Executive functioning as a mediator of the relationship between age and episodic memory in healthy aging

Beta-band MEG signal power changes in older adults after physical exercise program with and without additional cognitive training

Physical exercise has been considered to be an efficient mean of preserving cognitive function and it influences both the structural and functional characteristics of the brain. It has especially been shown to increase brain plasticity, the capacity to re-structure brain properties in response to interaction, such as cognitive practice. Studies have also examined the potential additive effect of cognitive training on the documented benefit of physical exercise, commonly, however, not at the neural level. We monitored, using magnetoencephalography (MEG), the brain processes associated with executive functions in older individuals who participated in a 12-month randomized controlled trial including two research arms: physical and cognitive training vs physical training alone. Measurements were conducted at 0 months, 6 months, and 12 months. The addition of cognitive training was associated with better performance in the Stroop test that reflects executive control. The extra benefit of cognitive training was also manifested as decreased modulation of beta frequency band (15-25 Hz) especially to difficult distractors. As beta band activity is associated with attentional control, this indicates fewer resources needed to inhibit irrelevant sensory inputs. These results imply an enhancing role of cognitive elements integrated with physical training in improving or maintaining executive functions in older individuals.

Executive functioning predicts discrepancies between objective and self-reported physical activity in older adults: a pilot study

Physical activity (PA) has been linked to cognitive functioning and mental health in older adulthood. Multiple subjective (i.e., self-report) and objective measures (e.g., pedometer) have been used to assess PA, however their agreement varies across studies. This pilot study examined cognitive predictors of the agreement between subjective and objectively measured PA. A total of 30 community-dwelling older adults completed a neuropsychological battery, as well as a measure of subjective PA and wore a wristwatch-based pedometer for 30 days to assess objective PA. Greater discrepancy between subjective and objective PA was correlated with poorer executive functioning (r = -.44, p = .02), and this remained true in regression models after controlling for age and education (b = .-54, p = .01). Older adults with lower executive functioning may be more likely to inaccurately report time spent engaging in PA. Future studies should explore whether this relationship holds in larger samples.

Comparison of Traditional and Virtual Reality-Based Episodic Memory Performance in Clinical and Non-Clinical Cohorts

The California Verbal Learning Test, Second Edition (CVLT-II) and the Virtual Environment Grocery Store (VEGS) use list learning and recognition tasks to assess episodic memory. This study aims to: (1) Replicate prior construct validity results among a new sample of young adults and healthy older adults; (2) Extend this work to a clinical sample of older adults with a neurocognitive diagnosis; (3) Compare CVLT-II and VEGS performance among these groups; and (4) Validate the independence of CVLT and VEGS episodic memory performance measures from executive functioning performance measures. Typically developing young adults (n = 53) and older adults (n = 85), as well as older adults with a neurocognitive diagnosis (n = 18), were administered the CVLT-II, VEGS, and D-KEFS CWIT. Results found that (1) the relationship of the VEGS and CVLT-II measures was highly correlated on all variables, (2) compared to the CVLT-II, participants (particularly older adults) recalled fewer items on the VEGS, and (3) the CVLT-II and VEGS were generally independent of D-KEFS CWIT. It appeared that the VEGS may be more difficult than the CVLT-II, possibly reflecting the word length effect. Performance may have also been impacted by the presence of everyday distractors in the virtual environment.

The roles of executive functioning, simple attention, and medial temporal lobes in early learning, late learning, and delayed recall

Fractionating performance of a verbal list-learning test can provide a nuanced interpretation of the relationship between brain networks and learning and memory abilities. Within older adult samples, including those with mild cognitive impairment and Alzheimer’s disease, cortical volumes for attention and executive functioning networks correlate more strongly with neuropsychological performance measures of early learning trials relative to late learning and delayed recall. In contrast, medial temporal lobe (MTL) structures, such as the hippocampus, are more strongly correlated to performance on late learning and delayed recall measures relative to early learning. We sought to extend these findings by evaluating the contributions of simple attention, executive function (EF), and MTL structures to learning and recall in a cognitively heterogeneous sample of older adults that included healthy controls (n = 54), adults with MCI (n = 63), and those with dementia (n = 13). We used canonical correlation analyses to test the hypotheses that the contributions of EF, simple attention, and the MTL to verbal memory would differ across phases of learning and recall. Results showed that relationships between the MTL and memory were the only ones to demonstrate a graded pattern of association, ranging from r = .46 to .57 across early learning, late learning, and delayed recall. Simple attention and EF were both significantly and moderately related to learning and recall, but those relationships did not vary across phases as hypothesized. We explore alternative interpretations for our discrepant findings, including the influence of sample characteristics and methodology, advocating for multivariate approaches.

Episodic memory and aging: Benefits of physical activity depend on the executive resources required for the task

Physical activity has beneficial effects on executive functions and episodic memory, two processes affected by aging. These benefits seem to depend on the type of memory task, but only a few studies have evaluated them despite their importance in understanding aging. This study aimed to confirm that the benefits of physical activity on episodic memory in older adults vary according to the executive resources required by the memory task, comparing free recall and cued recall. Thirty-seven young adults and 37 older adults performed two memory tasks and an updating task. The two groups had a similar level of physical activity over the preceding 12 months, assessed by a questionnaire. Both the memory and the updating tasks were performed better by the younger than the older adults. A similar cueing effect was observed in the two groups. Physical activity was positively correlated with updating and free recall, but not with cued-recall, and only in older adults. Regression analyses indicated that physical activity accounted for 24% of the variance in free recall in older adults. Updating did not predict free recall (ns) when physical activity was entered in the analysis. The present results show that the benefits of physical activity vary with age and episodic memory task. Only free-recall performance, which relies on updating, seems to depend on physical activity, suggesting that the executive resources required for the task play an important role in the effect of physical activity on memory performance. This should be investigated in greater depth in subsequent studies.

Reliability and Validity of a Home-Based Self-Administered Computerized Test of Learning and Memory Using Speech Recognition

INTRODUCTION

The objective of this study is to evaluate the reliability and validity of the ReVeRe^TM word list recall test (RWLRT), which uses speech recognition, when administered remotely and unsupervised.

METHODS

Prospective cohort study. Participants included 249 cognitively intact community dwelling older adults. Measures included clinician administered neuropsychological assessments at baseline and unsupervised remotely administered tests of cognition from six time-points over six months.

RESULTS

The RWLRT showed acceptable validity. Reliability coefficients varied across time points, with poor reliability between times 1 and 2 and fair-to-good reliability across the remaining five testing sessions. Practice effects were observed with repeated administration as expected.

DISCUSSION

Unsupervised computerized tests of cognition, particularly word list learning and memory tests that use speech recognition, have significant potential for large scale early detection and long-term tracking of cognitive decline due to AD.

The Effectiveness of Item-Specific Encoding and Conservative Responding to Reduce False Memories in Patients with Mild Cognitive Impairment and Mild Alzheimer's Disease Dementia

OBJECTIVE

Patients with mild Alzheimer's disease dementia are more susceptible to false memories than healthy older adults. Evidence that these patients can use cognitive strategies to reduce false memory is inconsistent.

METHOD

In the present study, we examined the effectiveness of conservative responding and item-specific deep encoding strategies, alone and in combination, to reduce false memory in a categorized word list paradigm among participants with mild Alzheimer's disease dementia (AD), amnestic single-domain mild cognitive impairment (MCI), and healthy age-matched older controls (OCs). A battery of clinical neuropsychological measures was also administered.

RESULTS

Although use of conservative responding alone tended to reduce performance in the MCI and OC groups, both deep encoding alone and deep encoding combined with conservative strategies led to improved discrimination for both gist memory and item-specific recollection for these two groups. In the AD group, only gist memory benefited from the use of strategies, boosted equally by deep encoding alone and deep encoding combined with conservative strategies; item-specific recollection was not improved. No correlation between the use of these strategies and performance on neuropsychological measures was found.

CONCLUSIONS

These results suggest that further evaluation of these strategies is warranted as they have the potential to reduce related and unrelated memory errors and increase both gist memory and item-specific recollection in healthy older adults and individuals with amnestic MCI. Patients with AD were less able to benefit from such strategies, yet were still able to use them to reduce unrelated memory errors and increase gist memory.

L’anxiété chez le jeune adulte et chez le sujet âgé pendant le confinement lié à la pandémie du SARS-CoV2

Chez le sujet âgé, certains troubles tels que la dépression sont difficiles à diagnostiquer et ont un aspect différent de la pathologie qui survient chez le jeune adulte. Nous nous sommes consacrés dans cette étude à évaluer le niveau de l’anxiété à travers la somatisation chez les participants afin de mettre en évidence la différence entre l’anxiété chez le jeune adulte et l’anxiété chez le sujet âgé. Cette étude est une suite à la publication concernant une nouvelle échelle de somatisation. Les analyses statistiques ont été faites sur la même population. Ce travail a été réalisé à l’aide de l’échelle de somatisation sur un échantillon de 235 participants ayant plus de 18 ans. Ces participants étaient des hommes et femmes qui ont été confinés au Maroc lors de la pandémie du SARS-CoV2. Nous avons constaté que les jeunes adultes présentaient une anxiété plus intense que les sujets âgés au cours de cette période de confinement et que les sujets âgés étaient plus nombreux à ressentir de l’anxiété dite « normale » suite à la pandémie du COVID-19.

Comparison of Traditional Chinese Exercises and Nontraditional Chinese Exercise Modalities on Cognitive and Executive Function in Community Middle-Aged and Older Adults: A Cross-Sectional Study

Background

Current evidence indicates that regular exercise can have a positive impact on cognitive function in older adults, but whether different exercise modalities may induce differential protective effects in different cognitive domains is uncertain.

Objective

To compare the effect of traditional Chinese exercise (TCE) modalities and non-traditional Chinese exercise (non-TCE) modalities on cognitive and executive function in community middle-aged and older adults through a cross-sectional study.

Methods

A total of 350 community middle-aged and older adults aged over 55 years participated in this study. Information on demographic characteristics, lifestyle and behavioural habits, and regular exercise was collected by a self-designed questionnaire. Global cognitive ability and executive function were assessed using the Montreal Cognitive Assessment (MoCA) scale, the clock drawing test (CDT), the animal naming test (ANT), and the trail making test (TMT). Eligible subjects were categorized into the no regular exercise (no-RE), non-TCE, or TCE groups according to their self-reported exercise information. Comparisons of global cognitive and executive function among the three groups were conducted using ANOVA or the general linear model with adjustment for potential confounding factors.

Results

The results showed that for the non-TCE or TCE groups, the MoCA and CDT scores were significantly higher, and the TMT-A test time was significantly shorter than those in the no-RE group (all P < 0.05), but no significant difference was observed for the TMT-B and ANT tests. After adjustment for potential confounding factors, the MoCA, the CDT, and TMT-A scores in the TCE group were significant compared to those in the no-RE group. In addition, subgroup analysis showed that in the TCE group, the MoCA scores were significantly higher than those in the non-TCE group. Furthermore, in the TCE group, the CDT scores for those with an exercise duration of <5 years were higher and the TMT-A test time for those with an exercise duration of ≥5 years was shorter than those in the non-TCE group.

Conclusions

Both TCE and non-TCE have potential protective effects on global cognitive and executive function in community middle-aged and older adults. Compared to the non-TCE modality, the TCE modality may have a more positive association with these protective effects. Furthermore, prospective studies are needed to confirm these findings.

Stressful Life Events and Racial Disparities in Cognition Among Middle-Aged and Older Adults

BACKGROUND

It is well-documented that African Americans have elevated risk for cognitive impairment and dementia in late life, but reasons for the racial disparities remain unknown. Stress processes have been linked to premature age-related morbidity, including Alzheimer's and related dementias (ADRD), and plausibly contribute to social disparities in cognitive aging.

OBJECTIVE

We examined the relationship between stressful life events and cognitive decline among African American and White participants enrolled in the Wisconsin Registry for Alzheimer's Prevention (WRAP).

METHODS

Linear mixed models including demographic, literacy, and health-related covariates were used to estimate (1) relationships between a life event index score and decline in cognitive test performance in two domains of executive function (Speed & Flexibility, Working Memory) and one domain of episodic memory (Verbal Learning & Memory) among 1,241 WRAP enrollees, stratified by race, and (2) contributions of stressful life events to racial differences in cognition within the full sample.

RESULTS

African Americans (N = 50) reported more stressful life events than Whites (N = 1,191). Higher stress scores associated with poorer Speed & Flexibility performance in both groups, though not with declines across time, and partially explained racial differentials in this domain. Among African Americans only, stressor exposure also associated with age-related decline in Verbal Learning & Memory. Stressor-cognition relationships were independent of literacy and health-related variables.

CONCLUSIONS

Greater lifetime stress predicted poorer later-life cognition, and, in a small sample of African Americans, faster declines in a key domain of episodic memory. These preliminary findings suggest that future work in large minority aging cohorts should explore stress as an important source of modifiable, socially-rooted risk for impairment and ADRD in African Americans, who are disproportionately exposed to adverse experiences across the life course.

Cognitive control beliefs and cognitive functioning in mid- to late-life

OBJECTIVES

Older adults experience age-related cognitive declines and often feel as if the severity of these declines is out of their control. Recent research suggests, though, that control beliefs may be related to less age-related declines. The aim of the current study was to investigate cognitive domain-specific control beliefs and the link between those cognitive control beliefs and cognitive functioning among a nationwide sample of adults (N = 3,670), as well as to explore whether cognitive control beliefs moderated the relationship between age and cognitive functioning.

METHOD

The aims were addressed using data from the national Midlife in the United States study (MIDUS II). Cognitive functioning was assessed using the Brief Test of Adult Cognition by Telephone (BTACT), and cognitive control beliefs were assessed with the Personality in Intellectual Aging Contexts (PIC) Inventory Control Scales.

RESULTS

Regression analyses revealed that adults with higher control beliefs demonstrated better cognitive functioning. Moderation analyses indicated cognitive control beliefs moderated the relationship between age and executive functioning, but not the association between age and episodic memory.

CONCLUSION

Results suggested that the relationship between age and executive functioning was weaker at high levels of cognitive control beliefs. Future research should establish the directionality of the effect between cognitive control beliefs and cognition and investigate the association between control beliefs and cognition in samples at higher risk for substantial cognitive decline, including the oldest-old.

Differences in Semantic Memory Encoding Strategies in Young, Healthy Old and MCI Patients

Associative processes, such as the encoding of associations between words in a list, can enhance episodic memory performance and are thought to deteriorate with age. Here, we examine the nature of age-related deficits in the encoding of associations, by using a free recall paradigm with visual arrays of objects. Fifty-five participants (26 young students; 20 cognitive healthy older adults; nine patients with Mild Cognitive Impairment, MCI) were shown multiple slides (experimental trials), each containing an array of nine common objects for recall. Most of the arrays contained three objects from three semantic categories, each. In the remaining arrays, the nine objects were unrelated. Eye fixations were also monitored during the viewing of the arrays, in a subset of the participants. While for young participants the immediate recall was higher for the semantically related arrays, this effect was diminished in healthy elderly and totally absent in MCI patients. Furthermore, only in the young group did the sequence of eye fixations show a semantic scanning pattern during encoding, even when the related objects were non- adjacent in the array. Healthy elderly and MCI patients were not influenced by the semantic relatedness of items during the array encoding, to the same extent as young subjects, as observed by a lack of (or reduced) semantic scanning. The results support a version of the encoding of the association aging-deficit hypothesis.

Incidental Learning: A Systematic Review of Its Effect on Episodic Memory Performance in Older Age

Episodic memory is the capacity to encode, store, and retrieve information of specific past events. Several studies have shown that the decline in episodic memory accompanies aging, but most of these studies assessed memory performance through intentional learning. In this approach, the individuals deliberately acquire knowledge. Yet, another method to evaluate episodic memory performance-receiving less attention by the research community-is incidental learning. Here, participants do not explicitly intent to learn. Incidental learning becomes increasingly important over the lifespan, since people spend less time in institutions where intentional learning is required (e.g., school, university, or at work). Yet, we know little how incidental learning impacts episodic memory performance in advanced age. Likewise, the neural mechanisms underlying incidental learning in older age remain largely unknown. Thus, the immediate goal of this review was to summarize the existing literature on how incidental learning changes with age and how neural mechanisms map onto these age-related changes. We considered behavioral as well as neuroimaging studies using incidental learning paradigms (alone or in combination with intentional learning) to assess episodic memory performance in elderly adults. We conducted a systematic literature search on the Medline/PubMed, Cochrane, and OVID SP databases and searched the reference lists of articles. The search yielded 245 studies, of which 34 concerned incidental learning and episodic memory in older adults. In sum, these studies suggest that aging particularly affects episodic memory after incidental learning for cognitively demanding tasks. Monitoring deficits in older adults might account for these findings since cognitively demanding tasks need increased attentional resources. On a neuronal level, dysregulation of the default-mode-network mirrors monitoring deficits, with an attempt to compensate through increased frontal activity. Future (neuroimaging) studies should systematically evaluate retrieval tasks with diverging cognitive load and consider the influence of attention and executive functions in more detail.

Increased flanker task and forward digit span performance in caudate-nucleus-dependent response strategies

One of two memory systems can be used to navigate in a new environment. Hippocampus-dependent spatial strategy consists of creating a cognitive map of an environment and caudate nucleus-dependent response strategy consists of memorizing a rigid sequence of turns. Spontaneous use of the response strategy is associated with greater activity and grey matter within the caudate nucleus while the spatial strategy is associated with greater activity and grey matter in the hippocampus. The caudate nucleus is involved in executive functions such as working memory, cognitive control and certain aspects of attention such as attentional disengaging. This study therefore aimed to investigate whether response learners would display better performance on tests of executive and attention functioning compared to spatial learners. Fifty participants completed the 4/8 virtual maze to assess navigational strategy, the forward and backward visual digit span and the Attention Network Test - Revised to assess both attention disengagement and cognitive control. Results revealed that response learners showed significantly higher working memory capacity, more efficient attention disengagement and better cognitive control. Results suggest that response learners, who putatively display more grey matter and activity in the caudate nucleus, are associated with better working memory span, cognitive control and attentional disengagement.

Exploring the contribution of executive functions to on-road driving performance during aging: A latent variable analysis

With the aging of the population the issue of older drivers safety has gained importance in recent years. Age-related cognitive decline is frequently cited as the main cause of unsafe driving performance in older drivers.

OBJECTIVE

The present study investigated how executive functions (EFs), measured as latent variables, are related to on-road driving performance during aging.

METHOD

One hundred and twenty-six participants aged from twenty to eighty-two, completed a two hundred and forty-seven km on-road driving test and a set of executive tasks selected to tap three often postulated EFs: inhibition (inhibiting prepotent responses), updating (updating working memory representations), and shifting (shifting task sets).

RESULTS

Confirmatory factor analysis reproduces previous results obtained by Miyake et al. (2000), Miyake and Friedman (2012) of unity and diversity of EFs in an adult life span sample. Structural equation modeling suggested that on-road driving performance was related to inhibition. Furthermore, findings indicate that the age-related driving performance decline in normal aging may be mediated by the inhibition function.

CONCLUSIONS

The results highlight the importance of a proper method to assess executive functioning in a specific domain as well as emphasising the major role of those functions in driving performance while aging.

The Influence of Fluid Intelligence, Executive Functions and Premorbid Intelligence on Memory in Frontal Patients

Objective: It is commonly thought that memory deficits in frontal patients are a result of impairments in executive functions which impact upon storage and retrieval processes. Yet, few studies have specifically examined the relationship between memory performance and executive functions in frontal patients. Furthermore, the contribution of more general cognitive processes such as fluid intelligence and demographic factors such as age, education, and premorbid intelligence has not been considered. Method: Our study examined the relationship between recall and recognition memory and performance on measures of fluid intelligence, executive functions and premorbid intelligence in 39 frontal patients and 46 healthy controls. Results: Recall memory impairments in frontal patients were strongly correlated with fluid intelligence, executive functions and premorbid intelligence. These factors were all found to be independent predictors of recall performance, with fluid intelligence being the strongest predictor. In contrast, recognition memory impairments were not related to any of these factors. Furthermore, age and education were not significantly correlated with either recall or recognition memory measures. Conclusion: Our findings show that recall memory in frontal patients was related to fluid intelligence, executive functions and premorbid intelligence. In contrast, recognition memory was not. These findings suggest that recall and recognition memory deficits following frontal injury arise from separable cognitive factors. Recognition memory tests may be more useful when assessing memory functions in frontal patients.

Intraindividual Variability in Executive Function Performance in Healthy Adults: Cross-Sectional Analysis of the NAB Executive Functions Module

The current study was aimed at investigating across-tasks intraindividual variability, also termed dispersion, in EF performance. The German adaptation of the Neuropsychological Assessment Battery (NAB) was used as a measure of EFs. Data of 444 participants aged 18-99 from six NAB Executive Functions Module subtests (i.e., Planning, Mazes, Letter Fluency, Judgment, Categories, and Word Generation) along with the NAB Total Index score as a measure of overall cognitive ability were analyzed. Maximum discrepancy (MD) was applied as a measure of dispersion. MD values ranged from 0.47 to 5.20 indicating substantial across-tasks dispersion in EF performance. Furthermore, dispersion moderately decreased with advancing age. Taking overall cognitive ability into account revealed that dispersion might be lower at older ages; especially, when associated with low overall ability levels. The dedifferentiation hypothesis offers a plausible explanation for these findings. That is, the cognitive profiles of older people might be less heterogenous than that of younger people, which may be due to age-related central nervous system constraints.

[Memory processes and executive functioning: novel trends for research]

The existence of processes common to memory systems and executive functioning was evidenced by studies in the domain of cerebral neuroimaging, individual differences (mainly in normal aging) and, to a lesser extent, neuropsychology. Executive functioning depends on a large antero-posterior brain network, some regions of which (the middle dorsolateral and ventrolateral cortex, the dorsal anterior cingulate cortex) are involved in a series of executive processes, but also in encoding and retrieval of information in episodic memory and short-term memory. A consequence of lesions in frontal areas is to impair strategical organization of the information to-be-processed (an executive process) and thus leads to a lower memory capacity in frontal patients. Moreover, executive abilities will influence both memory efficiency and the associated brain networks even in people without brain pathology. These data attest to the importance of the relationships between executive and memory processes for an optimal cognitive functioning. Recent advances in neuroimaging and electrophysiology data acquisition and analysis techniques should allow us to better determine and understand the fashion in which these relationships work.

Neural correlates of successful memory retrieval in aging: Do executive functioning and task difficulty matter?

The current experiment aimed to explore age differences in brain activity associated with successful memory retrieval in older adults with different levels of executive functioning, at different levels of task demand. Memory performance and fMRI activity during a recognition task were compared between a young group and two older groups characterized by a low (old-low group) vs. high (old-high group) level of executive functioning. Participants first encoded pictures, presented once (Hard condition) or twice (Easy condition), and then completed a recognition memory task. Old-low adults had poorer memory performance than the two other groups, which did not differ, in both levels of task demands. In the Easy condition, even though older adults demonstrated reduced activity compared to young adults in several regions, they also showed additional activations in the right superior frontal gyrus and right parietal lobule (positively correlated to memory accuracy) for the old-high group and in the right precuneus (negatively correlated to memory accuracy), right anterior cingulate gyrus and right supramarginal gyrus for the old-low group. In the Hard condition, some regions were also more activated in the young group than in the older groups. Vice versa, old-high participants demonstrated more activity than either the young or the old-low group in the right frontal gyrus, associated with more accurate memory performance, and in the left frontal gyrus. In sum, the present study clearly showed that age differences in the neural correlates of retrieval success were modulated by task difficulty, as suggested by the CRUNCH model, but also by interindividual variability, in particular regarding executive functioning.

A longitudinal study of psychological changes in cognition and self in late life

The diversity and resilience characteristic of the closing phases of human development are investigated by longitudinal study of change and development in about the last 30 years of the life-span. The Australian Longitudinal Study of Ageing (ALSA) is a population-based psychobiosocial and behavioural study of a cohort of 1,947 adults from Adelaide over the age of 70 years. Four annual waves of data collection started in 1992. At Waves 1 and 3, an extensive personal interview covered psychological, behavioural, social, biomedical, economic, and other contextuol variables. Participants also had the opportunity to provide psychological data on cognitive and psychosocial (self) dimensions through completion of a series of objective assessments and standard paper-and-pencil inventories. Data from these two waves is used to describe and explain changes in cognitive and psychosocial domains, particularly the complexity of functioning, potential gains and losses in memory and well-being, and the interplay amongst these aspects of functioning. Once a range of noncognitive and cognitive contextual factors are taken into account, individual differences in processing and intrapersonal resources contribute significantly and substantially to functioning in each domain, and the contribution from ageing per se is minimised. Furthermore, a “limited impact” hypothesis of late life development suggests that later declines may be a byproduct of rather large decrements in some subset of a population, with the majority showing stability. Insofar as heterogeneity increases with ageing, age per se is increasingly less able to predict functioning. This work identifies some key sources of heterogeneity that may be indicative of ageing well.

Cognitive Rehabilitation with Older Adults

The proportion of older adults seeking rehabilitation services are certain to rise as the population ages. Cognitive rehabilitation techniques can be successfully adapted and used with older adults with a range of clinical diagnoses. An understanding of cognitive changes which could be expected as a result of “normal” (non-disease-related) aging is essential for both assessment and treatment planning for this group. Age-related changes in attention, memory and executive functioning are briefly noted. Common cognitive sequelae of head-injury, depression and dementia are discussed, and useful assessment and rehabilitation strategies described. Case illustrations are used to illustrate major points.

Everyday-like memory for objects in ageing and Alzheimer's disease assessed in a visually complex environment: The role of executive functioning and episodic memory

To investigate everyday memory, more and more studies rely on virtual-reality applications to bridge the gap between in situ approaches and laboratory settings. In this vein, the present study was designed to assess everyday-like memory from the virtual reality-based Human Object Memory for Everyday Scenes (HOMES) test (Sauzéon et al., , Exp. Psychol., 59, 99) in ageing and in Alzheimer's disease (AD). Two aims motivated this study: the first was to assess multiple processes of episodic memory (EM) functioning embedded within contexts closely related to real life in ageing and AD using the multi-trial free-recall paradigm, and the second aim was to evaluate the mediating effects of executive functioning (EF), EM, and subjective memory complaints (SMCs) on age differences in the HOMES measures and in AD. To this end, the HOMES test and neurocognitive tests of EF and EM were administered to 23 younger adults, 23 older adults, and 16 patients with AD. The results were: firstly, compared to young adults, elderly adults presented only free-recall decline that almost disappeared in recognition condition whereas AD patients exhibited a poor clustering, learning, and recognition performance, and also a high amount of false recognition; secondly, age differences as well as AD related deficits on the HOMES test were mediated by both memory and EF measure while those observed on false memory indices were only mediated by EM measure; thirdly, the HOMES indices are related to SMCs even when episodic or EF measures are controlled. Overall, the results supported the fact that the VR-based memory test is an appropriate device to capture age-related differences as well as the AD effect with respect to both in situ and laboratory settings.

Everyday-like memory and its cognitive correlates in healthy older adults and in young patients with traumatic brain injury: a pilot study based on virtual reality

PURPOSE STATE: A pilot-study with a comparison approach between aging and traumatic brain injury (TBI) is proposed to investigate everyday object memory patterns using a virtual HOMES test.

METHODS

Sixteen young controls, 15 older adults and 15 TBI patients underwent the HOMES test and traditional tests.

RESULTS

Older adults and TBI patients exhibited similar HOMES performances: poor recall, a greater recognition benefit, high false recognitions, but intact clustering and proactive interference effects. The age-related differences for HOMES measures were mainly mediated by executive functioning, while the HOMES performances in the TBI group were correlated with memory measures.

CONCLUSION

The differential cognitive mediating effects for a similar everyday-like memory pattern are discussed by highlighting the need for more cautious interpretations of cognitive mechanisms behind similar behavioral patterns in different populations especially in clinical and rehabilitation settings.

Event segmentation ability uniquely predicts event memory

Memory for everyday events plays a central role in tasks of daily living, autobiographical memory, and planning. Event memory depends in part on segmenting ongoing activity into meaningful units. This study examined the relationship between event segmentation and memory in a lifespan sample to answer the following question: Is the ability to segment activity into meaningful events a unique predictor of subsequent memory, or is the relationship between event perception and memory accounted for by general cognitive abilities? Two hundred and eight adults ranging from 20 to 79years old segmented movies of everyday events and attempted to remember the events afterwards. They also completed psychometric ability tests and tests measuring script knowledge for everyday events. Event segmentation and script knowledge both explained unique variance in event memory above and beyond the psychometric measures, and did so as strongly in older as in younger adults. These results suggest that event segmentation is a basic cognitive mechanism, important for memory across the lifespan.

A Bilingual Advantage for Episodic Memory in Older Adults

The ability to remember events - referred to as episodic memory - is typically subject to decline in older adulthood. Episodic memory decline has been attributed in part to less successful executive functioning, which may hinder an older adult's ability to implement controlled encoding and retrieval processes. Since bilingual older adults often show more successful executive functioning than monolinguals, they may be better able to maintain episodic memory. To examine this hypothesis, we compared bilingual and monolingual older adults on a picture scene recall task (assessing episodic memory) and a Simon task (assessing executive functioning). Bilinguals exhibited better episodic memory than their monolingual peers, recalling significantly more items overall. Within the bilingual group, earlier second language acquisition and more years speaking two languages were associated with better recall. Bilinguals also demonstrated higher executive functioning, and there was evidence that level of executive functioning was related to memory performance. Results indicate that extensive practice controlling two languages may benefit episodic memory in older adults.

Executive function mediates effects of white matter hyperintensities on episodic memory

This study examined the relationship between white matter hyperintensities (WMH) and executive functioning on episodic memory in a group of older adults who were cognitively normal or diagnosed with MCI or dementia. Volumetric magnetic resonance imaging (MRI) measures of total brain volume, white matter hyperintensity volume, and hippocampal volume along with age, education, and gender were evaluated as predictors of episodic memory. WMH were found to influence both episodic memory and executive functioning independently of other variables. The influence WMH on episodic memory was mediated by executive functioning and was completely eliminated when the interaction between executive functioning and hippocampal volume was entered in the regression model. The results indicate that executive functioning mediates the effects of WMH on episodic memory but that executive functioning and hippocampal volume can also interact such that executive functioning can exacerbate or ameliorate the influence of hippocampal volume on episodic memory.

Cognitive training in older adults with Mild Cognitive Impairment: Impact on cognitive and functional performance

Aging is associated with cognitive decline, yet this does not prevent older adults from finding ways to compensate for age-related deficits. Earlier studies have shown that cognitively unimpaired older adults can benefit from training programs. The efficacy of cognitive interventions among older adults without dementia but with cognitive decline (mild cognitive impairment, MCI) has not yet been widely tested.

Relations between cognitive abilities and measures of executive functioning

Although frequently mentioned in contemporary neuropsychology, the term executive functioning has been a source of considerable confusion. One way in which the meaning of a variable can be investigated involves examining its pattern of relations with established cognitive abilities. This method was applied to a variety of variables hypothesized to assess executive functioning in 2 data sets, 1 consisting of 328 adults between 18 and 93 years of age and a 2nd composite data set based on nearly 7,000 healthy adults between 18 and 95 years of age. Most of the hypothesized executive functioning variables were strongly related to reasoning and perceptual speed abilities, and very few had any unique relations with age after taking into consideration the relations of age through the cognitive abilities. These results raise questions about the extent to which neuropsychological tests of executive functioning measure a distinct dimension of variation in normal adults.

Influence of age and executive functioning on verbal memory of inpatients with depression

BACKGROUND

Despite many studies demonstrating memory and executive impairments in young and old depressed patients, the relationships between age, executive functioning and memory have not been evaluated in depression. The aim of this study was to investigate if older patients were more vulnerable than younger patients to the impact of depression on memory and if the differences between young and old depressed could be related to executive functioning.

METHODS

Forty-nine inpatients, with unipolar and bipolar depression, ranging in age from 19 to 72 years were compared with 70 controls on a verbal memory task. Age cut-off of 45 years was used as a categorical variable to divide subjects into subgroups. A subset of patients (n=41) was also evaluated with the modified version of the Wisconsin Card Sorting Test and separated into a non-dysexecutive group and a group of patients with mild-executive impairment.

RESULTS

Depressed patients exhibited memory deficits with a pattern of memory failure -- impaired free recall and normal cued recall and recognition -- interpreted as a retrieval problem. Both age and executive function influenced memory performance in depression, however neither group x age interaction nor age x executive status interaction were significant. Multiple regression analysis showed that free recall scores were related to age and psychomotor retardation in depressed patients.

CONCLUSION

Age and executive functioning have different influences on the memory performance of depressed patients. Our findings support an 'executive memory decline hypothesis' in young as well as old depressed patients. The memory deficits in depression may be associated with both trait and state factors and raise questions about the long-term cognitive functioning of patients with recurrent affective disorders.

Conceptual reasoning as a mediator of verbal recall in patients with multiple sclerosis

A number of intercorrelated factors, including level of neurologic impairment, age, and conceptual reasoning, appear to be related to memory performance among patients with Multiple Sclerosis (MS). A battery of neuropsychological tests was administered to 131 patients with MS ranging in age from 19 to 76 years, with a mean symptom duration of 12.3 years and an overall mild level of MS-related neurologic impairment. Regression analyses indicated that neurologic impairment and age each contributed uniquely to the prediction of delayed free recall of a word list. Furthermore, when the effect of conceptual reasoning was accounted for, neither neurologic impairment nor age were significantly related to recall. Thus, a mediated relation was confirmed, supporting the idea that a significant portion of neurologic-impairment-related and age-related differences in recall are due to differences in conceptual reasoning that are important for optimal performance on tests of recall. Additional analyses failed to support a similar mediated relation using recognition rather than recall as the measure of memory performance.