Fonctions exécutives, vieillissement cognitif et variations stratégiques

Assessment of the Relationship Between Executive Function and Cardiorespiratory Fitness in Healthy Older Adults

Associations between cardiorespiratory fitness and brain health in healthy older adults have been reported using a variety of cardiorespiratory fitness estimates (CRFe). Using commonly used methods to determine CRF, we assessed the relationship between CRFe and executive function performance. Healthy older adults (n = 60, mean age 68 years, 77% women), underwent three CRF tests: a Maximal Graded Exercise Test performed on a cycle ergometer, the Rockport Fitness Walking Test, and a Non-Exercise Prediction Equation. Executive function was assessed by a computerized cognitive assessment using an N-Back task (updating cost) and a Stroop task (interference cost, global and local switch cost). Multiple hierarchical regression analyses were conducted to assess the relationship between different CRFe and executive function performance. Regardless of age and education, cardiorespiratory fitness estimated from the Maximal Graded Exercise Test and the Rockport Fitness Walking Test was significantly associated with the global switch cost. All CRFe were associated with the interference cost. No association was observed between CRFe and local switching costs or the updating costs. In the present study, not all subcomponents of executive function were related to CRFe. Interestingly, the executive functions that were associated with CRFe are those that are known to be the most affected by aging.

What eye movements reveal about strategy encoding of words in younger and older adults

The main goal of this study was to explore the organizational strategies used by younger and older adults when encoding words, using eye-tracking. Participants had to learn a set of organizable words and then a set of non-organizable words, each presented on a single display. Participants were then asked to recall the words of each set in the order in which they came to their mind. Hence, the participants' encoding strategies revealed by eye-tracking could be directly related to their subsequent memory performance. The results confirmed the detrimental impact of aging on memory and the weaker use of organizational strategies by older adults during the recall phase. The eye-tracking data showed that when they encode the words, older adults do not look at them for as long as younger adults, probably because of slower eye movements. They also revealed that compared to younger adults, older adults were much less able to adapt their word scanning strategy according to whether the words to encode were organizable or not. Finally, the relationships that were found between the recall scores and the eye-tracking data suggest that the eye movement pattern at learning can predict how people will recall the words.

Initiation, Inhibition and Strategy Generation Across the Healthy Adult Lifespan

OBJECTIVE

Executive functions are crucial for adaptive behavior in novel contexts. In healthy aging, these abilities are more sensitive to dysfunction than other cognitive abilities. The effect of aging on initiation, inhibition, and strategy use was investigated via performance on the Hayling Sentence Completion Test.

METHOD

The standard Hayling Test and baseline cognitive tests were administered to healthy adults (N = 344), aged 18-89 years (cross-sectional study). Bivariate Pearson's correlations, partial correlations, and regression analyses were used to assess the impact of aging on the components of the Hayling Test.

RESULTS

There were significant positive correlations between age and response time for both Initiation and Suppression, and the number of Suppression Errors. Further, older age was negatively associated with strategy use. These findings remained significant after controlling for demographic factors such as education and crystallized intelligence and other cognitive functions sensitive to aging such as fluid intelligence, attention, working memory and semantic and phonemic word fluency.

CONCLUSIONS

This study provides clarification of the effect of age on the processes of initiation, inhibition, and strategy generation across the adult lifespan. The focus and analysis of strategy on the Hayling Test provides clinicians with an additional and valuable measure of executive functioning. That is, it provides insight into how older adults may be able to compensate for decline in these processes, and thus maximize quality of life and independence.

Optimizing memory strategy use in young and older adults: The role of metamemory and internal strategy use

We explored whether experiencing differential efficacy of reading and generation for memory in an initial learning trial led younger and older adults to improve recall of read items in a subsequent learning trial, leading to a reduction of the generation effect. In the first trial, generation improved the memory performance of both young and older adults. However, in Trial 2, the generation effect remained significant for older adults only, confirming that they did not change the way they processed read items, unlike the young adults. The older adults were also less spontaneously aware that generation led to better memory performance in the first trial, and, in contrast to the young adults, awareness did not result in a reduction of the generation effect. Moreover, the age-related differences in generation effect reduction were mediated by an independent measure of self-reported internal strategy use. However, when an appropriate environmental support was provided between both trials, older adults improved read items recall at the second trial as well as younger ones, leading to an elimination of the generation advantage for both groups. Environmental support reduced the implication of internal strategy use in the generation effect reduction, suggesting that age-related differences in the implementation of effective encoding processes in Trial 2 would be the consequence of a metamemory deficit, and reduced capacity to self-initiate internal strategies.

Cognitive Strategies and Physical Activity in Older Adults: A Discriminant Analysis

Background

Although a number of studies have examined sociodemographic, psychosocial, and environmental determinants of the level of physical activity (PA) for older people, little attention has been paid to the predictive power of cognitive strategies for independently living older adults. However, cognitive strategies have recently been considered to be critical in the management of day-to-day living.

Methods

Data were collected from 243 men and women aged 55 years and older living in France using face-to-face interviews between 2011 and 2013.

Results

A stepwise discriminant analysis selected five predictor variables (age, perceived health status, barriers' self-efficacy, internal memory, and attentional control strategies) of the level of PA. The function showed that the rate of correct prediction was 73% for the level of PA. The calculated discriminant function based on the five predictor variables is useful for detecting individuals at high risk of lapses once engaged in regular PA.

Conclusions

This study highlighted the need to consider cognitive functions as a determinant of the level of PA and, more specifically, those cognitive functions related to executive functions (internal memory and attentional control), to facilitate the maintenance of regular PA. These results are discussed in relation to successful aging.