Sandrine Vanneste

The effect of aging in recollective experience: The processing speed and executive functioning hypothesis

This study was designed to investigate the effects of aging on consciousness in recognition memory, using the Remember/Know/Guess procedure (Gardiner, J. M., & Richarson-Klavehn, A. (2000). Remembering and Knowing. In E. Tulving & F. I. M. Craik (Eds.), The Oxford Handbook of Memory. Oxford University Press.). In recognition memory, older participants report fewer occasions on which recognition is accompanied by recollection of the original encoding context. Two main hypotheses were tested: the speed mediation hypothesis (Salthouse, T. A. (1996). The processing-speed theory of adult age differences in cognition. Psychological Review, 3, 403-428) and the executive-aging hypothesis (West, R. L. (1996). An application of prefrontal cortex function theory to cognitive aging. Psychological Bulletin, 120, 272-292). A group of young and a group of older adults took a recognition test in which they classified their responses according to Gardiner, J. M., & Richarson-Klavehn, A. (2000). Remembering and Knowing. In E. Tulving & F. I. M. Craik (Eds.), The Oxford Handbook of Memory. Oxford University Press. remember-know-guess paradigm. Subsequently, participants completed processing speed and executive function tests. The results showed that among the older participants, R responses decreased, but K responses did not. Moreover, a hierarchical regression analysis supported the view that the effect of age in recollection experience is determined by frontal lobe integrity and not by diminution of processing speed.

Aging and self-reported internal and external memory strategy uses: The role of executive functioning

The aim of this study was to investigate the effect of advanced age on self-reported internal and external memory strategy uses, and whether this effect can be predicted by executive functioning. A sample of 194 participants aged 21 to 80 divided into three age groups (21-40, 41-60, 61-80) completed the two strategy scales of the Metamemory in Adulthood (MIA) questionnaire, differentiating between internal and external everyday memory strategy uses, and three tests of executive functioning. The results showed that: (1) the use of external memory strategies increased with age, whereas use of internal memory strategy decreased; (2) executive functioning appeared to be related only to internal strategies, the participants who reported the greatest use of internal strategies having the highest executive level; and (3) executive functioning accounted for a sizeable proportion of the age-related variance in internal strategy use. These findings suggest that older adults preferentially use external memory strategies to cope with everyday memory impairment due to aging. They also support the view that the age-related decrease in the implementation of internal memory strategies can be explained by the executive hypothesis of cognitive aging. This result parallels those observed using objective laboratory memory strategy measures and then supports the validity of self-reported memory strategy questionnaire.

Age-related changes in duration reproduction: Involvement of working memory processes

The aim of the present research was to study age-related changes in duration reproduction by differentiating the working memory processes underlying this time estimation task. We compared performances of young and elderly adults in a duration reproduction task performed in simple and concurrent task conditions. Participants were also administered working memory tests to measure storage and central executive functions. Findings indicated a differential involvement of working memory storage and central executive functions in age-related differences in temporal tasks. The limited storage capacities explained age-related changes in the simple task of duration reproduction, and the dysfunctioning of central executive functions accounted for age-related changes in duration reproduction performed in a concurrent task condition, which involves greater attentional resources.

Executive functioning and processing speed in age-related differences in memory: contribution of a coding task.

The aim of the present study was to examine executive dysfunctioning and decreased processing speed as potential mediators of age-related differences in episodic memory. We compared the performances of young and elderly adults in a free-recall task. Participants were also given tests to measure executive functions and perceptual processing speed and a coding task (the Digit Symbol Substitution Test, DSST). More precisely, we tested the hypothesis that executive functions would mediate the age-related differences observed in the free-recall task better than perceptual speed. We also tested the assumption that a coding task, assumed to involve both executive processes and perceptual speed, would be the best mediator of age-related differences in memory. Findings first confirmed that the DSST combines executive processes and perceptual speed. Secondly, they showed that executive functions are a significant mediator of age-related differences in memory, and that DSST performance is the best predictor.

Aging and strategic retrieval in a cued-recall test: The role of executive functions and fluid intelligence

Cued-recall in episodic memory was investigated in relation to low and high cognitive support at retrieval, executive function level and fluid intelligence level in 81 healthy adults divided first into two age groups (young and elderly adults). The first analyses showed that age-related differences were greater when a low cognitive support was provided to recall the words. An individual index of loss of performance when the number of cues was decreased was then calculated. Hierarchical regression analysis revealed that the executive functions measure (perseverative errors on the Wisconsin Card Sorting Test) was a better candidate than the fluid intelligence measure (Cattells culture fair test) to account for the age-related variance of the size of performance loss. These findings suggest that age differences in implementing strategic retrieval may be mainly due to a decline in executive functions.

Timing in Aging: The Role of Attention

This paper questions the issue of attentional capacity in changes in time processing with aging. Performances of young and old subjects were compared in a task involving an attentional sharing between three concurrent estimations of durations (6, 8, or 10 s). Depending upon the experimental condition, the subjects were instructed to simultaneously focus their attention onto one, two, or three target stimuli. The results showed that increased difficulty of the task, that is the increased number of concurrent temporal targets to monitor at a time, led to a greater disruption of timing performance in elderly people than in young adults. Temporal judgments of elderly were less accurate and more variable than those of young adults in the attentional sharing conditions (two or three target durations). The greater sensitivity to interference effects observed in the elderly is discussed in terms of age-related reduction of attentional resources and working-memory deficits.

Age-Related Cognitive Slowing: The Role of Spontaneous Tempo and Processing Speed

This research studied the relationships between two types of slowing observed in aging—loss of general processing speed and slowing of spontaneous tempo—in an attempt to test the assumption that there is an internal timing mechanism responsible for cognitive age-related decrease. Processing speed has been evaluated as a mediator of the relationship between age and working memory, concurrently with spontaneous tempo measures. The authors compared the performance of young and older adults on tasks involving spontaneous motor tempo, processing speed, and working memory. The findings confirmed the agerelated slowing of spontaneous motor tempo but did not indicate superiority of tempo mediation in the decline in working memory. Processing speed appeared to be a major mediator of working memory, but also of spontaneous tempo slowing.

Aging and implementation of encoding strategies in the generation of rhymes: The role of executive functions.

This experiment examines whether the age-related decrease in the generation effect of rhymes is mediated by executive functioning. Young and elderly adults read and generated pairs of rhyming words for subsequent recall. Participants were also administered neuropsychological tests (executive and mnemonic functions). Results showed that elderly adults performed less well on the neuropsychological tests and benefited less than the younger participants from the generation effect. Hierarchical regression analyses revealed that the executive functions composite score was correlated with the generation effect and that it accounted for a large proportion of the age-related variance of the size of this measure. This finding supports the view that the age-related decrement in strategic encoding implementation is due to a decrease of executive functioning.

Differential Involvement of Knowledge Representation and Executive Control in Episodic Memory Performance in Young and Older Adults

Craik and Bialystok (2006, 2008) postulated that examining the evolution of knowledge representation and control processes across the life span could help in understanding age-related cognitive changes. The present study explored the hypothesis that knowledge representation and control processes are differentially involved in the episodic memory performance of young and older adults. Young and older adults were administered a cued-recall task and tests of crystallized knowledge and executive functioning to measure representation and control processes, respectively. Results replicate the classic finding that executive and cued-recall performance decline with age, but crystallized-knowledge performance does not. Factor analysis confirmed the independence of representation and control. Correlation analyses showed that the memory performance of younger adults was correlated with representation but not with control measures, whereas the memory performance of older adults was correlated with both representation and control measures. Regression analyses indicated that the control factor was the main predictor of episodic-memory performance for older adults, with the representation factor adding an independent contribution, but the representation factor was the sole predictor for young adults. This finding supports the view that factors sustaining episodic memory vary from young adulthood to old age; representation was shown to be important throughout adulthood, and control was also important for older adults. The results also indicated that control and representation modulate age-group-related variance in episodic memory.

Effect of distinctive encoding on false recognition, discrimination, and decision criteria in young and elderly adults

In order to examine the effects of distinctive encoding on age-related differences in false memory and decision criteria, we used a standard recognition paradigm and manipulated three encoding conditions: control, general, and distinctive. The results revealed main effects of age and encoding condition on hits and false recognition, and interactions between these variables, with elderly adults benefiting more than young adults from the encoding tasks. In the distinctive encoding condition, the age-related difference on false recognition was eliminated. These findings are discussed in terms of an age-related deficit in self-initiated distinctive processing. Further analyses showed that elderly adults used a more lenient decision criterion than young adults. Distinctive encoding led all subjects to use stringent decision criteria, but did not eliminate age differences.