation and capacity.

RESULTS

Selective attention to a target was enhanced after SOP training compared to no training. N2pc and P3b amplitudes increased after training, reflecting attentional allocation and capacity enhancement, consistent with previous studies demonstrating behavioral improvements in selective attention following SOP training.

CONCLUSIONS

Changes in ERPs related to attention allocation and capacity following SOP training support the idea that training leads to cognitive enhancement. Specifically, we provide electrophysiological evidence that SOP training may be successful in counteracting age-related declines in selective attention.

SIGNIFICANCE

This study provides important evidence of the underlying mechanisms by which SOP training improves cognitive function in older adults.

Beneficial effects of physical exercise on neuroplasticity and cognition

The human brain adapts to changing demands by altering its functional and structural properties ("neuroplasticity") which results in learning and acquiring skills. Convergent evidence from both human and animal studies suggests that physical activity facilitates neuroplasticity of certain brain structures and as a result cognitive functions. Animal studies have identified an enhancement of neurogenesis, synaptogenesis, angiogenesis and the release of neurotrophins as neural mechanisms mediating beneficial cognitive effects of physical exercise. This review summarizes behavioral consequences and neural correlates at the system level following physical exercise interventions in humans of different ages. The results suggest that physical exercise may trigger processes facilitating neuroplasticity and, thereby, enhances an individual's capacity to respond to new demands with behavioral adaptations. Indeed, some recent studies have suggested that combining physical and cognitive training might result in a mutual enhancement of both interventions. Moreover, new data suggest that to maintain the neuro-cognitive benefits induced by physical exercise, an increase in the cardiovascular fitness level must be maintained.

Preventing cognitive decline in older African Americans with mild cognitive impairment: design and methods of a randomized clinical trial

Mild Cognitive Impairment (MCI) affects 25% of older African Americans and predicts progression to Alzheimer's disease. An extensive epidemiologic literature suggests that cognitive, physical, and/or social activities may prevent cognitive decline. We describe the methods of a randomized clinical trial to test the efficacy of Behavior Activation to prevent cognitive decline in older African Americans with the amnestic multiple domain subtype of MCI. Community Health Workers deliver 6 initial in-home treatment sessions over 2-3 months and then 6 subsequent in-home booster sessions using language, materials, and concepts that are culturally relevant to older African Americans during this 24 month clinical trial. We are randomizing 200 subjects who are recruited from churches, senior centers, and medical clinics to Behavior Activation or Supportive Therapy, which controls for attention. The primary outcome is episodic memory as measured by the Hopkins Verbal Learning Test-Revised at baseline and at months 3, 12, 18, and 24. The secondary outcomes are general and domain-specific neuropsychological function, activities of daily living, depression, and quality-of-life. The negative results of recent clinical trials of drug treatments for MCI and Alzheimer's disease suggest that behavioral interventions may provide an alternative treatment approach to preserve cognition in an aging society.

Long-term concentrative meditation and cognitive performance among older adults

BACKGROUND

The general consensus that cognitive abilities decline with advancing age is supported by several studies that have reported that older adults perform more poorly on multiple tests of cognitive performance as compared to younger adults. To date, preventive measures against this cognitive decline have been mainly focused on dietary, physical, and lifestyle behaviors which could allow older adults to maintain their cognitive abilities into late life. However, much less stress has been laid on evaluating meditation as a preventive measure in such cases in spite of the fact that the role of meditation on attention has been proved in several studies. In the current study, we extend this preliminary idea, examining the practice of concentrative meditation and the differences in the cognitive performance of older adults who have or have not employed this practice long term.

METHODOLOGY

This was a cross-sectional study comparing the cognitive performance of meditators and non-meditators in the geriatric age group. Twenty (age > 55 years) long-term practitioners of Vihangam Yoga meditation (>10 years of practice) were recruited in the present study and were applied six paper-pencil neuropsychological tests for assessment of short-term memory, perceptual speed, attention, and executive functioning. The tests used were: (1) the Digit Span test, (2) the Stroop Color Word test, (3) the Trailmaking test, (4) the Letter Cancellation Task, (5) the digit symbol substitution test, and (6) the Rule Shift Card Test. All the tests were also applied to 20 age- and education-matched geriatric adults who have not practiced the meditation technique.

RESULTS

Vihangam Yogis showed significantly better performances in all these tests of attention (p < .05) except for the digit backward test, where a trend (p = .08) was found in favor of meditators.

CONCLUSION

Long-term Vihangam Yoga meditators have superior cognitive abilities than non-meditators in the old age group. This technique should be studied further for its ability to prevent age-related cognitive decline.

A brief questionnaire on metacognition: psychometric properties

OBJECTIVES

Existing questionnaires on personal views of one's own cognitive functioning are either unduly long, restrict their focus on memory, and/or capture complaints rather than the general status quo. A brief 9-item questionnaire was developed, assessing metacognition with two subscales covering metamemory and metaconcentration.

METHODS

The questionnaire was tested in a sample of healthy women (n = 228) aged 70-93 years, during two face-to-face interviews with an interval of 6 months.

RESULTS

Subscales were confirmed to have factorial validity. While objective cognitive test performance did not predict self-reported everyday functioning, metamemory and metaconcentration accounted for a substantial amount of its variance. The newly developed instrument was shown to be predominantly characterized by latent trait variance components.

CONCLUSION

The presented questionnaire is advantageous for the assessment of metacognition as it is brief and easily applicable. Since metacognition is highly relevant for sustained independence in old age, the questionnaire is suitable to capture important determining factors in research on aging phenomena and processes.

Practice-oriented retest learning as the basic form of cognitive plasticity of the aging brain

It has been well documented that aging is associated with declines in a variety of cognitive functions. A growing body of research shows that the age-related cognitive declines are reversible through cognitive training programs, suggesting maintained cognitive plasticity of the aging brain. Retest learning represents a basic form of cognitive plasticity. It has been consistently demonstrated for adults in young-old and old-old ages. Accumulated research indicates that retest learning is effective, robust, endurable and could occur at a more conceptual level beyond item-specific memorization. Recent studies also demonstrate promisingly broader transfer effects from retest practice of activities involving complex executive functioning to other untrained tasks. The results shed light on the development of self-guided mental exercise programs to improve cognitive performance and efficiency of the aging brain. The relevant studies were reviewed, and the findings were discussed in light of their limitations, implications, and future directions.

Is there a memory profit after repeated learning of subject-performed actions? Comparing direct and long-term memory performance level as a function of age

The present two studies investigated the possibility for improvement and maintenance of episodic memory in young and older adults. In a first study, the performance-enhancing effect of two separate as well as combined learning devices, enactive encoding and repeated learning, was tested. With a time lag of one week, four different series of 30 action phrases were encoded either verbally or by enacting them symbolically. Memory was assessed in four immediate free recall tests. In a second study, the maintenance of the memory profit was tested in an unexpected fifth session half a year later. As expected, there was a steady improvement of memory performance as a function of repeated learning in study one. This holds true regardless of age. In addition, enactive encoding led to a better memory performance than verbal encoding in both age groups. Moreover, younger adults outperformed the elderly regardless of type of encoding. The combination of the two learning devices was not efficient enough to eliminate aging effects in episodic memory. However, memory flexibility is demonstrated also in the elderly. In the long-term follow-up, maintenance of learning and memory could be found in all participant groups.

Factor structure of cognitive ability measures in older African Americans

This study examined the fluid-crystallized distinction of cognitive abilities in African Americans. We analyzed the factorial invariance of a battery of cognitive ability measures in a sample of 197 community-dwelling African American elders. Specifically, factorial invariance was tested in groups of African American elders differing in age (50-61 years, 62-79 years) and education (low, high). Using a partial invariance approach, if non-invariance was found between two groups, we explored the specific model parameters that contributed to the overall lack of invariance. The results indicated that the factor structure was confirmed in the sample as a whole. Evidence of strict invariance was found between age groups. However, a lack of invariance of specific factor loadings, intercepts, and uniqueness terms was found between education groups. The importance of highlighting idiosyncrasies in cognitive performance among African Americans is shown using a within group variation approach.

Cognitive Enrichment in Old Age

Lifestyles with high levels of cognitive activity have been linked to weaker declines in cognitive abilities with aging. Hence, computer-based cognitive training programs that facilitate intense, daily, cognitive practice may help older adults to maintain and improve their cognitive functioning. We present the rationale for and implementation of an internet-based training environment that includes tasks of perceptual speed, episodic memory, and working memory. It was implemented as platform-independent internet-based testing software and used in the COGITO study to investigate intraindividual variability and plasticity in 101 younger (age 20–31) and 103 older (age 65–80) adults across an average of 100 daily practice sessions. Observations from this study and retrospective self-report evaluations demonstrate the program’s feasibility and acceptance among participants.

Visual search for real world targets under conditions of high target-background similarity: Exploring training and transfer in younger and older adults

Real world visual search tasks often require observers to locate a target that blends in with its surrounding environment. However, studies of the effect of target-background similarity on search processes have been relatively rare and have ignored potential age-related differences. We trained younger and older adults to search displays comprised of real world objects on either homogenous backgrounds or backgrounds that camouflaged the target. Training was followed by a transfer session in which participants searched for novel camouflaged objects. Although older adults were slower to locate the target compared to younger adults, all participants improved substantially with training. Surprisingly, camouflage-trained younger and older adults showed no performance decrements when transferred to novel camouflage displays, suggesting that observers learned age-invariant, generalizable skills relevant for searching under conditions of high target-background similarity. Camouflage training benefits at transfer for older adults appeared to be related to improvements in attentional guidance and target recognition rather than a more efficient search strategy.

Mood, Anxiety, and Serum IGF-1 in Elderly Men Given 24 Weeks of High Resistance Exercise

As aging advances, changes in mood and anxiety may imply greater risk of mood disorders, particularly anxiety and depression. Resistance exercise reduces anxiety and lessens risk of depression in the elderly, but little is known of the mechanisms involved. It was hypothesized that the human growth factor (IGF-1) may improve mood and anxiety in elderly participants given resistance training. 43 elderly men ages 65 to 75 years were randomly assigned to two groups, Control ( n = 23) and high resistance Exercise ( n = 20). After 24 wk., the Exercise group showed improved muscular strength and higher IGF-1 serum levels than the Control group, as indicated by mean scores on a visual analogue mood scale and the State-Trait Anxiety Inventory. Intensive resistance training was efficacious in improving mood, anxiety, and IGF-1 serum concentration in elderly individuals free of clinical mood disorders.

Age-related differences in the involvement of the prefrontal cortex in attentional control

We investigated the relative involvement of cortical regions supporting attentional control in older and younger adults during performance on a modified version of the Stroop task. Participants were exposed to two different types of incongruent trials. One of these, an incongruent-ineligible condition, produces conflict at the non-response level, while the second, an incongruent-eligible condition, produces conflict at both non-response and response levels of information processing. Greater attentional control is needed to perform the incongruent-eligible condition compared to other conditions. We examined the cortical recruitment associated with this task in an event-related functional magnetic resonance imaging paradigm in 25 older and 25 younger adults. Our results indicated that while younger adults demonstrated an increase in the activation of cortical regions responsible for maintaining attentional control in response to increased levels of conflict, such sensitivity and flexibility of the cortical regions to increased attentional control demands was absent in older adults. These results suggest a limitation in older adults' capabilities for flexibly recruiting the attentional network in response to increasing attentional demands.

Transfer of computer-based training to simulated driving in older adults

As the population of many industrialized countries ages, the number of older drivers on the roads increases. Statistics show that older drivers are at increased risk for involvement in fatal accidents. One explanation for this is the cognitive and motor declines associated with the aging process. As we age, performance on attention, memory and motor control tasks, three important components of driving, declines. In the present study we examined the relationship between performance on component cognitive tasks and the influence of training on these tasks on the simulated driving performance of older adults. More specifically, we assessed performance on and trained older adults on single and dual tasks of attention, working memory and manual control. Regression analyses demonstrated that performance on the single and dual cognitive tasks and improvements in these computer-based tasks with training were predictive of improvements in driving simulator performance across the course of the study. These data suggest that relatively simple single and dual computer-based tasks and modest amounts of training on these tasks can improve driving performance in older adults, thereby extending functional independence.

The longitudinal impact of cognitive speed of processing training on driving mobility

PURPOSE

To examine how cognitive speed of processing training affects driving mobility across a 3-year period among older drivers.

DESIGN AND METHODS

Older drivers with poor Useful Field of View (UFOV) test performance (indicating greater risk for subsequent at-fault crashes and mobility declines) were randomly assigned to either a speed of processing training or a social and computer contact control group. Driving mobility of these 2 groups was compared with a group of older adults who did not score poorly on the UFOV test (reference group) across a 3-year period.

RESULTS

Older drivers with poor UFOV test scores who did not receive training experienced greater mobility declines as evidenced by decreased driving exposure and space and increased driving difficulty at 3 years. Those at risk for mobility decline who received training did not differ across the 3-year period from older adults in the reference group with regard to driving exposure, space, and most aspects of driving difficulty.

IMPLICATIONS

Cognitive speed of processing training can not only improve cognitive performance but also protect against mobility declines among older drivers. Scientifically proven cognitive training regimens have the potential to enhance the everyday lives of older adults.

Working memory and postural control: adult age differences in potential for improvement, task priority, and dual tasking

We investigate dynamic posture control and working memory (NBack) retest practice in young and older adults, focusing on older adults' potential for improvement in the component tasks but more importantly in dual-task performance. Participants performed the 2 tasks in 11 sessions under single- and dual-task conditions. Posture improvement was observed with retest practice for both groups. Increase in cognitive load after initial practice led to greater dual-task costs in both tasks in older adults and higher costs in memory in young adults. With continued practice, costs were reduced by both groups; however, the 2 groups focused improvement on different tasks: Older adults focused on posture but young adults on cognition. These results emphasize older adults' potential for improvement in dual-task performance and their flexibility to utilize the practice gains in posture to optimize cognitive performance.

Contribution of education, occupation and cognitively stimulating activities to the formation of cognitive reserve

The cognitive reserve (CR) concept posits that there is individual variability in processing task demands and coping with neurodegenerative diseases. This variability can be attributed to the protective effects derived from continuous cognitive stimulation throughout life, including formal education, engagement in cognitively stimulating activities and occupation. These can result in protection against age-related cognitive decline and reduce the risk of developing Alzheimer’s disease. The aim of this review is to summarize the main features of CR formation and to discuss the challenges in carrying out CR research in developing countries.

Age-related differences in auditory evoked responses during rapid perceptual learning

OBJECTIVE

Young and older adults can learn to rapidly discriminate between elementary visual and auditory features. While growing evidence supports the notion that such behavioral improvement is paralleled by neuroplastic changes in corresponding sensory areas during adulthood, studies have not examined practice-related improvement in older adults and the corresponding changes in neural activity.

METHODS

We used event-related potentials (ERPs) to investigate the effects of age on rapid learning-related changes in listeners' ability to identify two phonetically different vowels presented simultaneously.

RESULTS

During the first hour of testing, young and older listeners showed comparable behavioral improvement in identifying both vowels. In young adults, learning was paralleled by enhanced amplitudes of early (130 ms) and late (320 ms) ERP waves over the right temporal lobe, as well as an increased negative wave over the midline parietal region, peaking at about 400 ms after sound onset. The practice-related changes over the right temporal lobe were not present in older adults whereas the learning effect observed over the parietal region was present in both young and older adults. In older adults, behavioral improvement was also associated with reduced N1 amplitude recorded at inferior and posterior temporal/occipital scalp sites while no such changes were observed in young adults.

CONCLUSIONS

Age-related differences in neural activity during learning suggest that neural networks supporting behavioral improvements in speech segregation and identification change during the course of aging.

SIGNIFICANCE

This research highlights the role of practice on concurrent sound perception and may facilitate the development of training programs that may help older listeners to parse the auditory scene into component sound sources.

The impact of resistance exercise on the cognitive function of the elderly

PURPOSE

The purpose of this study was to assess the impact of 24 wk of resistance training at two different intensities on cognitive functions in the elderly.

METHODS

Sixty-two elderly individuals were randomly assigned to three groups: CONTROL (N = 23), experimental moderate (EMODERATE; N = 19), and experimental high (EHIGH; N = 20). The volunteers were assessed on physical, hemodynamic, cognitive, and mood parameters before and after the program.

RESULTS

On the 1 RM test (P < 0.001), the two experimental groups performed better than the CONTROL group, but they did not show differences between themselves. The EHIGH group gained more lean mass (P = 0.05) than the CONTROL group and performed better on the following tests: digit span forward (P < 0.001), Corsi's block-tapping task backward (P = 0.001), similarities (P = 0.03), Rey-Osterrieth complex figure immediate recall (P = 0.02), Toulouse-Pieron concentration test errors (P = 0.01), SF-36 (general health) (P = 0.04), POMS (tension-anxiety, P = 0.04; depression-dejection, P = 0.03; and total mood disorder, P = 0.03). The EMODERATE group scored higher means than the CONTROL group on digit span forward (P < 0.001), Corsi's block-tapping task backward (P = 0.01), similarities (P = 0.02), Rey-Osterrieth complex figure immediate recall (P = 0.02), SF-36 (general health, P = 0.005; vitality, P = 0.006), POMS (tension-anxiety, P = 0.001; depression-dejection, P = 0.006; anger-hostility, P = 0.006; fatigue-inertia, P = 0.02; confusion-bewilderment, P = 0.02; and total mood disorder, P = 0.001). We also found that IGF-1 serum levels were higher in the experimental groups (EMODERATE, P = 0.02; EHIGH, P < 0.001).

CONCLUSIONS

Moderate- and high-intensity resistance exercise programs had equally beneficial effects on cognitive functioning.

Protocol for Fit Bodies, Fine Minds: a randomized controlled trial on the affect of exercise and cognitive training on cognitive functioning in older adults

Background

Declines in cognitive functioning are a normal part of aging that can affect daily functioning and quality of life. This study will examine the impact of an exercise training program, and a combined exercise and cognitive training program, on the cognitive and physical functioning of older adults.

Methods/Design

Fit Bodies, Fine Minds is a randomized, controlled trial. Community-dwelling adults, aged between 65 and 75 years, are randomly allocated to one of three groups for 16 weeks. The exercise-only group do three 60-minute exercise sessions per week. The exercise and cognitive training group do two 60-minute exercise sessions and one 60-minute cognitive training session per week. A no-training control group is contacted every 4 weeks. Measures of cognitive functioning, physical fitness and psychological well-being are taken at baseline (0 weeks), post-test (16 weeks) and 6-month follop (40 weeks). Qualitative responses to the program are taken at post-test.

Discussion

With an increasingly aged population, interventions to improve the functioning and quality of life of older adults are particularly important. Exercise training, either alone or in combination with cognitive training, may be an effective means of optimizing cognitive functioning in older adults. This study will add to the growing evidence base on the effectiveness of these interventions.

Trial Registration

Australian Clinical Trials Register: ACTRN012607000151437

Correlates of health literacy in patients with chronic heart failure

PURPOSE

Many older adults have inadequate health-related literacy, which is associated with poor health outcomes. Thus, it is important to identify determinants of health literacy. We investigated relationships between health literacy and general cognitive and sensory abilities, as well as education, health, and demographic variables, in a community sample of middle-aged and older adults.

DESIGN AND METHODS

Participants were 314 community-dwelling adults (67% female, 48% African American) diagnosed with chronic heart failure recruited for a pharmacist-based intervention study to improve adherence to chronic heart failure medications. We adminstered demographic, health, education, cognitive (e.g., processing speed, working memory), and sensory measures, and the Short Test of Functional Health Literacy in Adults (STOFHLA), as part of the baseline condition of this study.

RESULTS

STOFHLA scores were lower for participants who were older, less educated, male, African American, had more comorbidities, or scored lower on all cognitive ability measures. Hierarchical linear regression analyses showed that education and cognitive ability were independently associated with the STOFHLA measure and explained age differences in health literacy.

IMPLICATIONS

The association of cognitive abilities and literacy has important implications for health literacy models and for interventions to reduce the impact of low health literacy on health outcomes. For example, medication instructions should be designed to reduce comprehension demands on general cognitive abilities as well as literacy skills.

Should One Use Medications in Combination With Cognitive Training? If So, Which Ones?

In this article, we review current research regarding diagnosis of cognitive impairment in nondemented adults and discuss why medications and cognitive training together may be more beneficial than either alone. We also review potential cognitive enhancers and future research challenges. There are major reasons for such research: (a) Large numbers of older adults without dementia but with cognitive problems are not treatable with current cognitive training techniques; (b) some medications offer a rationale (i.e., cognitive enhancement) and some evidence that they might be a useful adjunct; and (c) there are unanswered questions about which population to target, which medications to use, how to administer them, and issues regarding tolerance and use of appropriate (active) placebo controls. As the number of cognitively impaired older adults grows, it is likely that there will be pressure to treat more broadly with both medications and cognitive training.

The Impact of Speed of Processing Training on Cognitive and Everyday Functions

We combined data from six studies, all using the same speed of processing training program, to examine the mechanisms of training gain and the impact of training on cognitive and everyday abilities of older adults. Results indicated that training produces immediate improvements across all subtests of the Useful Field of View test, particularly for older adults with initial speed of processing deficits. Age and education had little to no impact on training gain. Participants maintained benefits of training for at least 2 years, which translated to improvements in everyday abilities, including efficient performance of instrumental activities of daily living and safer driving performance.

An Engagement Model of Cognitive Optimization Through Adulthood

The engagement hypothesis suggests that social and intellectual engagement may buffer age-related declines in intellectual functioning. At the same time, some have argued that social structures that afford opportunities for intellectual engagement throughout the life span have lagged behind the demographic shift toward an expanding older population. Against this backdrop, we developed the Senior Odyssey, an existing team-based program of creative problem solving. We tested the engagement hypothesis in a field experiment. Relative to controls, Senior Odyssey participants showed improved speed of processing, marginally improved divergent thinking, and higher levels of mindfulness and need for cognition after the program. This pilot translational project suggests that the Senior Odyssey program may serve as one effective model of engagement with good scaling-up potential.