The components of working memory updating: an experimental decomposition and individual differences

Abstract

Working memory updating (WMU) has been identified as a cognitive function of prime importance for
everyday tasks and has also been found to be a significant predictor of higher mental abilities. Yet, little is
known about the constituent processes of WMU. We suggest that operations required in a typical WMU task
can be decomposed into 3 major component processes: retrieval, transformation, and substitution. We report
a large-scale experiment that instantiated all possible combinations of those 3 component processes. Results
show that the 3 components make independent contributions to updating performance. We additionally
present structural equation models that link WMU task performance and working memory capacity (WMC)
measures. These feature the methodological advancement of estimating interindividual covariation and
experimental effects on mean updating measures simultaneously. The modeling results imply that WMC is a
strong predictor of WMU skills in general, although some component processes—in particular, substitution
skills—were independent of WMC. Hence, the reported predictive power ofWMUmeasures may rely largely
on common WM functions also measured in typical WMC tasks, although substitution skills may make an
independent contribution to predicting higher mental abilities.