The Roles of the Central Executive and Visuospatial Storage in Mental Arithmetic: A Comparison across Strategies

Paula J Hubber,Camilla Gilmore,Lucy Cragg

doi:10.1080/17470218.2013.838590

Abstract

Previous research has demonstrated that working memory plays an important role in arithmetic. Different arithmetical strategies rely on working memory to different extents—for example, verbal working memory has been found to be more important for procedural strategies, such as counting and decomposition, than for retrieval strategies. Surprisingly, given the close connection between spatial and mathematical skills, the role of visuospatial working memory has received less attention and is poorly understood. This study used a dual-task methodology to investigate the impact of a dynamic spatial n-back task (Experiment 1) and tasks loading the visuospatial sketchpad and central executive (Experiment 2) on adults’ use of counting, decomposition, and direct retrieval strategies for addition. While Experiment 1 suggested that visuospatial working memory plays an important role in arithmetic, especially when counting, the results of Experiment 2 suggested this was primarily due to the domain-general executive demands of the n-back task. Taken together, these results suggest that maintaining visuospatial information in mind is required when adults solve addition arithmetic problems by any strategy but the role of domain-general executive resources is much greater than that of the visuospatial sketchpad.

Highlights

Solving arithmetic problems requires a variety of cognitive processes and strategies
Performance on the visuospatial task did not differ across the different arithmetic strategies, F(1.58, 44.29) = 1.43, MSE = 0.14, p = .248, and there was no main effect of problem size, F(1, 28) = 2.65, MSE = 0.11, p = .115, or any significant interactions. This experiment employed a novel visuospatial working memory load task involving three different load levels combined with counting, decomposition, and retrieval strategies for answering addition problems
The difference in performance between the sum-only and zero-back conditions supports the inclusion of the zero-back task as a control condition and suggests that some of the effects reported in previous studies, which did not include such a control, may have been due to the general dual-task demands and not the working memory load itself

Summary

Introduction

Solving arithmetic problems requires a variety of cognitive processes and strategies. For simple sums an answer may be retrieved directly from memory, whilst more complex sums, such as those involving double digits, may require the use of procedural strategies, such as decomposition or counting. Successful execution of these strategies, those of a more procedural nature, has been shown to depend on working memory: the ability to store, monitor, and manipulate information in mind (see De Stefano & LeFevre, 2004; Raghubar, Barnes, & Hecht, 2010, for reviews). Less attention has been paid to the role of visuospatial working memory, despite considerable evidence of the association between numerical and spatial representations This is the focus of the current study. The authors would like to express their thanks to the three anonymous reviewers, whose comments on the original manuscript have helped to develop our ideas

Methods

Results

Conclusion