Delphine Fagot

Working Memory and Inhibitory Control across the Life Span: Intrusion Errors in the Reading Span Test

The aim of this study was to examine to what extent inhibitory control and working memory capacity are related across the life span. Intrusion errors committed by children and younger and older adults were investigated in two versions of the Reading Span Test. In Experiment 1, a mixed Reading Span Test with items of various list lengths was administered. Older adults and children recalled fewer correct words and produced more intrusions than did young adults. Also, age-related differences were found in the type of intrusions committed. In Experiment 2, an adaptive Reading Span Test was administered, in which the list length of items was adapted to each individual’s working memory capacity. Age groups differed neither on correct recall nor on the rate of intrusions, but they differed on the type of intrusions. Altogether, these findings indicate that the availability of attentional resources influences the efficiency of inhibition across the life span.

The association of leisure activities in middle adulthood with cognitive performance in old age: the moderating role of educational level.

Background: One of the fundamental challenges for gerontological research is how to maintain and promote intact cognitive functioning in old age. Previous research revealed that high educational level, good health status, and an active lifestyle during adulthood seem to be protective against cognitive impairment in old age. However, up to now, a detailed examination of the interaction of these relations based on a broader variety of activities and considering past and current activities is missing. Objective: The present study set out to extend the literature by investigating in more detail the interactions of educational level and health status with a broad variety of past and current leisure activities in their association with cognitive functioning in a large sample of older adults with a wide age range. Methods: A total of 2,812 older adults (aged 65-101 years) served as the sample for the present study. A test on verbal abilities and one on processing speed were applied. In addition, individuals were retrospectively interviewed regarding their educational level, current general health status, and 18 leisure activities (in terms of currently performed activities and those that had been carried out at the age of 45 years). Results: Regressions indicated that engaging in more current activities and in more activities at the age of 45 years (both analyzed as an overall activity measure) was related to better cognitive performance in old age (r values up to 0.39, p values <0.001). These associations were more pronounced in individuals with a low (compared to a high) educational level. Conclusion: Present results suggest that an active lifestyle during middle adulthood may be related to better cognitive functioning in old age, particularly in individuals with a low educational level. These findings are discussed with respect to models of cognitive aging.

Dispersion in cognitive functioning: Age differences over the lifespan

ABSTRACT Introduction: A growing body of research suggests that intraindividual variability (IIV) may bring specific information on cognitive functioning, additional to that provided by the mean. The present paper focuses on dispersion, that is IIV across tasks, and its developmental trend across the lifespan. Method: A total of 557 participants (9–89 years) were administered a battery of response time (RT) tasks and of working memory (WM) tasks. Dispersion was analyzed separately for the two types of tasks. Results: Dispersion across RT tasks showed a U-shaped age differences trend, young adults being less variable than both children and older adults. Dispersion across WM tasks (using accuracy scores) presented an opposite developmental trend. A cluster analysis revealed a group of individuals showing relatively little dispersion and good overall performance (faster in RTs and better in WM), contrasted with a group of individuals showing a large dispersion in the RT tasks as well as poorer overall performance. All young adults were grouped in the first cluster; children and older adults were distributed in both clusters. Conclusion: It is concluded that (a) across-task IIV is relatively large in the entire sample and should not be neglected, (b) children and older adults show a larger dispersion than young adults, but only as far as the RT tasks are concerned, (c) variability in RTs and variability in WM performance do not reflect the same phenomenon.

The effect of age and individual differences in attentional control: A sample case using the Hayling test

Individual differences in working memory (WM) have been shown to reflect the ability to control attention in order to prevent interference. This study examines the role of WM capacity in resisting interference in the Hayling task, in samples of younger and older adults. In each age group, high and low WM span individuals had to complete high-cloze sentences with either expected words (initiation) or words providing no meaning to the sentences (interference). Results showed increased response times and decreased correct responses in interference, as compared to initiation. As interference increased, older adults demonstrated lower accuracy than younger ones. Further, low spans demonstrated higher interference costs than high spans on accuracy, while the reverse pattern was found for response times. Our findings suggest that both age and individual differences in WM capacity need to be considered to account for differences in the ability to resist to interference.

The association of educational attainment, cognitive level of job, and leisure activities during the course of adulthood with cognitive performance in old age: the role of openness to experience.

BACKGROUND The relevance of mental health for everyday life functioning and well-being is crucial. In this context, higher educational attainment, higher cognitive level of ones occupation, and more engaging in stimulating leisure activities have been found to be associated with better cognitive functioning in old age. Yet, the detailed pattern of the potential interplay of such a cognitively engaged lifestyle with personality dimensions, such as openness to experience, in their relations to cognitive functioning remains unclear. METHODS Two thousand eight hundred and twelve older adults served as sample for the present study. Psychometric tests on verbal abilities and processing speed were administered. In addition, individuals were retrospectively interviewed on their educational attainment, occupation, and regarding 18 leisure activities that had been carried out in mid-life. Moreover, openness to experience was assessed. RESULTS We found that the effect of openness to experience on cognitive functioning was mediated by educational attainment, cognitive level of job, and engaging in different leisure activities. Data were not better described by alternative moderation models testing for interactive (i.e. dependent) effects of openness to experience and cognitively stimulating engagement. CONCLUSIONS To explain interindividual differences in cognitive functioning in old age, present data are in line with a mechanism in which individuals with high openness to experience may have been more engaged in stimulating activities in early and mid-life. Possibly by increasing their cognitive reserve throughout adulthood, this may finally enhance their cognitive performance level later in old age.

Adults’ Versus Children’s Performance on the Stroop Task: Insights From Ex-Gaussian Analysis

In the Geneva Variability Study, the Stroop task was administered to children and young adults. Interference and facilitation effects were investigated by comparing mean reaction times (RTs) and applying ex-Gaussian distribution analysis. Our analyses were motivated by three goals: First, we aimed to replicate the results obtained with young adults by Spieler, Balota, and Faust (2000); second, we applied this method to childrens data; third, the question of age-related differences in these inhibitory processes was investigated with the ex-Gaussian approach. In young adults, findings pertaining to the interference effect reported by Spieler et al. (2000) were replicated; in children, the interference effect was only manifested in the estimated Gaussian parameters (Mean RT, μ, σ); facilitation effects were only observed in children. The substantive meaning of the results and the advantages of ex-Gaussian analyses for describing RT distributions are discussed.

Representation of Vulnerability and the Elderly. A Total Survey Error Perspective on the VLV Survey

This chapter focuses on the “Vivre-Leben-Vivere” (VLV) research and explains how the team in charge has dealt with the issue of representing old people in Switzerland and the vulnerable persons within this population. For this purpose, we draw inspiration from the “total survey error” perspective and discuss the procedures that were used to collect the information, but also the quality of the information itself. We present some of VLV’s methodological choices, such as the contact procedures that were designed to “capture” the most vulnerable individuals, especially in a context where refusal rates for participation in surveys are increasing. We also consider the missing values in responses to some “complex” topics. Results show that participation rates are highly related to the effort that was made in order to recruit the individuals. This is critical for the VLV project, where people can show different degrees of vulnerability related to age, health, and/or poverty. In this sense, efforts such as repeated calls, home visits, and the proxy procedure were successful both in a general perspective and more specifically for a fair inclusion of vulnerable persons in the survey. At the same time, the non-response rates show to what extent it is difficult to explain the personal decision not to respond to a survey or to a question. We can find some traces of “interviewer effects” in the analysis of item non-responses, which we have done by using a logistic regression for one of the psychological tests included in VLV. Some aspects relate to interviewer and respondent characteristics, but others relate to the interview context, all highlighting the complex social interactions at stake.

The relation of the number of languages spoken to performance in different cognitive abilities in old age

ABSTRACT Introduction: Findings on the association of speaking different languages with cognitive functioning in old age are inconsistent and inconclusive so far. Therefore, the present study set out to investigate the relation of the number of languages spoken to cognitive performance and its interplay with several other markers of cognitive reserve in a large sample of older adults. Method: Two thousand eight hundred and twelve older adults served as sample for the present study. Psychometric tests on verbal abilities, basic processing speed, and cognitive flexibility were administered. In addition, individuals were interviewed on their different languages spoken on a regular basis, educational attainment, occupation, and engaging in different activities throughout adulthood. Results: Higher number of languages regularly spoken was significantly associated with better performance in verbal abilities and processing speed, but unrelated to cognitive flexibility. Regression analyses showed that the number of languages spoken predicted cognitive performance over and above leisure activities/physical demand of job/gainful activity as respective additional predictor, but not over and above educational attainment/cognitive level of job as respective additional predictor. There was no significant moderation of the association of the number of languages spoken with cognitive performance in any model. Conclusions: Present data suggest that speaking different languages on a regular basis may additionally contribute to the build-up of cognitive reserve in old age. Yet, this may not be universal, but linked to verbal abilities and basic cognitive processing speed. Moreover, it may be dependent on other types of cognitive stimulation that individuals also engaged in during their life course.

The Relation of Obesity to Performance in Verbal Abilities, Processing Speed, and Cognitive Flexibility in Old Age: The Role of Cognitive Reserve

Aims: The present study set out to investigate the relation of obesity to performance in verbal abilities, processing speed, and cognitive flexibility and its interplay with key correlates of cognitive reserve in a large sample of older adults. Methods: A total of 2,812 older adults served as a sample for the present study. Psychometric tests on verbal abilities, processing speed, and cognitive flexibility were administered. In addition, individuals were interviewed on their weight and height (to calculate body mass index; BMI), educational attainment, occupation, and engaging in different activities throughout adulthood. Results: Obesity (BMI ≥30) was significantly associated with a lower performance in verbal abilities, processing speed, and cognitive flexibility. Moderation analyses showed that obesity was related to lower processing speed and cognitive flexibility only in individuals with low engagement in activities and low education. Hierarchical regression analyses showed that obesity was not related to any of the three investigated cognitive performance measures when cognitive reserve in early and midlife was taken into account. Conclusion: Present data suggest that cognitive reserve accumulated during the life course may reduce the detrimental influences of obesity on cognitive functioning in old age.

Investigating Discontinuity of Age Relations in Cognitive Functioning, General Health Status, Activity Participation, and Life Satisfaction between Young-Old and Old-Old Age.

Health research suggests that findings on young-old adults cannot be generalized to old-old adults and thus that old-old age seems not a simple continuation of young-old age due to qualitative changes that result in a discontinuity in old age. Specifically, it would be of conceptual and methodological importance to inform research regarding estimates around which chronological age the beginning of old-old age could be placed at a population level, and whether this is universal or domain-specific. To derive such criteria, we investigated potential discontinuity of age relations between young-old and old-old age in a large population-based sample considering measures in different domains (processing speed, verbal abilities, general health status, activity participation, and life satisfaction). For processing speed, verbal abilities, general health status, and life satisfaction we observed some very small indication that there might be a discontinuity of age relations at the end of individuals’ eighties, and for activity participation already at the beginning of individuals’ eighties. In conclusion, models conceptualizing aging as a gradual development might not suffice to adequately represent the differences between the stages of young-old and old-old age due to some very small indication that there might be discontinuity in late adulthood.