The Role of Similarity in Updating Numerical Information in Working Memory: Decomposing the Numerical Distance Effect

Effects of semantic relationship and preactivation on memory updating

Semantic relationship modulates working memory (WM) processes by promoting recall but impairing recognition. Updating is a core mechanism of WM responsible for its stability and flexibility; it allows maintenance of relevant information while removing no-longer relevant one. To our knowledge, no studies specifically investigated how WM updating may benefit from the processing of semantically related material. In the current study, two experiments were run with this aim. In Experiment 1, we found an advantage for semantically related words (vs. unrelated) regardless of their association type (i.e., taxonomic or thematic). A second experiment was run boosting semantic association through preactivation. Findings replicated those of Experiment 1 suggesting that preactivation was effective and improved semantic superiority. In sum, we demonstrated that long-term semantic associations benefitted the updating process, or more generally, overall WM function. In addition, pre-activating semantic nodes of a given word appears likely a process supporting WM and updating; thus, this may be the mechanism favoring word process and memorization in a semantically related text.

Long-term memory effects on working memory updating development

Long-term memory (LTM) associations appear as important to cognition as single memory contents. Previous studies on updating development have focused on cognitive processes and components, whereas our investigation examines how contents, associated with different LTM strength (strong or weak), might be differentially updated at different ages. To this end, we manipulated association strength of information given at encoding, in order to focus on updating pre-existing LTM associations; specifically, associations for letters. In particular, we controlled for letters usage frequency at the sub-lexical level. We used a task where we dissociated inhibition online (i.e., RTs for updating and controlling inhibition from the same set) and offline (i.e., RTs for controlling inhibition from previously updated sets). Mixed-effect analyses were conducted and showed a substantial behavioural cost when strong associations had to be dismantled online (i.e., longer RTs), compared to weak ones; here, in primary school age children. Interestingly, this effect was independent of age; in fact, children from 7–8 to 9–10 years were comparably sensitive to the strength of LTM associations in updating. However, older children were more effective in offline inhibitory control.

Focus Switching in Working Memory

Abstract. Focus switching in working memory involves accessing an object in the focus of attention in order to retrieve its content. Objects in working memory can be viewed as consisting of two types of information: contents (e.g., numerical information) and contexts (e.g., cues to retrieve the contents). This study examined the extent to which content retrieval and context access may be separated. Three experiments were carried out in which object switching and content retrieval were manipulated. In addition, the alternation between the retrieval operations was also manipulated. The main result was that content retrieval required time over and above that needed to access the object. This finding supports the idea that contexts and their contents may be accessed independently when an object is brought into the focus.

Age-related differences in working memory updating components

The aim of this study was to investigate possible age-related changes throughout childhood and adolescence in different component processes of working memory updating (WMU): retrieval, transformation, and substitution. A set of numerical WMU tasks was administered to four age groups (8-, 11-, 14-, and 21-year-olds). To isolate the effect of each of the WMU components, participants performed different versions of a task that included different combinations of the WMU components. The results showed an expected overall decrease in response times and an increase in accuracy performance with age. Most important, specific age-related changes in the retrieval component were found, demonstrating that the effect of retrieval on accuracy was larger in children than in adolescents or young adults. These findings indicate that the availability of representations from outside the focus of attention may change with age. Thus, the retrieval component of updating could contribute to the age-related changes observed in the performance of many updating tasks.

Magnitude Representation and Working Memory Updating in Children With Arithmetic and Reading Comprehension Disabilities

It has been argued that children with learning disabilities (LD) encounter severe problems in working memory (WM) tasks, especially when they need to update information stored in their WM. It is not clear, however, to what extent this is due to a generally poor updating ability or to a difficulty specific to the domain to be processed. To examine this issue, two groups of children with arithmetic or reading comprehension LD and a group of typically developing children (9 to 10 years old) were assessed using two updating tasks requiring to select the smallest numbers or objects presented. The results showed that children with an arithmetic disability failed in a number updating task, but not in the object updating task. The opposite was true for the group with poor reading comprehension, whose performance was worse in the object than in the number updating task. It may be concluded that the problem of WM updating in children with LD is also due to a poor representation of the material to be updated. In addition, our findings suggest that the mental representation of the size of objects relates to the semantic representation of the objects' properties and differs from the quantitative representation of numbers.

Age differences in working memory updating: the role of interference, focus switching and substituting information

Working memory updating (WMU) tasks require different elements in working memory (WM) to be maintained simultaneously, accessing one of these elements, and substituting its content. This study examined possible developmental changes from childhood to adulthood both in focus switching and substituting information in WM. In addition, possible age-related changes in interference due to representational overlap between the different elements simultaneously held in these tasks were examined. Children (8- and 11-year-olds), adolescents (14-year-olds) and younger adults (mean age=22 years) were administered a numerical updating memory task, in which updating and focus switching were manipulated. As expected, response times decreased and recall performance increased with age. More importantly, the time needed for focus switching was longer in children than in adolescents and younger adults. On the other hand, substitution of information and interference due to representational overlap were not affected by age. These results suggest that age-related changes in focus switching might mediate developmental changes in WMU performance.