Hindawi Publishing Corporation Child Development Research Volume 2013, Article ID 763808, 12 pages http://dx.doi.org/10.1155/2013/763808 Research Article Examining the Relative Contribution of Memory Updating, Attention Focus Switching, and Sustained Attention to Children’s Verbal Working Memory Span Beula M. Magimairaj and James W. Montgomery Communication Sciences and Disorders, Grover Center W 218, Ohio University, Athens, OH 45701, USA Correspondence should be addressed to Beula M. Magimairaj; magimair@ohio.edu Received 25 October 2012; Revised 22 January 2013; Accepted 1 February 2013 Academic Editor: Cheryl Dissanayake Copyright © 2013 B. M. Magimairaj and J. W. Montgomery. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Whereas considerable developmental memory research has examined the contributions of short-term memory, processing efciency, retention duration, and scope of attention to complex memory span, little is known about the infuence of controlled attention. Te present study investigated the relative infuence of three understudied attention mechanisms on the verbal working memory span of school-age children: memory updating; attention focus switching; and sustained attention. Results of general linear modeling revealed that, afer controlling for age, only updating accuracy emerged as a signifcant predictor of verbal working memory span. Memory updating speed (that subsumed attention focus switching speed) also contributed but was mediated by age. Te results extend the developmental memory literature by implicating the mechanism of memory updating and developmental improvement in speed of attention focus switching and updating as critical contributors to children’s verbal working memory. Teoretically, the results provide substantively new information about the role of domain-general executive attention in children’s verbal working memory. 1. Introduction Working memory (WM) refers to a limited-capacity system that functions to encode, store, and retrieve information being processed in any cognitive task [1–6]. Working memory is conventionally measured using complex memory span tasks that are characterized by maintenance of items during processing [7, 8]. Developmental memory research indicates that children’s WM system comprises the components of short-term memory storage, processing speed [9–11], and a central executive [2, 12–20]. Tere are considerable develop- mental data focusing on the infuence of storage and pro- cessing speed on children’s WM [10, 13, 21–24]. However, few studies have directly explored the contribution of attention mechanisms on WM [25]. Te present study, therefore, was designed to directly investigate the contribution of attention to school-age children’s verbal WM. Working memory, functionally defned as the ability to manage information storage and retrieval during an ongoing cognitive task, requires controlled attention toward both storage and processing [13, 14, 16, 19, 26–29]. Individuals with better controlled attention are better able than those with poorer attention to maintain more items while performing a cognitive activity [19]. Cowan and colleagues have proposed that WM is defned functionally as the number of informa- tion units/chunks that can be held in the scope of attention at any given point and attention control allows individuals to rapidly bring items from outside the scope of attention back into the scope of attention [16]. Barrouillet and colleagues [13, 30] have proposed the time-based resource-sharing model (TBRS) in which individuals in a rapid serial fashion switch their attention between processing and storage. If attention is captured by processing then it is unavailable for refreshing storage items.