Working memory and intraindividual variability in processing speed: A lifespan developmental and individual-differences study

Abstract

Working memory (WM) and intraindividual variability (IIV) in processing speed are both hypothesized to reflect general attentional processes. In the present study, we aimed at exploring the relationship between WM capacity and IIV in reaction times (RTs) and its possible variation with development across the lifespan. Two WM tasks and six RT tasks of varying complexity were analyzed in a sample of 539 participants, consisting of five age groups: two groups of children (9-10 and 11-12 years of age), one group of young adults, and two groups of older adults (59-69 and 70-89 years of age). Two approaches were adopted. First, low-span and high-span individuals were identified, and analyses of variance were conducted comparing these two groups within each age group and for each RT task. The results consistently showed a span effect in the youngest children and oldest adults: High-span individuals were significantly faster and less variable than low-span individuals. In contrast, in young adults no difference was observed between high-and lowspan individuals, whether in terms of their means or IIV. Second, multivariate analyses were conducted on the entire set of tasks, to determine whether IIV in RTs brought different information than the mean RT. The results showed that, although very strongly correlated, the mean and IIV in speed should be kept separate in terms of how they account for individual differences in WM. Overall, our results support the assumption of a link between WM capacity and IIV in RT, more strongly so in childhood and older adulthood.Keywords Aging . Development . Individual differences . Reaction time analyses/methods . Working memory . Intraindividual variabilityThe objective of the present article is to address the issue of the relationship between working memory (WM) capacity and within-task intraindividual variability (IIV) in reaction time (RT) tasks, investigating whether this relationship might vary across the lifespan. In this introduction, we will briefly present our approach to WM-in conformity with the demand of the editor of this special issue-and then discuss why a potential relationship can be hypothesized between WM and IIV and whether individual differences in WM could be related to IIV.As a number of researchers interested in developmental and/ or individual differences in WM, we consider the performance in WM tasks to be determined by a set of underlying attentional processes. These processes, such as the activation and inhibition of relevant informational units, are considered to become more efficient with age, accounting for part of cognitive development in children, and to vary in efficacy across individuals. We consider WM to be an index of what has frequently, and rather loosely, been labeled general resources. WM capacity, while remaining severely limited, increases with age both because of an increase in neurobiological mechanisms and because the use of resources becomes more efficient with experience. There is here a major point of departure between cognitive ex...

Perspectives on working memory: introduction to the special issue

“…Here, the focus is on the factors that drive this correlation. The articles by Chow and Conway (2015) and Mella, Fagot, Lecerf, and de Ribaupierre (2015) both present evidence that multiple factors contribute to general working memory capacity, consistent with BH, demonstrating that there are multiple cognitive abilities, and that not all measures of those abilities are strongly related to intelligence. Lilienthal, Rose, Tamez, Myerson, and Hale (2015) demonstrate that the ability to monitor the source of information is more important than the ability to inhibit irrelevant input in characterizing the difference between individuals with high and low general working memory capacity.…”

Leisure Activities and Change in Cognitive Stability: A Multivariate Approach

“…We analyzed data from the Geneva Variability Study (GVS), a longitudinal study in which participants are tested every two to two and a half years, on an extensive battery of neurocognitive tasks, mostly reaction time (RT) tasks but not only, especially designed to explore IIV [14,38]. The present paper focuses on the first four waves of data collection, i.e., a six- to seven-year period (mean interval of 6.25 years, standard deviation (SD) = 0.4).…”

“…Higher levels of IIV have been reported in patients with neurological diseases, such as Parkinson disease, Alzheimer disease, or mild cognitive impairment (MCI) [6,8,9,10,11]. In normal aging, the level of IIV has been associated with subsequent cognitive decline [12,13], working memory capacities [14], later MCI [15] and even with proximity to death [16]. All these findings converge to suggest that IIV is a meaningful indicator of processing efficiency in aging, and may provide, as suggested by some authors, unique information above and beyond information provided by average performance [3,17].…”

The Mid-Career Award Working out how working memory works: evidence from typical and atypical development

“…In other words, the Working out how 7 central executive is a theoretical construct invoked to account for the need to resist the effects of potentially distracting processing episodes within working memory tasks, not to carry out that processing; this distinction has not always been as clearly drawn as it needs to be. Indeed, I suggest that most accounts of working memory need to acknowledge the additional importance of processing speed on performance (see Barrouillet, Bernadin, & Camos, 2004, Fry & Hale, 2000Mella, Fagot, Lecerf, & Ribaupierre, 2015). For example, if one were to extend the Baddeley (1986) model, one might want to argue for three, rather than two, subcomponents of working memory.…”